diff --git a/composer.json b/composer.json
index 90e80895..d5fd7c0b 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
         "vendor-dir": "composer"
     },
     "require-dev": {
-        "codeigniter/framework": "^3.0",
+        "codeigniter/framework": "~3.1.4",
         "phpunit/phpunit": "^5.6"
     },
     "require": {
diff --git a/composer.lock b/composer.lock
index f6365add..0640416f 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,6 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "52a00fed1a89eb4d3d6321de418669f0",
     "content-hash": "fe4302679c1523cf63192337d8f4a61f",
     "packages": [
         {
@@ -53,7 +52,7 @@
                 "captcha",
                 "spam"
             ],
-            "time": "2015-09-11 15:23:20"
+            "time": "2015-09-11T15:23:20+00:00"
         },
         {
             "name": "phpmailer/phpmailer",
@@ -114,29 +113,30 @@
                 }
             ],
             "description": "PHPMailer is a full-featured email creation and transfer class for PHP",
-            "time": "2015-11-01 10:15:28"
+            "time": "2015-11-01T10:15:28+00:00"
         }
     ],
     "packages-dev": [
         {
             "name": "codeigniter/framework",
-            "version": "3.0.6",
+            "version": "3.1.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/bcit-ci/CodeIgniter.git",
-                "reference": "8082544c5b4b33175790f505587e202e3ca9e488"
+                "reference": "873608df8be83420474e3cf9fc749a8ed12a6c09"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/bcit-ci/CodeIgniter/zipball/8082544c5b4b33175790f505587e202e3ca9e488",
-                "reference": "8082544c5b4b33175790f505587e202e3ca9e488",
+                "url": "https://api.github.com/repos/bcit-ci/CodeIgniter/zipball/873608df8be83420474e3cf9fc749a8ed12a6c09",
+                "reference": "873608df8be83420474e3cf9fc749a8ed12a6c09",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.2.4"
             },
             "require-dev": {
-                "mikey179/vfsstream": "1.1.*"
+                "mikey179/vfsstream": "1.1.*",
+                "phpunit/phpunit": "4.* || 5.*"
             },
             "suggest": {
                 "paragonie/random_compat": "Provides better randomness in PHP 5.x"
@@ -148,7 +148,7 @@
             ],
             "description": "The CodeIgniter framework",
             "homepage": "https://codeigniter.com",
-            "time": "2016-03-21 16:26:30"
+            "time": "2017-03-20T15:51:08+00:00"
         },
         {
             "name": "doctrine/instantiator",
@@ -202,7 +202,7 @@
                 "constructor",
                 "instantiate"
             ],
-            "time": "2015-06-14 21:17:01"
+            "time": "2015-06-14T21:17:01+00:00"
         },
         {
             "name": "myclabs/deep-copy",
@@ -244,7 +244,7 @@
                 "object",
                 "object graph"
             ],
-            "time": "2016-10-31 17:19:45"
+            "time": "2016-10-31T17:19:45+00:00"
         },
         {
             "name": "phpdocumentor/reflection-common",
@@ -298,7 +298,7 @@
                 "reflection",
                 "static analysis"
             ],
-            "time": "2015-12-27 11:43:31"
+            "time": "2015-12-27T11:43:31+00:00"
         },
         {
             "name": "phpdocumentor/reflection-docblock",
@@ -343,7 +343,7 @@
                 }
             ],
             "description": "With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.",
-            "time": "2016-09-30 07:12:33"
+            "time": "2016-09-30T07:12:33+00:00"
         },
         {
             "name": "phpdocumentor/type-resolver",
@@ -390,7 +390,7 @@
                     "email": "me@mikevanriel.com"
                 }
             ],
-            "time": "2016-06-10 07:14:17"
+            "time": "2016-06-10T07:14:17+00:00"
         },
         {
             "name": "phpspec/prophecy",
@@ -452,7 +452,7 @@
                 "spy",
                 "stub"
             ],
-            "time": "2016-06-07 08:13:47"
+            "time": "2016-06-07T08:13:47+00:00"
         },
         {
             "name": "phpunit/php-code-coverage",
@@ -515,7 +515,7 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2016-11-01 05:06:24"
+            "time": "2016-11-01T05:06:24+00:00"
         },
         {
             "name": "phpunit/php-file-iterator",
@@ -562,7 +562,7 @@
                 "filesystem",
                 "iterator"
             ],
-            "time": "2015-06-21 13:08:43"
+            "time": "2015-06-21T13:08:43+00:00"
         },
         {
             "name": "phpunit/php-text-template",
@@ -603,7 +603,7 @@
             "keywords": [
                 "template"
             ],
-            "time": "2015-06-21 13:50:34"
+            "time": "2015-06-21T13:50:34+00:00"
         },
         {
             "name": "phpunit/php-timer",
@@ -647,7 +647,7 @@
             "keywords": [
                 "timer"
             ],
-            "time": "2016-05-12 18:03:57"
+            "time": "2016-05-12T18:03:57+00:00"
         },
         {
             "name": "phpunit/php-token-stream",
@@ -696,7 +696,7 @@
             "keywords": [
                 "tokenizer"
             ],
-            "time": "2015-09-15 10:49:45"
+            "time": "2015-09-15T10:49:45+00:00"
         },
         {
             "name": "phpunit/phpunit",
@@ -778,7 +778,7 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2016-10-25 07:40:25"
+            "time": "2016-10-25T07:40:25+00:00"
         },
         {
             "name": "phpunit/phpunit-mock-objects",
@@ -837,7 +837,7 @@
                 "mock",
                 "xunit"
             ],
-            "time": "2016-10-09 07:01:45"
+            "time": "2016-10-09T07:01:45+00:00"
         },
         {
             "name": "sebastian/code-unit-reverse-lookup",
@@ -882,7 +882,7 @@
             ],
             "description": "Looks up which function or method a line of code belongs to",
             "homepage": "https://github.com/sebastianbergmann/code-unit-reverse-lookup/",
-            "time": "2016-02-13 06:45:14"
+            "time": "2016-02-13T06:45:14+00:00"
         },
         {
             "name": "sebastian/comparator",
@@ -946,7 +946,7 @@
                 "compare",
                 "equality"
             ],
-            "time": "2015-07-26 15:48:44"
+            "time": "2015-07-26T15:48:44+00:00"
         },
         {
             "name": "sebastian/diff",
@@ -998,7 +998,7 @@
             "keywords": [
                 "diff"
             ],
-            "time": "2015-12-08 07:14:41"
+            "time": "2015-12-08T07:14:41+00:00"
         },
         {
             "name": "sebastian/environment",
@@ -1048,7 +1048,7 @@
                 "environment",
                 "hhvm"
             ],
-            "time": "2016-08-18 05:49:44"
+            "time": "2016-08-18T05:49:44+00:00"
         },
         {
             "name": "sebastian/exporter",
@@ -1115,7 +1115,7 @@
                 "export",
                 "exporter"
             ],
-            "time": "2016-06-17 09:04:28"
+            "time": "2016-06-17T09:04:28+00:00"
         },
         {
             "name": "sebastian/global-state",
@@ -1166,7 +1166,7 @@
             "keywords": [
                 "global state"
             ],
-            "time": "2015-10-12 03:26:01"
+            "time": "2015-10-12T03:26:01+00:00"
         },
         {
             "name": "sebastian/object-enumerator",
@@ -1212,7 +1212,7 @@
             ],
             "description": "Traverses array structures and object graphs to enumerate all referenced objects",
             "homepage": "https://github.com/sebastianbergmann/object-enumerator/",
-            "time": "2016-01-28 13:25:10"
+            "time": "2016-01-28T13:25:10+00:00"
         },
         {
             "name": "sebastian/recursion-context",
@@ -1265,7 +1265,7 @@
             ],
             "description": "Provides functionality to recursively process PHP variables",
             "homepage": "http://www.github.com/sebastianbergmann/recursion-context",
-            "time": "2015-11-11 19:50:13"
+            "time": "2015-11-11T19:50:13+00:00"
         },
         {
             "name": "sebastian/resource-operations",
@@ -1307,7 +1307,7 @@
             ],
             "description": "Provides a list of PHP built-in functions that operate on resources",
             "homepage": "https://www.github.com/sebastianbergmann/resource-operations",
-            "time": "2015-07-28 20:34:47"
+            "time": "2015-07-28T20:34:47+00:00"
         },
         {
             "name": "sebastian/version",
@@ -1350,7 +1350,7 @@
             ],
             "description": "Library that helps with managing the version number of Git-hosted PHP projects",
             "homepage": "https://github.com/sebastianbergmann/version",
-            "time": "2016-02-04 12:56:52"
+            "time": "2016-02-04T12:56:52+00:00"
         },
         {
             "name": "symfony/yaml",
@@ -1399,7 +1399,7 @@
             ],
             "description": "Symfony Yaml Component",
             "homepage": "https://symfony.com",
-            "time": "2016-10-24 18:41:13"
+            "time": "2016-10-24T18:41:13+00:00"
         },
         {
             "name": "webmozart/assert",
@@ -1449,7 +1449,7 @@
                 "check",
                 "validate"
             ],
-            "time": "2016-08-09 15:02:57"
+            "time": "2016-08-09T15:02:57+00:00"
         }
     ],
     "aliases": [],
diff --git a/src/system/core/Benchmark.php b/src/system/core/Benchmark.php
index b1d74f78..b3ac79c6 100644
--- a/src/system/core/Benchmark.php
+++ b/src/system/core/Benchmark.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/core/CodeIgniter.php b/src/system/core/CodeIgniter.php
index 3eb3e057..880abab5 100644
--- a/src/system/core/CodeIgniter.php
+++ b/src/system/core/CodeIgniter.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -55,7 +55,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @var	string
  *
  */
-	define('CI_VERSION', '3.0.6');
+	const CI_VERSION = '3.1.4';
 
 /*
  * ------------------------------------------------------
@@ -67,7 +67,10 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 		require_once(APPPATH.'config/'.ENVIRONMENT.'/constants.php');
 	}
 
-	require_once(APPPATH.'config/constants.php');
+	if (file_exists(APPPATH.'config/constants.php'))
+	{
+		require_once(APPPATH.'config/constants.php');
+	}
 
 /*
  * ------------------------------------------------------
@@ -416,14 +419,29 @@ if ( ! is_php('5.4'))
 			$params = array($method, array_slice($URI->rsegments, 2));
 			$method = '_remap';
 		}
-		// WARNING: It appears that there are issues with is_callable() even in PHP 5.2!
-		// Furthermore, there are bug reports and feature/change requests related to it
-		// that make it unreliable to use in this context. Please, DO NOT change this
-		// work-around until a better alternative is available.
-		elseif ( ! in_array(strtolower($method), array_map('strtolower', get_class_methods($class)), TRUE))
+		elseif ( ! method_exists($class, $method))
 		{
 			$e404 = TRUE;
 		}
+		/**
+		 * DO NOT CHANGE THIS, NOTHING ELSE WORKS!
+		 *
+		 * - method_exists() returns true for non-public methods, which passes the previous elseif
+		 * - is_callable() returns false for PHP 4-style constructors, even if there's a __construct()
+		 * - method_exists($class, '__construct') won't work because CI_Controller::__construct() is inherited
+		 * - People will only complain if this doesn't work, even though it is documented that it shouldn't.
+		 *
+		 * ReflectionMethod::isConstructor() is the ONLY reliable check,
+		 * knowing which method will be executed as a constructor.
+		 */
+		elseif ( ! is_callable(array($class, $method)) && strcasecmp($class, $method) === 0)
+		{
+			$reflection = new ReflectionMethod($class, $method);
+			if ( ! $reflection->isPublic() OR $reflection->isConstructor())
+			{
+				$e404 = TRUE;
+			}
+		}
 	}
 
 	if ($e404)
diff --git a/src/system/core/Common.php b/src/system/core/Common.php
index b87ce4d6..2fd5c580 100644
--- a/src/system/core/Common.php
+++ b/src/system/core/Common.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -319,17 +319,13 @@ if ( ! function_exists('get_mimes'))
 
 		if (empty($_mimes))
 		{
+			$_mimes = file_exists(APPPATH.'config/mimes.php')
+				? include(APPPATH.'config/mimes.php')
+				: array();
+
 			if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
 			{
-				$_mimes = include(APPPATH.'config/'.ENVIRONMENT.'/mimes.php');
-			}
-			elseif (file_exists(APPPATH.'config/mimes.php'))
-			{
-				$_mimes = include(APPPATH.'config/mimes.php');
-			}
-			else
-			{
-				$_mimes = array();
+				$_mimes = array_merge($_mimes, include(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'));
 			}
 		}
 
@@ -355,7 +351,7 @@ if ( ! function_exists('is_https'))
 		{
 			return TRUE;
 		}
-		elseif (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https')
+		elseif (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) === 'https')
 		{
 			return TRUE;
 		}
@@ -410,11 +406,6 @@ if ( ! function_exists('show_error'))
 		if ($status_code < 100)
 		{
 			$exit_status = $status_code + 9; // 9 is EXIT__AUTO_MIN
-			if ($exit_status > 125) // 125 is EXIT__AUTO_MAX
-			{
-				$exit_status = 1; // EXIT_ERROR
-			}
-
 			$status_code = 500;
 		}
 		else
@@ -544,13 +535,18 @@ if ( ! function_exists('set_status_header'))
 				416	=> 'Requested Range Not Satisfiable',
 				417	=> 'Expectation Failed',
 				422	=> 'Unprocessable Entity',
+				426	=> 'Upgrade Required',
+				428	=> 'Precondition Required',
+				429	=> 'Too Many Requests',
+				431	=> 'Request Header Fields Too Large',
 
 				500	=> 'Internal Server Error',
 				501	=> 'Not Implemented',
 				502	=> 'Bad Gateway',
 				503	=> 'Service Unavailable',
 				504	=> 'Gateway Timeout',
-				505	=> 'HTTP Version Not Supported'
+				505	=> 'HTTP Version Not Supported',
+				511	=> 'Network Authentication Required',
 			);
 
 			if (isset($stati[$code]))
@@ -566,12 +562,12 @@ if ( ! function_exists('set_status_header'))
 		if (strpos(PHP_SAPI, 'cgi') === 0)
 		{
 			header('Status: '.$code.' '.$text, TRUE);
+			return;
 		}
-		else
-		{
-			$server_protocol = isset($_SERVER['SERVER_PROTOCOL']) ? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.1';
-			header($server_protocol.' '.$code.' '.$text, TRUE, $code);
-		}
+
+		$server_protocol = (isset($_SERVER['SERVER_PROTOCOL']) && in_array($_SERVER['SERVER_PROTOCOL'], array('HTTP/1.0', 'HTTP/1.1', 'HTTP/2'), TRUE))
+			? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.1';
+		header($server_protocol.' '.$code.' '.$text, TRUE, $code);
 	}
 }
 
@@ -598,7 +594,7 @@ if ( ! function_exists('_error_handler'))
 	 */
 	function _error_handler($severity, $message, $filepath, $line)
 	{
-		$is_error = (((E_ERROR | E_COMPILE_ERROR | E_CORE_ERROR | E_USER_ERROR) & $severity) === $severity);
+		$is_error = (((E_ERROR | E_PARSE | E_COMPILE_ERROR | E_CORE_ERROR | E_USER_ERROR) & $severity) === $severity);
 
 		// When an error occurred, set the status header to '500 Internal Server Error'
 		// to indicate to the client something went wrong.
@@ -656,6 +652,7 @@ if ( ! function_exists('_exception_handler'))
 		$_error =& load_class('Exceptions', 'core');
 		$_error->log_exception('error', 'Exception: '.$exception->getMessage(), $exception->getFile(), $exception->getLine());
 
+		is_cli() OR set_status_header(500);
 		// Should we display the error?
 		if (str_ireplace(array('off', 'none', 'no', 'false', 'null'), '', ini_get('display_errors')))
 		{
@@ -716,8 +713,9 @@ if ( ! function_exists('remove_invisible_characters'))
 		// carriage return (dec 13) and horizontal tab (dec 09)
 		if ($url_encoded)
 		{
-			$non_displayables[] = '/%0[0-8bcef]/';	// url encoded 00-08, 11, 12, 14, 15
-			$non_displayables[] = '/%1[0-9a-f]/';	// url encoded 16-31
+			$non_displayables[] = '/%0[0-8bcef]/i';	// url encoded 00-08, 11, 12, 14, 15
+			$non_displayables[] = '/%1[0-9a-f]/i';	// url encoded 16-31
+			$non_displayables[] = '/%7f/i';	// url encoded 127
 		}
 
 		$non_displayables[] = '/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]+/S';	// 00-08, 11, 12, 14-31, 127
@@ -821,7 +819,7 @@ if ( ! function_exists('function_usable'))
 	 * terminate script execution if a disabled function is executed.
 	 *
 	 * The above described behavior turned out to be a bug in Suhosin,
-	 * but even though a fix was commited for 0.9.34 on 2012-02-12,
+	 * but even though a fix was committed for 0.9.34 on 2012-02-12,
 	 * that version is yet to be released. This function will therefore
 	 * be just temporary, but would probably be kept for a few years.
 	 *
diff --git a/src/system/core/Config.php b/src/system/core/Config.php
index ca6fb379..cda62241 100644
--- a/src/system/core/Config.php
+++ b/src/system/core/Config.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -319,7 +319,7 @@ class CI_Config {
 			}
 		}
 
-		return $base_url.ltrim($this->_uri_string($uri), '/');
+		return $base_url.$this->_uri_string($uri);
 	}
 
 	// -------------------------------------------------------------
@@ -337,11 +337,8 @@ class CI_Config {
 	{
 		if ($this->item('enable_query_strings') === FALSE)
 		{
-			if (is_array($uri))
-			{
-				$uri = implode('/', $uri);
-			}
-			return trim($uri, '/');
+			is_array($uri) && $uri = implode('/', $uri);
+			return ltrim($uri, '/');
 		}
 		elseif (is_array($uri))
 		{
diff --git a/src/system/core/Controller.php b/src/system/core/Controller.php
index 83b3df26..59a91673 100644
--- a/src/system/core/Controller.php
+++ b/src/system/core/Controller.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/core/Exceptions.php b/src/system/core/Exceptions.php
index a1c6a197..47d153f4 100644
--- a/src/system/core/Exceptions.php
+++ b/src/system/core/Exceptions.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -207,7 +207,6 @@ class CI_Exceptions {
 		}
 		else
 		{
-			set_status_header(500);
 			$templates_path .= 'html'.DIRECTORY_SEPARATOR;
 		}
 
diff --git a/src/system/core/Hooks.php b/src/system/core/Hooks.php
index 856795cb..f2d6f21c 100644
--- a/src/system/core/Hooks.php
+++ b/src/system/core/Hooks.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/core/Input.php b/src/system/core/Input.php
index a7c9ecd0..af4f87c1 100644
--- a/src/system/core/Input.php
+++ b/src/system/core/Input.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -359,7 +359,7 @@ class CI_Input {
 	 * @param	bool		$httponly	Whether to only makes the cookie accessible via HTTP (no javascript)
 	 * @return	void
 	 */
-	public function set_cookie($name, $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = FALSE, $httponly = FALSE)
+	public function set_cookie($name, $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = NULL, $httponly = NULL)
 	{
 		if (is_array($name))
 		{
@@ -388,15 +388,13 @@ class CI_Input {
 			$path = config_item('cookie_path');
 		}
 
-		if ($secure === FALSE && config_item('cookie_secure') === TRUE)
-		{
-			$secure = config_item('cookie_secure');
-		}
+		$secure = ($secure === NULL && config_item('cookie_secure') !== NULL)
+			? (bool) config_item('cookie_secure')
+			: (bool) $secure;
 
-		if ($httponly === FALSE && config_item('cookie_httponly') !== FALSE)
-		{
-			$httponly = config_item('cookie_httponly');
-		}
+		$httponly = ($httponly === NULL && config_item('cookie_httponly') !== NULL)
+			? (bool) config_item('cookie_httponly')
+			: (bool) $httponly;
 
 		if ( ! is_numeric($expire))
 		{
@@ -519,9 +517,9 @@ class CI_Input {
 					if ($separator === ':')
 					{
 						$netaddr = explode(':', str_replace('::', str_repeat(':', 9 - substr_count($netaddr, ':')), $netaddr));
-						for ($i = 0; $i < 8; $i++)
+						for ($j = 0; $j < 8; $j++)
 						{
-							$netaddr[$i] = intval($netaddr[$i], 16);
+							$netaddr[$j] = intval($netaddr[$j], 16);
 						}
 					}
 					else
@@ -760,30 +758,32 @@ class CI_Input {
 		// If header is already defined, return it immediately
 		if ( ! empty($this->headers))
 		{
-			return $this->headers;
+			return $this->_fetch_from_array($this->headers, NULL, $xss_clean);
 		}
 
 		// In Apache, you can simply call apache_request_headers()
 		if (function_exists('apache_request_headers'))
 		{
-			return $this->headers = apache_request_headers();
+			$this->headers = apache_request_headers();
 		}
-
-		$this->headers['Content-Type'] = isset($_SERVER['CONTENT_TYPE']) ? $_SERVER['CONTENT_TYPE'] : @getenv('CONTENT_TYPE');
-
-		foreach ($_SERVER as $key => $val)
+		else
 		{
-			if (sscanf($key, 'HTTP_%s', $header) === 1)
-			{
-				// take SOME_HEADER and turn it into Some-Header
-				$header = str_replace('_', ' ', strtolower($header));
-				$header = str_replace(' ', '-', ucwords($header));
+			isset($_SERVER['CONTENT_TYPE']) && $this->headers['Content-Type'] = $_SERVER['CONTENT_TYPE'];
 
-				$this->headers[$header] = $this->_fetch_from_array($_SERVER, $key, $xss_clean);
+			foreach ($_SERVER as $key => $val)
+			{
+				if (sscanf($key, 'HTTP_%s', $header) === 1)
+				{
+					// take SOME_HEADER and turn it into Some-Header
+					$header = str_replace('_', ' ', strtolower($header));
+					$header = str_replace(' ', '-', ucwords($header));
+
+					$this->headers[$header] = $_SERVER[$key];
+				}
 			}
 		}
 
-		return $this->headers;
+		return $this->_fetch_from_array($this->headers, NULL, $xss_clean);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/src/system/core/Lang.php b/src/system/core/Lang.php
index 1fcff078..569b0236 100644
--- a/src/system/core/Lang.php
+++ b/src/system/core/Lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/core/Loader.php b/src/system/core/Loader.php
index c742ae71..5ed6adb4 100644
--- a/src/system/core/Loader.php
+++ b/src/system/core/Loader.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -486,7 +486,7 @@ class CI_Loader {
 	 */
 	public function view($view, $vars = array(), $return = FALSE)
 	{
-		return $this->_ci_load(array('_ci_view' => $view, '_ci_vars' => $this->_ci_object_to_array($vars), '_ci_return' => $return));
+		return $this->_ci_load(array('_ci_view' => $view, '_ci_vars' => $this->_ci_prepare_view_vars($vars), '_ci_return' => $return));
 	}
 
 	// --------------------------------------------------------------------
@@ -519,19 +519,13 @@ class CI_Loader {
 	 */
 	public function vars($vars, $val = '')
 	{
-		if (is_string($vars))
-		{
-			$vars = array($vars => $val);
-		}
+		$vars = is_string($vars)
+			? array($vars => $val)
+			: $this->_ci_prepare_view_vars($vars);
 
-		$vars = $this->_ci_object_to_array($vars);
-
-		if (is_array($vars) && count($vars) > 0)
+		foreach ($vars as $key => $val)
 		{
-			foreach ($vars as $key => $val)
-			{
-				$this->_ci_cached_vars[$key] = $val;
-			}
+			$this->_ci_cached_vars[$key] = $val;
 		}
 
 		return $this;
@@ -591,15 +585,21 @@ class CI_Loader {
 	 */
 	public function helper($helpers = array())
 	{
-		foreach ($this->_ci_prep_filename($helpers, '_helper') as $helper)
+		is_array($helpers) OR $helpers = array($helpers);
+		foreach ($helpers as &$helper)
 		{
+			$filename = basename($helper);
+			$filepath = ($filename === $helper) ? '' : substr($helper, 0, strlen($helper) - strlen($filename));
+			$filename = strtolower(preg_replace('#(_helper)?(\.php)?$#i', '', $filename)).'_helper';
+			$helper   = $filepath.$filename;
+
 			if (isset($this->_ci_helpers[$helper]))
 			{
 				continue;
 			}
 
 			// Is this a helper extension request?
-			$ext_helper = config_item('subclass_prefix').$helper;
+			$ext_helper = config_item('subclass_prefix').$filename;
 			$ext_loaded = FALSE;
 			foreach ($this->_ci_helper_paths as $path)
 			{
@@ -934,18 +934,7 @@ class CI_Loader {
 		 * the two types and cache them so that views that are embedded within
 		 * other views can have access to these variables.
 		 */
-		if (is_array($_ci_vars))
-		{
-			foreach (array_keys($_ci_vars) as $key)
-			{
-				if (strncmp($key, '_ci_', 4) === 0)
-				{
-					unset($_ci_vars[$key]);
-				}
-			}
-
-			$this->_ci_cached_vars = array_merge($this->_ci_cached_vars, $_ci_vars);
-		}
+		empty($_ci_vars) OR $this->_ci_cached_vars = array_merge($this->_ci_cached_vars, $_ci_vars);
 		extract($this->_ci_cached_vars);
 
 		/*
@@ -1106,7 +1095,7 @@ class CI_Loader {
 	 * @used-by	CI_Loader::_ci_load_library()
 	 * @uses	CI_Loader::_ci_init_library()
 	 *
-	 * @param	string	$library	Library name to load
+	 * @param	string	$library_name	Library name to load
 	 * @param	string	$file_path	Path to the library filename, relative to libraries/
 	 * @param	mixed	$params		Optional parameters to pass to the class constructor
 	 * @param	string	$object_name	Optional object name to assign to
@@ -1376,17 +1365,32 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * CI Object to Array translator
+	 * Prepare variables for _ci_vars, to be later extract()-ed inside views
 	 *
-	 * Takes an object as input and converts the class variables to
-	 * an associative array with key/value pairs.
+	 * Converts objects to associative arrays and filters-out internal
+	 * variable names (i.e. keys prefixed with '_ci_').
 	 *
-	 * @param	object	$object	Object data to translate
+	 * @param	mixed	$vars
 	 * @return	array
 	 */
-	protected function _ci_object_to_array($object)
+	protected function _ci_prepare_view_vars($vars)
 	{
-		return is_object($object) ? get_object_vars($object) : $object;
+		if ( ! is_array($vars))
+		{
+			$vars = is_object($vars)
+				? get_object_vars($vars)
+				: array();
+		}
+
+		foreach (array_keys($vars) as $key)
+		{
+			if (strncmp($key, '_ci_', 4) === 0)
+			{
+				unset($vars[$key]);
+			}
+		}
+
+		return $vars;
 	}
 
 	// --------------------------------------------------------------------
@@ -1404,34 +1408,4 @@ class CI_Loader {
 		$CI =& get_instance();
 		return $CI->$component;
 	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Prep filename
-	 *
-	 * This function prepares filenames of various items to
-	 * make their loading more reliable.
-	 *
-	 * @param	string|string[]	$filename	Filename(s)
-	 * @param 	string		$extension	Filename extension
-	 * @return	array
-	 */
-	protected function _ci_prep_filename($filename, $extension)
-	{
-		if ( ! is_array($filename))
-		{
-			return array(strtolower(str_replace(array($extension, '.php'), '', $filename).$extension));
-		}
-		else
-		{
-			foreach ($filename as $key => $val)
-			{
-				$filename[$key] = strtolower(str_replace(array($extension, '.php'), '', $val).$extension);
-			}
-
-			return $filename;
-		}
-	}
-
 }
diff --git a/src/system/core/Log.php b/src/system/core/Log.php
index 1abdaa00..d443aedb 100644
--- a/src/system/core/Log.php
+++ b/src/system/core/Log.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -104,6 +104,13 @@ class CI_Log {
 	 */
 	protected $_levels = array('ERROR' => 1, 'DEBUG' => 2, 'INFO' => 3, 'ALL' => 4);
 
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_overload;
+
 	// --------------------------------------------------------------------
 
 	/**
@@ -115,6 +122,8 @@ class CI_Log {
 	{
 		$config =& get_config();
 
+		isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
+
 		$this->_log_path = ($config['log_path'] !== '') ? $config['log_path'] : APPPATH.'logs/';
 		$this->_file_ext = (isset($config['log_file_extension']) && $config['log_file_extension'] !== '')
 			? ltrim($config['log_file_extension'], '.') : 'php';
@@ -208,9 +217,9 @@ class CI_Log {
 
 		$message .= $this->_format_line($level, $date, $msg);
 
-		for ($written = 0, $length = strlen($message); $written < $length; $written += $result)
+		for ($written = 0, $length = self::strlen($message); $written < $length; $written += $result)
 		{
-			if (($result = fwrite($fp, substr($message, $written))) === FALSE)
+			if (($result = fwrite($fp, self::substr($message, $written))) === FALSE)
 			{
 				break;
 			}
@@ -237,11 +246,51 @@ class CI_Log {
 	 *
 	 * @param	string	$level 	The error level
 	 * @param	string	$date 	Formatted date string
-	 * @param	string	$msg 	The log message
+	 * @param	string	$message 	The log message
 	 * @return	string	Formatted log line with a new line character '\n' at the end
 	 */
 	protected function _format_line($level, $date, $message)
 	{
 		return $level.' - '.$date.' --> '.$message."\n";
 	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return (self::$func_overload)
+			? mb_strlen($str, '8bit')
+			: strlen($str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param	string	$str
+	 * @param	int	$start
+	 * @param	int	$length
+	 * @return	string
+	 */
+	protected static function substr($str, $start, $length = NULL)
+	{
+		if (self::$func_overload)
+		{
+			// mb_substr($str, $start, null, '8bit') returns an empty
+			// string on PHP 5.3
+			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length)
+			? substr($str, $start, $length)
+			: substr($str, $start);
+	}
 }
diff --git a/src/system/core/Model.php b/src/system/core/Model.php
index 941881a9..c809e7b8 100644
--- a/src/system/core/Model.php
+++ b/src/system/core/Model.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/core/Output.php b/src/system/core/Output.php
index ec9c21b9..6ddded22 100644
--- a/src/system/core/Output.php
+++ b/src/system/core/Output.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -122,6 +122,13 @@ class CI_Output {
 	 */
 	public $parse_exec_vars = TRUE;
 
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_overload;
+
 	/**
 	 * Class constructor
 	 *
@@ -138,6 +145,8 @@ class CI_Output {
 			&& extension_loaded('zlib')
 		);
 
+		isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
+
 		// Get mime types for later
 		$this->mimes =& get_mimes();
 
@@ -285,7 +294,7 @@ class CI_Output {
 	/**
 	 * Get Header
 	 *
-	 * @param	string	$header_name
+	 * @param	string	$header
 	 * @return	string
 	 */
 	public function get_header($header)
@@ -302,11 +311,12 @@ class CI_Output {
 			return NULL;
 		}
 
-		for ($i = 0, $c = count($headers); $i < $c; $i++)
+		// Count backwards, in order to get the last matching header
+		for ($c = count($headers) - 1; $c > -1; $c--)
 		{
-			if (strncasecmp($header, $headers[$i], $l = strlen($header)) === 0)
+			if (strncasecmp($header, $headers[$c], $l = self::strlen($header)) === 0)
 			{
-				return trim(substr($headers[$i], $l+1));
+				return trim(self::substr($headers[$c], $l+1));
 			}
 		}
 
@@ -480,13 +490,13 @@ class CI_Output {
 				if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE)
 				{
 					header('Content-Encoding: gzip');
-					header('Content-Length: '.strlen($output));
+					header('Content-Length: '.self::strlen($output));
 				}
 				else
 				{
 					// User agent doesn't support gzip compression,
 					// so we'll have to decompress our cache
-					$output = gzinflate(substr($output, 10, -8));
+					$output = gzinflate(self::substr($output, 10, -8));
 				}
 			}
 
@@ -601,9 +611,9 @@ class CI_Output {
 
 			$output = $cache_info.'ENDCI--->'.$output;
 
-			for ($written = 0, $length = strlen($output); $written < $length; $written += $result)
+			for ($written = 0, $length = self::strlen($output); $written < $length; $written += $result)
 			{
-				if (($result = fwrite($fp, substr($output, $written))) === FALSE)
+				if (($result = fwrite($fp, self::substr($output, $written))) === FALSE)
 				{
 					break;
 				}
@@ -711,7 +721,7 @@ class CI_Output {
 		}
 
 		// Display the cache
-		$this->_display(substr($cache, strlen($match[0])));
+		$this->_display(self::substr($cache, self::strlen($match[0])));
 		log_message('debug', 'Cache file is current. Sending it to browser.');
 		return TRUE;
 	}
@@ -797,4 +807,43 @@ class CI_Output {
 		}
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return (self::$func_overload)
+			? mb_strlen($str, '8bit')
+			: strlen($str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param	string	$str
+	 * @param	int	$start
+	 * @param	int	$length
+	 * @return	string
+	 */
+	protected static function substr($str, $start, $length = NULL)
+	{
+		if (self::$func_overload)
+		{
+			// mb_substr($str, $start, null, '8bit') returns an empty
+			// string on PHP 5.3
+			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length)
+			? substr($str, $start, $length)
+			: substr($str, $start);
+	}
 }
diff --git a/src/system/core/Router.php b/src/system/core/Router.php
index 045d3668..1abe4c4e 100644
--- a/src/system/core/Router.php
+++ b/src/system/core/Router.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/core/Security.php b/src/system/core/Security.php
index d5305d1c..082ffa96 100644
--- a/src/system/core/Security.php
+++ b/src/system/core/Security.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -133,15 +133,16 @@ class CI_Security {
 	 * @var	array
 	 */
 	protected $_never_allowed_str =	array(
-		'document.cookie'	=> '[removed]',
-		'document.write'	=> '[removed]',
-		'.parentNode'		=> '[removed]',
-		'.innerHTML'		=> '[removed]',
-		'-moz-binding'		=> '[removed]',
-		'<!--'				=> '&lt;!--',
-		'-->'				=> '--&gt;',
-		'<![CDATA['			=> '&lt;![CDATA[',
-		'<comment>'			=> '&lt;comment&gt;'
+		'document.cookie' => '[removed]',
+		'document.write'  => '[removed]',
+		'.parentNode'     => '[removed]',
+		'.innerHTML'      => '[removed]',
+		'-moz-binding'    => '[removed]',
+		'<!--'            => '&lt;!--',
+		'-->'             => '--&gt;',
+		'<![CDATA['       => '&lt;![CDATA[',
+		'<comment>'	  => '&lt;comment&gt;',
+		'<%'              => '&lt;&#37;'
 	);
 
 	/**
@@ -223,14 +224,11 @@ class CI_Security {
 			}
 		}
 
-		// Do the tokens exist in both the _POST and _COOKIE arrays?
-		if ( ! isset($_POST[$this->_csrf_token_name], $_COOKIE[$this->_csrf_cookie_name])
-			OR $_POST[$this->_csrf_token_name] !== $_COOKIE[$this->_csrf_cookie_name]) // Do the tokens match?
-		{
-			$this->csrf_show_error();
-		}
+		// Check CSRF token validity, but don't error on mismatch just yet - we'll want to regenerate
+		$valid = isset($_POST[$this->_csrf_token_name], $_COOKIE[$this->_csrf_cookie_name])
+			&& hash_equals($_POST[$this->_csrf_token_name], $_COOKIE[$this->_csrf_cookie_name]);
 
-		// We kill this since we're done and we don't want to polute the _POST array
+		// We kill this since we're done and we don't want to pollute the _POST array
 		unset($_POST[$this->_csrf_token_name]);
 
 		// Regenerate on every submission?
@@ -244,6 +242,11 @@ class CI_Security {
 		$this->_csrf_set_hash();
 		$this->csrf_set_cookie();
 
+		if ($valid !== TRUE)
+		{
+			$this->csrf_show_error();
+		}
+
 		log_message('info', 'CSRF token verified');
 		return $this;
 	}
@@ -351,9 +354,9 @@ class CI_Security {
 		// Is the string an array?
 		if (is_array($str))
 		{
-			while (list($key) = each($str))
+			foreach ($str as $key => &$value)
 			{
-				$str[$key] = $this->xss_clean($str[$key]);
+				$str[$key] = $this->xss_clean($value);
 			}
 
 			return $str;
@@ -371,11 +374,17 @@ class CI_Security {
 		 *
 		 * Note: Use rawurldecode() so it does not remove plus signs
 		 */
-		do
+		if (stripos($str, '%') !== false)
 		{
-			$str = rawurldecode($str);
+			do
+			{
+				$oldstr = $str;
+				$str = rawurldecode($str);
+				$str = preg_replace_callback('#%(?:\s*[0-9a-f]){2,}#i', array($this, '_urldecodespaces'), $str);
+			}
+			while ($oldstr !== $str);
+			unset($oldstr);
 		}
-		while (preg_match('/%[0-9a-f]{2,}/i', $str));
 
 		/*
 		 * Convert character entities to ASCII
@@ -466,7 +475,7 @@ class CI_Security {
 
 			if (preg_match('/<a/i', $str))
 			{
-				$str = preg_replace_callback('#<a[^a-z0-9>]+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
+				$str = preg_replace_callback('#<a(?:rea)?[^a-z0-9>]+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
 			}
 
 			if (preg_match('/<img/i', $str))
@@ -492,7 +501,7 @@ class CI_Security {
 		 * Becomes: &lt;blink&gt;
 		 */
 		$pattern = '#'
-			.'<((?<slash>/*\s*)(?<tagName>[a-z0-9]+)(?=[^a-z0-9]|$)' // tag start and name, followed by a non-tag character
+			.'<((?<slash>/*\s*)((?<tagName>[a-z0-9]+)(?=[^a-z0-9]|$)|.+)' // tag start and name, followed by a non-tag character
 			.'[^\s\042\047a-z0-9>/=]*' // a valid attribute character immediately after the tag would count as a separator
 			// optional attributes
 			.'(?<attributes>(?:[\s\042\047/=]*' // non-attribute characters, excluding > (tag close) for obvious reasons
@@ -669,6 +678,22 @@ class CI_Security {
 			? ENT_COMPAT | ENT_HTML5
 			: ENT_COMPAT;
 
+		if ( ! isset($_entities))
+		{
+			$_entities = array_map('strtolower', get_html_translation_table(HTML_ENTITIES, $flag, $charset));
+
+			// If we're not on PHP 5.4+, add the possibly dangerous HTML 5
+			// entities to the array manually
+			if ($flag === ENT_COMPAT)
+			{
+				$_entities[':'] = '&colon;';
+				$_entities['('] = '&lpar;';
+				$_entities[')'] = '&rpar;';
+				$_entities["\n"] = '&NewLine;';
+				$_entities["\t"] = '&Tab;';
+			}
+		}
+
 		do
 		{
 			$str_compare = $str;
@@ -676,27 +701,6 @@ class CI_Security {
 			// Decode standard entities, avoiding false positives
 			if (preg_match_all('/&[a-z]{2,}(?![a-z;])/i', $str, $matches))
 			{
-				if ( ! isset($_entities))
-				{
-					$_entities = array_map(
-						'strtolower',
-						is_php('5.3.4')
-							? get_html_translation_table(HTML_ENTITIES, $flag, $charset)
-							: get_html_translation_table(HTML_ENTITIES, $flag)
-					);
-
-					// If we're not on PHP 5.4+, add the possibly dangerous HTML 5
-					// entities to the array manually
-					if ($flag === ENT_COMPAT)
-					{
-						$_entities[':'] = '&colon;';
-						$_entities['('] = '&lpar;';
-						$_entities[')'] = '&rpar;';
-						$_entities["\n"] = '&newline;';
-						$_entities["\t"] = '&tab;';
-					}
-				}
-
 				$replace = array();
 				$matches = array_unique(array_map('strtolower', $matches[0]));
 				foreach ($matches as &$match)
@@ -707,7 +711,7 @@ class CI_Security {
 					}
 				}
 
-				$str = str_ireplace(array_keys($replace), array_values($replace), $str);
+				$str = str_replace(array_keys($replace), array_values($replace), $str);
 			}
 
 			// Decode numeric & UTF16 two byte entities
@@ -716,6 +720,11 @@ class CI_Security {
 				$flag,
 				$charset
 			);
+
+			if ($flag === ENT_COMPAT)
+			{
+				$str = str_replace(array_values($_entities), array_keys($_entities), $str);
+			}
 		}
 		while ($str_compare !== $str);
 		return $str;
@@ -774,6 +783,24 @@ class CI_Security {
 
 	// ----------------------------------------------------------------
 
+	/**
+	 * URL-decode taking spaces into account
+	 *
+	 * @see		https://github.com/bcit-ci/CodeIgniter/issues/4877
+	 * @param	array	$matches
+	 * @return	string
+	 */
+	protected function _urldecodespaces($matches)
+	{
+		$input    = $matches[0];
+		$nospaces = preg_replace('#\s+#', '', $input);
+		return ($nospaces === $input)
+			? $input
+			: rawurldecode($nospaces);
+	}
+
+	// ----------------------------------------------------------------
+
 	/**
 	 * Compact Exploded Words
 	 *
@@ -803,7 +830,7 @@ class CI_Security {
 	protected function _sanitize_naughty_html($matches)
 	{
 		static $naughty_tags    = array(
-			'alert', 'prompt', 'confirm', 'applet', 'audio', 'basefont', 'base', 'behavior', 'bgsound',
+			'alert', 'area', 'prompt', 'confirm', 'applet', 'audio', 'basefont', 'base', 'behavior', 'bgsound',
 			'blink', 'body', 'embed', 'expression', 'form', 'frameset', 'frame', 'head', 'html', 'ilayer',
 			'iframe', 'input', 'button', 'select', 'isindex', 'layer', 'link', 'meta', 'keygen', 'object',
 			'plaintext', 'style', 'script', 'textarea', 'title', 'math', 'video', 'svg', 'xml', 'xss'
@@ -842,7 +869,7 @@ class CI_Security {
 			// Each iteration filters a single attribute
 			do
 			{
-				// Strip any non-alpha characters that may preceed an attribute.
+				// Strip any non-alpha characters that may precede an attribute.
 				// Browsers often parse these incorrectly and that has been a
 				// of numerous XSS issues we've had.
 				$matches['attributes'] = preg_replace('#^[^a-z]+#i', '', $matches['attributes']);
@@ -900,7 +927,7 @@ class CI_Security {
 		return str_replace(
 			$match[1],
 			preg_replace(
-				'#href=.*?(?:(?:alert|prompt|confirm)(?:\(|&\#40;)|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|data\s*:)#si',
+				'#href=.*?(?:(?:alert|prompt|confirm)(?:\(|&\#40;)|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|d\s*a\s*t\s*a\s*:)#si',
 				'',
 				$this->_filter_attributes($match[1])
 			),
diff --git a/src/system/core/URI.php b/src/system/core/URI.php
index 544f6c85..3ccdfa7b 100644
--- a/src/system/core/URI.php
+++ b/src/system/core/URI.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/core/Utf8.php b/src/system/core/Utf8.php
index f2f42e6c..dfbbfff2 100644
--- a/src/system/core/Utf8.php
+++ b/src/system/core/Utf8.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.0
diff --git a/src/system/core/compat/hash.php b/src/system/core/compat/hash.php
index 6854e4c2..c65203aa 100644
--- a/src/system/core/compat/hash.php
+++ b/src/system/core/compat/hash.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -119,7 +119,7 @@ if ( ! function_exists('hash_pbkdf2'))
 	 */
 	function hash_pbkdf2($algo, $password, $salt, $iterations, $length = 0, $raw_output = FALSE)
 	{
-		if ( ! in_array($algo, hash_algos(), TRUE))
+		if ( ! in_array(strtolower($algo), hash_algos(), TRUE))
 		{
 			trigger_error('hash_pbkdf2(): Unknown hashing algorithm: '.$algo, E_USER_WARNING);
 			return FALSE;
@@ -173,7 +173,9 @@ if ( ! function_exists('hash_pbkdf2'))
 			return FALSE;
 		}
 
-		$hash_length = strlen(hash($algo, NULL, TRUE));
+		$hash_length = defined('MB_OVERLOAD_STRING')
+			? mb_strlen(hash($algo, NULL, TRUE), '8bit')
+			: strlen(hash($algo, NULL, TRUE));
 		empty($length) && $length = $hash_length;
 
 		// Pre-hash password inputs longer than the algorithm's block size
@@ -221,14 +223,14 @@ if ( ! function_exists('hash_pbkdf2'))
 			'whirlpool' => 64
 		);
 
-		if (isset($block_sizes[$algo]) && strlen($password) > $block_sizes[$algo])
+		if (isset($block_sizes[$algo], $password[$block_sizes[$algo]]))
 		{
 			$password = hash($algo, $password, TRUE);
 		}
 
 		$hash = '';
 		// Note: Blocks are NOT 0-indexed
-		for ($bc = ceil($length / $hash_length), $bi = 1; $bi <= $bc; $bi++)
+		for ($bc = (int) ceil($length / $hash_length), $bi = 1; $bi <= $bc; $bi++)
 		{
 			$key = $derived_key = hash_hmac($algo, $salt.pack('N', $bi), $password, TRUE);
 			for ($i = 1; $i < $iterations; $i++)
@@ -240,6 +242,13 @@ if ( ! function_exists('hash_pbkdf2'))
 		}
 
 		// This is not RFC-compatible, but we're aiming for natural PHP compatibility
-		return substr($raw_output ? $hash : bin2hex($hash), 0, $length);
+		if ( ! $raw_output)
+		{
+			$hash = bin2hex($hash);
+		}
+
+		return defined('MB_OVERLOAD_STRING')
+			? mb_substr($hash, 0, $length, '8bit')
+			: substr($hash, 0, $length);
 	}
 }
diff --git a/src/system/core/compat/mbstring.php b/src/system/core/compat/mbstring.php
index 554d1004..f466e1c3 100644
--- a/src/system/core/compat/mbstring.php
+++ b/src/system/core/compat/mbstring.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/core/compat/password.php b/src/system/core/compat/password.php
index f0c22c78..8176f008 100644
--- a/src/system/core/compat/password.php
+++ b/src/system/core/compat/password.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -50,7 +50,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 
 // ------------------------------------------------------------------------
 
-if (is_php('5.5') OR ! is_php('5.3.7') OR ! defined('CRYPT_BLOWFISH') OR CRYPT_BLOWFISH !== 1 OR defined('HHVM_VERSION'))
+if (is_php('5.5') OR ! defined('CRYPT_BLOWFISH') OR CRYPT_BLOWFISH !== 1 OR defined('HHVM_VERSION'))
 {
 	return;
 }
@@ -94,8 +94,8 @@ if ( ! function_exists('password_hash'))
 	 */
 	function password_hash($password, $algo, array $options = array())
 	{
-		static $func_override;
-		isset($func_override) OR $func_override = (extension_loaded('mbstring') && ini_get('mbstring.func_override'));
+		static $func_overload;
+		isset($func_overload) OR $func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
 
 		if ($algo !== 1)
 		{
@@ -109,21 +109,29 @@ if ( ! function_exists('password_hash'))
 			return NULL;
 		}
 
-		if (isset($options['salt']) && ($saltlen = ($func_override ? mb_strlen($options['salt'], '8bit') : strlen($options['salt']))) < 22)
+		if (isset($options['salt']) && ($saltlen = ($func_overload ? mb_strlen($options['salt'], '8bit') : strlen($options['salt']))) < 22)
 		{
 			trigger_error('password_hash(): Provided salt is too short: '.$saltlen.' expecting 22', E_USER_WARNING);
 			return NULL;
 		}
 		elseif ( ! isset($options['salt']))
 		{
-			if (defined('MCRYPT_DEV_URANDOM'))
+			if (function_exists('random_bytes'))
+			{
+				try
+				{
+					$options['salt'] = random_bytes(16);
+				}
+				catch (Exception $e)
+				{
+					log_message('error', 'compat/password: Error while trying to use random_bytes(): '.$e->getMessage());
+					return FALSE;
+				}
+			}
+			elseif (defined('MCRYPT_DEV_URANDOM'))
 			{
 				$options['salt'] = mcrypt_create_iv(16, MCRYPT_DEV_URANDOM);
 			}
-			elseif (function_exists('openssl_random_pseudo_bytes'))
-			{
-				$options['salt'] = openssl_random_pseudo_bytes(16);
-			}
 			elseif (DIRECTORY_SEPARATOR === '/' && (is_readable($dev = '/dev/arandom') OR is_readable($dev = '/dev/urandom')))
 			{
 				if (($fp = fopen($dev, 'rb')) === FALSE)
@@ -136,7 +144,7 @@ if ( ! function_exists('password_hash'))
 				is_php('5.4') && stream_set_chunk_size($fp, 16);
 
 				$options['salt'] = '';
-				for ($read = 0; $read < 16; $read = ($func_override) ? mb_strlen($options['salt'], '8bit') : strlen($options['salt']))
+				for ($read = 0; $read < 16; $read = ($func_overload) ? mb_strlen($options['salt'], '8bit') : strlen($options['salt']))
 				{
 					if (($read = fread($fp, 16 - $read)) === FALSE)
 					{
@@ -148,6 +156,16 @@ if ( ! function_exists('password_hash'))
 
 				fclose($fp);
 			}
+			elseif (function_exists('openssl_random_pseudo_bytes'))
+			{
+				$is_secure = NULL;
+				$options['salt'] = openssl_random_pseudo_bytes(16, $is_secure);
+				if ($is_secure !== TRUE)
+				{
+					log_message('error', 'compat/password: openssl_random_pseudo_bytes() set the $cryto_strong flag to FALSE');
+					return FALSE;
+				}
+			}
 			else
 			{
 				log_message('error', 'compat/password: No CSPRNG available.');
diff --git a/src/system/core/compat/standard.php b/src/system/core/compat/standard.php
index 47d47aef..7db2efb5 100644
--- a/src/system/core/compat/standard.php
+++ b/src/system/core/compat/standard.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -62,7 +62,7 @@ if ( ! function_exists('array_column'))
 	 * array_column()
 	 *
 	 * @link	http://php.net/array_column
-	 * @param	string	$array
+	 * @param	array	$array
 	 * @param	mixed	$column_key
 	 * @param	mixed	$index_key
 	 * @return	array
@@ -153,7 +153,7 @@ if ( ! function_exists('hex2bin'))
 	 */
 	function hex2bin($data)
 	{
-		if (in_array($type = gettype($data), array('array', 'double', 'object'), TRUE))
+		if (in_array($type = gettype($data), array('array', 'double', 'object', 'resource'), TRUE))
 		{
 			if ($type === 'object' && method_exists($data, '__toString'))
 			{
@@ -180,210 +180,3 @@ if ( ! function_exists('hex2bin'))
 		return pack('H*', $data);
 	}
 }
-
-// ------------------------------------------------------------------------
-
-if (is_php('5.3'))
-{
-	return;
-}
-
-// ------------------------------------------------------------------------
-
-if ( ! function_exists('array_replace'))
-{
-	/**
-	 * array_replace()
-	 *
-	 * @link	http://php.net/array_replace
-	 * @return	array
-	 */
-	function array_replace()
-	{
-		$arrays = func_get_args();
-
-		if (($c = count($arrays)) === 0)
-		{
-			trigger_error('array_replace() expects at least 1 parameter, 0 given', E_USER_WARNING);
-			return NULL;
-		}
-		elseif ($c === 1)
-		{
-			if ( ! is_array($arrays[0]))
-			{
-				trigger_error('array_replace(): Argument #1 is not an array', E_USER_WARNING);
-				return NULL;
-			}
-
-			return $arrays[0];
-		}
-
-		$array = array_shift($arrays);
-		$c--;
-
-		for ($i = 0; $i < $c; $i++)
-		{
-			if ( ! is_array($arrays[$i]))
-			{
-				trigger_error('array_replace(): Argument #'.($i + 2).' is not an array', E_USER_WARNING);
-				return NULL;
-			}
-			elseif (empty($arrays[$i]))
-			{
-				continue;
-			}
-
-			foreach (array_keys($arrays[$i]) as $key)
-			{
-				$array[$key] = $arrays[$i][$key];
-			}
-		}
-
-		return $array;
-	}
-}
-
-// ------------------------------------------------------------------------
-
-if ( ! function_exists('array_replace_recursive'))
-{
-	/**
-	 * array_replace_recursive()
-	 *
-	 * @link	http://php.net/array_replace_recursive
-	 * @return	array
-	 */
-	function array_replace_recursive()
-	{
-		$arrays = func_get_args();
-
-		if (($c = count($arrays)) === 0)
-		{
-			trigger_error('array_replace_recursive() expects at least 1 parameter, 0 given', E_USER_WARNING);
-			return NULL;
-		}
-		elseif ($c === 1)
-		{
-			if ( ! is_array($arrays[0]))
-			{
-				trigger_error('array_replace_recursive(): Argument #1 is not an array', E_USER_WARNING);
-				return NULL;
-			}
-
-			return $arrays[0];
-		}
-
-		$array = array_shift($arrays);
-		$c--;
-
-		for ($i = 0; $i < $c; $i++)
-		{
-			if ( ! is_array($arrays[$i]))
-			{
-				trigger_error('array_replace_recursive(): Argument #'.($i + 2).' is not an array', E_USER_WARNING);
-				return NULL;
-			}
-			elseif (empty($arrays[$i]))
-			{
-				continue;
-			}
-
-			foreach (array_keys($arrays[$i]) as $key)
-			{
-				$array[$key] = (is_array($arrays[$i][$key]) && isset($array[$key]) && is_array($array[$key]))
-					? array_replace_recursive($array[$key], $arrays[$i][$key])
-					: $arrays[$i][$key];
-			}
-		}
-
-		return $array;
-	}
-}
-
-// ------------------------------------------------------------------------
-
-if ( ! function_exists('quoted_printable_encode'))
-{
-	/**
-	 * quoted_printable_encode()
-	 *
-	 * @link	http://php.net/quoted_printable_encode
-	 * @param	string	$str
-	 * @return	string
-	 */
-	function quoted_printable_encode($str)
-	{
-		if (strlen($str) === 0)
-		{
-			return '';
-		}
-		elseif (in_array($type = gettype($str), array('array', 'object'), TRUE))
-		{
-			if ($type === 'object' && method_exists($str, '__toString'))
-			{
-				$str = (string) $str;
-			}
-			else
-			{
-				trigger_error('quoted_printable_encode() expects parameter 1 to be string, '.$type.' given', E_USER_WARNING);
-				return NULL;
-			}
-		}
-
-		if (function_exists('imap_8bit'))
-		{
-			return imap_8bit($str);
-		}
-
-		$i = $lp = 0;
-		$output = '';
-		$hex = '0123456789ABCDEF';
-		$length = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'))
-			? mb_strlen($str, '8bit')
-			: strlen($str);
-
-		while ($length--)
-		{
-			if ((($c = $str[$i++]) === "\015") && isset($str[$i]) && ($str[$i] === "\012") && $length > 0)
-			{
-				$output .= "\015".$str[$i++];
-				$length--;
-				$lp = 0;
-				continue;
-			}
-
-			if (
-				ctype_cntrl($c)
-				OR (ord($c) === 0x7f)
-				OR (ord($c) & 0x80)
-				OR ($c === '=')
-				OR ($c === ' ' && isset($str[$i]) && $str[$i] === "\015")
-			)
-			{
-				if (
-					(($lp += 3) > 75 && ord($c) <= 0x7f)
-					OR (ord($c) > 0x7f && ord($c) <= 0xdf && ($lp + 3) > 75)
-					OR (ord($c) > 0xdf && ord($c) <= 0xef && ($lp + 6) > 75)
-					OR (ord($c) > 0xef && ord($c) <= 0xf4 && ($lp + 9) > 75)
-				)
-				{
-					$output .= "=\015\012";
-					$lp = 3;
-				}
-
-				$output .= '='.$hex[ord($c) >> 4].$hex[ord($c) & 0xf];
-				continue;
-			}
-
-			if ((++$lp) > 75)
-			{
-				$output .= "=\015\012";
-				$lp = 1;
-			}
-
-			$output .= $c;
-		}
-
-		return $output;
-	}
-}
diff --git a/src/system/database/DB.php b/src/system/database/DB.php
index b4b7767e..c19eef72 100644
--- a/src/system/database/DB.php
+++ b/src/system/database/DB.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/database/DB_cache.php b/src/system/database/DB_cache.php
index 8855cc1b..b74c3192 100644
--- a/src/system/database/DB_cache.php
+++ b/src/system/database/DB_cache.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/database/DB_driver.php b/src/system/database/DB_driver.php
index 848516ad..3eb51f73 100644
--- a/src/system/database/DB_driver.php
+++ b/src/system/database/DB_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -980,7 +980,7 @@ abstract class CI_DB_driver {
 	 */
 	public function compile_binds($sql, $binds)
 	{
-		if (empty($binds) OR empty($this->bind_marker) OR strpos($sql, $this->bind_marker) === FALSE)
+		if (empty($this->bind_marker) OR strpos($sql, $this->bind_marker) === FALSE)
 		{
 			return $sql;
 		}
@@ -1000,7 +1000,7 @@ abstract class CI_DB_driver {
 		$ml = strlen($this->bind_marker);
 
 		// Make sure not to replace a chunk inside a string that happens to match the bind marker
-		if ($c = preg_match_all("/'[^']*'/i", $sql, $matches))
+		if ($c = preg_match_all("/'[^']*'|\"[^\"]*\"/i", $sql, $matches))
 		{
 			$c = preg_match_all('/'.preg_quote($this->bind_marker, '/').'/i',
 				str_replace($matches[0],
@@ -1173,14 +1173,14 @@ abstract class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
 	 */
 	protected function _escape_str($str)
 	{
-		return str_replace("'", "''", remove_invisible_characters($str));
+		return str_replace("'", "''", remove_invisible_characters($str, FALSE));
 	}
 
 	// --------------------------------------------------------------------
diff --git a/src/system/database/DB_forge.php b/src/system/database/DB_forge.php
index 826aa1eb..7289235c 100644
--- a/src/system/database/DB_forge.php
+++ b/src/system/database/DB_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -184,7 +184,7 @@ abstract class CI_DB_forge {
 		{
 			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
-		elseif ( ! $this->db->query(sprintf($this->_create_database, $db_name, $this->db->char_set, $this->db->dbcollat)))
+		elseif ( ! $this->db->query(sprintf($this->_create_database, $this->db->escape_identifiers($db_name), $this->db->char_set, $this->db->dbcollat)))
 		{
 			return ($this->db->db_debug) ? $this->db->display_error('db_unable_to_drop') : FALSE;
 		}
@@ -211,7 +211,7 @@ abstract class CI_DB_forge {
 		{
 			return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
 		}
-		elseif ( ! $this->db->query(sprintf($this->_drop_database, $db_name)))
+		elseif ( ! $this->db->query(sprintf($this->_drop_database, $this->db->escape_identifiers($db_name))))
 		{
 			return ($this->db->db_debug) ? $this->db->display_error('db_unable_to_drop') : FALSE;
 		}
@@ -348,7 +348,7 @@ abstract class CI_DB_forge {
 
 		if (($result = $this->db->query($sql)) !== FALSE)
 		{
-			empty($this->db->data_cache['table_names']) OR $this->db->data_cache['table_names'][] = $table;
+			isset($this->db->data_cache['table_names']) && $this->db->data_cache['table_names'][] = $table;
 
 			// Most databases don't support creating indexes from within the CREATE TABLE statement
 			if ( ! empty($this->keys))
diff --git a/src/system/database/DB_query_builder.php b/src/system/database/DB_query_builder.php
index c862d937..0abf2a26 100644
--- a/src/system/database/DB_query_builder.php
+++ b/src/system/database/DB_query_builder.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -149,6 +149,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected $qb_set			= array();
 
+	/**
+	 * QB data set for update_batch()
+	 *
+	 * @var	array
+	 */
+	protected $qb_set_ub			= array();
+
 	/**
 	 * QB aliased tables list
 	 *
@@ -207,6 +214,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected $qb_cache_join			= array();
 
+	/**
+	 * QB Cache aliased tables list
+	 *
+	 * @var	array
+	 */
+	protected $qb_cache_aliased_tables			= array();
+
 	/**
 	 * QB Cache WHERE data
 	 *
@@ -679,7 +693,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				// value appears not to have been set, assign the test to IS NULL
 				$k .= ' IS NULL';
 			}
-			elseif (preg_match('/\s*(!?=|<>|IS(?:\s+NOT)?)\s*$/i', $k, $match, PREG_OFFSET_CAPTURE))
+			elseif (preg_match('/\s*(!?=|<>|\sIS(?:\s+NOT)?\s)\s*$/i', $k, $match, PREG_OFFSET_CAPTURE))
 			{
 				$k = substr($k, 0, $match[0][1]).($match[1][0] === '=' ? ' IS NULL' : ' IS NOT NULL');
 			}
@@ -1271,7 +1285,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.($this->qb_offset ? $this->qb_offset.', ' : '').$this->qb_limit;
+		return $sql.' LIMIT '.($this->qb_offset ? $this->qb_offset.', ' : '').(int) $this->qb_limit;
 	}
 
 	// --------------------------------------------------------------------
@@ -1395,7 +1409,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$this->qb_orderby = NULL;
 		}
 
-		$result = ($this->qb_distinct === TRUE)
+		$result = ($this->qb_distinct === TRUE OR ! empty($this->qb_groupby) OR ! empty($this->qb_cache_groupby))
 			? $this->query($this->_count_string.$this->protect_identifiers('numrows')."\nFROM (\n".$this->_compile_select()."\n) CI_count_all_results")
 			: $this->query($this->_compile_select($this->_count_string.$this->protect_identifiers('numrows')));
 
@@ -1498,8 +1512,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		$affected_rows = 0;
 		for ($i = 0, $total = count($this->qb_set); $i < $total; $i += $batch_size)
 		{
-			$this->query($this->_insert_batch($this->protect_identifiers($table, TRUE, $escape, FALSE), $this->qb_keys, array_slice($this->qb_set, $i, $batch_size)));
-			$affected_rows += $this->affected_rows();
+			if ($this->query($this->_insert_batch($this->protect_identifiers($table, TRUE, $escape, FALSE), $this->qb_keys, array_slice($this->qb_set, $i, $batch_size))))
+			{
+				$affected_rows += $this->affected_rows();
+			}
 		}
 
 		$this->_reset_write();
@@ -1544,7 +1560,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
-		$keys = array_keys($this->_object_to_array(current($key)));
+		$keys = array_keys($this->_object_to_array(reset($key)));
 		sort($keys);
 
 		foreach ($key as $row)
@@ -1884,7 +1900,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		if ($set === NULL)
 		{
-			if (empty($this->qb_set))
+			if (empty($this->qb_set_ub))
 			{
 				return ($this->db_debug) ? $this->display_error('db_must_use_set') : FALSE;
 			}
@@ -1911,10 +1927,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		// Batch this baby
 		$affected_rows = 0;
-		for ($i = 0, $total = count($this->qb_set); $i < $total; $i += $batch_size)
+		for ($i = 0, $total = count($this->qb_set_ub); $i < $total; $i += $batch_size)
 		{
-			$this->query($this->_update_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), array_slice($this->qb_set, $i, $batch_size), $this->protect_identifiers($index)));
-			$affected_rows += $this->affected_rows();
+			if ($this->query($this->_update_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), array_slice($this->qb_set_ub, $i, $batch_size), $index)))
+			{
+				$affected_rows += $this->affected_rows();
+			}
+
 			$this->qb_where = array();
 		}
 
@@ -1939,13 +1958,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		$ids = array();
 		foreach ($values as $key => $val)
 		{
-			$ids[] = $val[$index];
+			$ids[] = $val[$index]['value'];
 
 			foreach (array_keys($val) as $field)
 			{
 				if ($field !== $index)
 				{
-					$final[$field][] = 'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
+					$final[$val[$field]['field']][] = 'WHEN '.$val[$index]['field'].' = '.$val[$index]['value'].' THEN '.$val[$field]['value'];
 				}
 			}
 		}
@@ -1958,7 +1977,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				.'ELSE '.$k.' END, ';
 		}
 
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+		$this->where($val[$index]['field'].' IN('.implode(',', $ids).')', NULL, FALSE);
 
 		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
@@ -1995,7 +2014,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 					$index_set = TRUE;
 				}
 
-				$clean[$this->protect_identifiers($k2, FALSE, $escape)] = ($escape === FALSE) ? $v2 : $this->escape($v2);
+				$clean[$k2] = array(
+					'field'  => $this->protect_identifiers($k2, FALSE, $escape),
+					'value'  => ($escape === FALSE ? $v2 : $this->escape($v2))
+				);
 			}
 
 			if ($index_set === FALSE)
@@ -2003,7 +2025,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				return $this->display_error('db_batch_missing_index');
 			}
 
-			$this->qb_set[] = $clean;
+			$this->qb_set_ub[] = $clean;
 		}
 
 		return $this;
@@ -2266,9 +2288,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$table = trim(strrchr($table, ' '));
 
 			// Store the alias, if it doesn't already exist
-			if ( ! in_array($table, $this->qb_aliased_tables))
+			if ( ! in_array($table, $this->qb_aliased_tables, TRUE))
 			{
 				$this->qb_aliased_tables[] = $table;
+				if ($this->qb_caching === TRUE && ! in_array($table, $this->qb_cache_aliased_tables, TRUE))
+				{
+					$this->qb_cache_aliased_tables[] = $table;
+					$this->qb_cache_exists[] = 'aliased_tables';
+				}
 			}
 		}
 	}
@@ -2335,7 +2362,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			.$this->_compile_order_by(); // ORDER BY
 
 		// LIMIT
-		if ($this->qb_limit)
+		if ($this->qb_limit OR $this->qb_offset)
 		{
 			return $this->_limit($sql."\n");
 		}
@@ -2426,7 +2453,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Escapes identifiers in GROUP BY statements at execution time.
 	 *
-	 * Required so that aliases are tracked properly, regardless of wether
+	 * Required so that aliases are tracked properly, regardless of whether
 	 * group_by() is called prior to from(), join() and dbprefix is added
 	 * only if needed.
 	 *
@@ -2462,7 +2489,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Escapes identifiers in ORDER BY statements at execution time.
 	 *
-	 * Required so that aliases are tracked properly, regardless of wether
+	 * Required so that aliases are tracked properly, regardless of whether
 	 * order_by() is called prior to from(), join() and dbprefix is added
 	 * only if needed.
 	 *
@@ -2470,26 +2497,27 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected function _compile_order_by()
 	{
-		if (is_array($this->qb_orderby) && count($this->qb_orderby) > 0)
+		if (empty($this->qb_orderby))
 		{
-			for ($i = 0, $c = count($this->qb_orderby); $i < $c; $i++)
-			{
-				if ($this->qb_orderby[$i]['escape'] !== FALSE && ! $this->_is_literal($this->qb_orderby[$i]['field']))
-				{
-					$this->qb_orderby[$i]['field'] = $this->protect_identifiers($this->qb_orderby[$i]['field']);
-				}
+			return '';
+		}
 
-				$this->qb_orderby[$i] = $this->qb_orderby[$i]['field'].$this->qb_orderby[$i]['direction'];
+		for ($i = 0, $c = count($this->qb_orderby); $i < $c; $i++)
+		{
+			if (is_string($this->qb_orderby[$i]))
+			{
+				continue;
 			}
 
-			return $this->qb_orderby = "\nORDER BY ".implode(', ', $this->qb_orderby);
-		}
-		elseif (is_string($this->qb_orderby))
-		{
-			return $this->qb_orderby;
+			if ($this->qb_orderby[$i]['escape'] !== FALSE && ! $this->_is_literal($this->qb_orderby[$i]['field']))
+			{
+				$this->qb_orderby[$i]['field'] = $this->protect_identifiers($this->qb_orderby[$i]['field']);
+			}
+
+			$this->qb_orderby[$i] = $this->qb_orderby[$i]['field'].$this->qb_orderby[$i]['direction'];
 		}
 
-		return '';
+		return "\nORDER BY ".implode(', ', $this->qb_orderby);
 	}
 
 	// --------------------------------------------------------------------
@@ -2610,7 +2638,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			'qb_cache_orderby'		=> array(),
 			'qb_cache_set'			=> array(),
 			'qb_cache_exists'		=> array(),
-			'qb_cache_no_escape'	=> array()
+			'qb_cache_no_escape'	=> array(),
+			'qb_cache_aliased_tables'	=> array()
 		));
 
 		return $this;
@@ -2661,13 +2690,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				$this->qb_no_escape = $qb_no_escape;
 			}
 		}
-
-		// If we are "protecting identifiers" we need to examine the "from"
-		// portion of the query to determine if there are any aliases
-		if ($this->_protect_identifiers === TRUE && count($this->qb_cache_from) > 0)
-		{
-			$this->_track_aliases($this->qb_from);
-		}
 	}
 
 	// --------------------------------------------------------------------
@@ -2770,6 +2792,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	{
 		$this->_reset_run(array(
 			'qb_set'	=> array(),
+			'qb_set_ub'	=> array(),
 			'qb_from'	=> array(),
 			'qb_join'	=> array(),
 			'qb_where'	=> array(),
diff --git a/src/system/database/DB_result.php b/src/system/database/DB_result.php
index d9d1fccc..98d8876a 100644
--- a/src/system/database/DB_result.php
+++ b/src/system/database/DB_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -660,7 +660,7 @@ class CI_DB_result {
 	 */
 	protected function _fetch_object($class_name = 'stdClass')
 	{
-		return array();
+		return new $class_name();
 	}
 
 }
diff --git a/src/system/database/DB_utility.php b/src/system/database/DB_utility.php
index 70528286..25d842c0 100644
--- a/src/system/database/DB_utility.php
+++ b/src/system/database/DB_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/database/drivers/cubrid/cubrid_driver.php b/src/system/database/drivers/cubrid/cubrid_driver.php
index 77f591ce..6e8aff7c 100644
--- a/src/system/database/drivers/cubrid/cubrid_driver.php
+++ b/src/system/database/drivers/cubrid/cubrid_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
@@ -250,7 +250,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -361,7 +361,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/src/system/database/drivers/cubrid/cubrid_forge.php b/src/system/database/drivers/cubrid/cubrid_forge.php
index 8262beb6..27bfc146 100644
--- a/src/system/database/drivers/cubrid/cubrid_forge.php
+++ b/src/system/database/drivers/cubrid/cubrid_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
@@ -178,6 +178,9 @@ class CI_DB_cubrid_forge extends CI_DB_forge {
 				$attributes['TYPE'] = 'INTEGER';
 				$attributes['UNSIGNED'] = FALSE;
 				return;
+			case 'LONGTEXT':
+				$attributes['TYPE'] = 'STRING';
+				return;
 			default: return;
 		}
 	}
diff --git a/src/system/database/drivers/cubrid/cubrid_result.php b/src/system/database/drivers/cubrid/cubrid_result.php
index 9cccb257..251b70a6 100644
--- a/src/system/database/drivers/cubrid/cubrid_result.php
+++ b/src/system/database/drivers/cubrid/cubrid_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
diff --git a/src/system/database/drivers/cubrid/cubrid_utility.php b/src/system/database/drivers/cubrid/cubrid_utility.php
index 942fa3b4..555ae7a9 100644
--- a/src/system/database/drivers/cubrid/cubrid_utility.php
+++ b/src/system/database/drivers/cubrid/cubrid_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
diff --git a/src/system/database/drivers/ibase/ibase_driver.php b/src/system/database/drivers/ibase/ibase_driver.php
index c1055c1e..3069d669 100644
--- a/src/system/database/drivers/ibase/ibase_driver.php
+++ b/src/system/database/drivers/ibase/ibase_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -294,7 +294,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -383,6 +383,23 @@ class CI_DB_ibase_driver extends CI_DB {
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * Insert batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data.
+	 *
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
+	 * @return	string|bool
+	 */
+	protected function _insert_batch($table, $keys, $values)
+	{
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Close DB Connection
 	 *
diff --git a/src/system/database/drivers/ibase/ibase_forge.php b/src/system/database/drivers/ibase/ibase_forge.php
index 9c358c36..44bb24e6 100644
--- a/src/system/database/drivers/ibase/ibase_forge.php
+++ b/src/system/database/drivers/ibase/ibase_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -111,7 +111,7 @@ class CI_DB_ibase_forge extends CI_DB_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		if ( ! ibase_drop_db($this->conn_id))
 		{
diff --git a/src/system/database/drivers/ibase/ibase_result.php b/src/system/database/drivers/ibase/ibase_result.php
index f3c21fce..7d7dd79a 100644
--- a/src/system/database/drivers/ibase/ibase_result.php
+++ b/src/system/database/drivers/ibase/ibase_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/ibase/ibase_utility.php b/src/system/database/drivers/ibase/ibase_utility.php
index 619ebad0..3c152101 100644
--- a/src/system/database/drivers/ibase/ibase_utility.php
+++ b/src/system/database/drivers/ibase/ibase_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/mssql/mssql_driver.php b/src/system/database/drivers/mssql/mssql_driver.php
index d40d67a0..a2ccd1c8 100644
--- a/src/system/database/drivers/mssql/mssql_driver.php
+++ b/src/system/database/drivers/mssql/mssql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
@@ -158,6 +158,7 @@ class CI_DB_mssql_driver extends CI_DB {
 		if (mssql_select_db('['.$database.']', $this->conn_id))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -351,7 +352,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -499,7 +500,7 @@ class CI_DB_mssql_driver extends CI_DB {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/src/system/database/drivers/mssql/mssql_forge.php b/src/system/database/drivers/mssql/mssql_forge.php
index 24d1fc20..6b610986 100644
--- a/src/system/database/drivers/mssql/mssql_forge.php
+++ b/src/system/database/drivers/mssql/mssql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
@@ -113,6 +113,11 @@ class CI_DB_mssql_forge extends CI_DB_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/src/system/database/drivers/mssql/mssql_result.php b/src/system/database/drivers/mssql/mssql_result.php
index b62bf75c..38a0a057 100644
--- a/src/system/database/drivers/mssql/mssql_result.php
+++ b/src/system/database/drivers/mssql/mssql_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/mssql/mssql_utility.php b/src/system/database/drivers/mssql/mssql_utility.php
index cd23be82..95ce88f1 100644
--- a/src/system/database/drivers/mssql/mssql_utility.php
+++ b/src/system/database/drivers/mssql/mssql_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/mysql/mysql_driver.php b/src/system/database/drivers/mysql/mysql_driver.php
index 78b1d703..71dad676 100644
--- a/src/system/database/drivers/mysql/mysql_driver.php
+++ b/src/system/database/drivers/mysql/mysql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -208,6 +208,7 @@ class CI_DB_mysql_driver extends CI_DB {
 		if (mysql_select_db($database, $this->conn_id))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -336,7 +337,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -447,7 +448,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/src/system/database/drivers/mysql/mysql_forge.php b/src/system/database/drivers/mysql/mysql_forge.php
index fa84be37..7ed8f8d3 100644
--- a/src/system/database/drivers/mysql/mysql_forge.php
+++ b/src/system/database/drivers/mysql/mysql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/database/drivers/mysql/mysql_result.php b/src/system/database/drivers/mysql/mysql_result.php
index 20cade2e..7aa265eb 100644
--- a/src/system/database/drivers/mysql/mysql_result.php
+++ b/src/system/database/drivers/mysql/mysql_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/database/drivers/mysql/mysql_utility.php b/src/system/database/drivers/mysql/mysql_utility.php
index 4c1f2391..bc01fc58 100644
--- a/src/system/database/drivers/mysql/mysql_utility.php
+++ b/src/system/database/drivers/mysql/mysql_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/database/drivers/mysqli/mysqli_driver.php b/src/system/database/drivers/mysqli/mysqli_driver.php
index 06c34187..b59e8949 100644
--- a/src/system/database/drivers/mysqli/mysqli_driver.php
+++ b/src/system/database/drivers/mysqli/mysqli_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
@@ -125,8 +125,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 		}
 		else
 		{
-			// Persistent connection support was added in PHP 5.3.0
-			$hostname = ($persistent === TRUE && is_php('5.3'))
+			$hostname = ($persistent === TRUE)
 				? 'p:'.$this->hostname : $this->hostname;
 			$port = empty($this->port) ? NULL : $this->port;
 			$socket = NULL;
@@ -184,7 +183,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 					// https://bugs.php.net/bug.php?id=68344
 					elseif (defined('MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT'))
 					{
-						$this->_mysqli->options(MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT, TRUE);
+						$client_flags |= MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT;
 					}
 				}
 
@@ -211,7 +210,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 				$this->_mysqli->close();
 				$message = 'MySQLi was configured for an SSL connection, but got an unencrypted connection instead!';
 				log_message('error', $message);
-				return ($this->db->db_debug) ? $this->db->display_error($message, '', TRUE) : FALSE;
+				return ($this->db_debug) ? $this->display_error($message, '', TRUE) : FALSE;
 			}
 
 			return $this->_mysqli;
@@ -256,6 +255,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 		if ($this->conn_id->select_db($database))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -381,7 +381,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -501,8 +501,8 @@ class CI_DB_mysqli_driver extends CI_DB {
 		if ( ! empty($this->_mysqli->connect_errno))
 		{
 			return array(
-				'code' => $this->_mysqli->connect_errno,
-				'message' => is_php('5.2.9') ? $this->_mysqli->connect_error : mysqli_connect_error()
+				'code'    => $this->_mysqli->connect_errno,
+				'message' => $this->_mysqli->connect_error
 			);
 		}
 
diff --git a/src/system/database/drivers/mysqli/mysqli_forge.php b/src/system/database/drivers/mysqli/mysqli_forge.php
index c17f729c..c5b23b6c 100644
--- a/src/system/database/drivers/mysqli/mysqli_forge.php
+++ b/src/system/database/drivers/mysqli/mysqli_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/mysqli/mysqli_result.php b/src/system/database/drivers/mysqli/mysqli_result.php
index 0ce07414..929c2b45 100644
--- a/src/system/database/drivers/mysqli/mysqli_result.php
+++ b/src/system/database/drivers/mysqli/mysqli_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/mysqli/mysqli_utility.php b/src/system/database/drivers/mysqli/mysqli_utility.php
index 79d9f367..4a3dad4d 100644
--- a/src/system/database/drivers/mysqli/mysqli_utility.php
+++ b/src/system/database/drivers/mysqli/mysqli_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/oci8/oci8_driver.php b/src/system/database/drivers/oci8/oci8_driver.php
index 59f0e845..fb2f6b31 100644
--- a/src/system/database/drivers/oci8/oci8_driver.php
+++ b/src/system/database/drivers/oci8/oci8_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.4.1
@@ -386,7 +386,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _trans_begin()
 	{
-		$this->commit_mode = is_php('5.3.2') ? OCI_NO_AUTO_COMMIT : OCI_DEFAULT;
+		$this->commit_mode = OCI_NO_AUTO_COMMIT;
 		return TRUE;
 	}
 
@@ -553,29 +553,35 @@ class CI_DB_oci8_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
 	public function error()
 	{
-		/* oci_error() returns an array that already contains the
-		 * 'code' and 'message' keys, so we can just return it.
-		 */
+		// oci_error() returns an array that already contains
+		// 'code' and 'message' keys, but it can return false
+		// if there was no error ....
 		if (is_resource($this->curs_id))
 		{
-			return oci_error($this->curs_id);
+			$error = oci_error($this->curs_id);
 		}
 		elseif (is_resource($this->stmt_id))
 		{
-			return oci_error($this->stmt_id);
+			$error = oci_error($this->stmt_id);
 		}
 		elseif (is_resource($this->conn_id))
 		{
-			return oci_error($this->conn_id);
+			$error = oci_error($this->conn_id);
+		}
+		else
+		{
+			$error = oci_error();
 		}
 
-		return oci_error();
+		return is_array($error)
+			? $error
+			: array('code' => '', 'message' => '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/src/system/database/drivers/oci8/oci8_forge.php b/src/system/database/drivers/oci8/oci8_forge.php
index 1ca559a3..867a9434 100644
--- a/src/system/database/drivers/oci8/oci8_forge.php
+++ b/src/system/database/drivers/oci8/oci8_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.4.1
@@ -53,6 +53,13 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 	 */
 	protected $_create_database	= FALSE;
 
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= FALSE;
+
 	/**
 	 * DROP DATABASE statement
 	 *
@@ -119,6 +126,8 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
 						.' '.$this->db->escape_identifiers($field[$i]['new_name']);
 				}
+
+				$field[$i] = "\n\t".$field[$i]['_literal'];
 			}
 		}
 
@@ -129,7 +138,7 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 
 		// RENAME COLUMN must be executed after MODIFY
 		array_unshift($sqls, $sql);
-		return $sql;
+		return $sqls;
 	}
 
 	// --------------------------------------------------------------------
@@ -146,4 +155,33 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 		// Not supported - sequences and triggers must be used instead
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'INT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'BIGINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			default: return;
+		}
+	}
 }
diff --git a/src/system/database/drivers/oci8/oci8_result.php b/src/system/database/drivers/oci8/oci8_result.php
index fc860ea1..0c354333 100644
--- a/src/system/database/drivers/oci8/oci8_result.php
+++ b/src/system/database/drivers/oci8/oci8_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.4.1
diff --git a/src/system/database/drivers/oci8/oci8_utility.php b/src/system/database/drivers/oci8/oci8_utility.php
index ebe49c46..ce0dfc5f 100644
--- a/src/system/database/drivers/oci8/oci8_utility.php
+++ b/src/system/database/drivers/oci8/oci8_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.4.1
diff --git a/src/system/database/drivers/odbc/odbc_driver.php b/src/system/database/drivers/odbc/odbc_driver.php
index 19b7b744..ef982fc6 100644
--- a/src/system/database/drivers/odbc/odbc_driver.php
+++ b/src/system/database/drivers/odbc/odbc_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
@@ -50,7 +50,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @author		EllisLab Dev Team
  * @link		https://codeigniter.com/user_guide/database/
  */
-class CI_DB_odbc_driver extends CI_DB {
+class CI_DB_odbc_driver extends CI_DB_driver {
 
 	/**
 	 * Database driver
@@ -93,6 +93,22 @@ class CI_DB_odbc_driver extends CI_DB {
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * ODBC result ID resource returned from odbc_prepare()
+	 *
+	 * @var	resource
+	 */
+	private $odbc_result;
+
+	/**
+	 * Values to use with odbc_execute() for prepared statements
+	 *
+	 * @var	array
+	 */
+	private $binds = array();
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Class constructor
 	 *
@@ -127,6 +143,74 @@ class CI_DB_odbc_driver extends CI_DB {
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * Compile Bindings
+	 *
+	 * @param	string	$sql	SQL statement
+	 * @param	array	$binds	An array of values to bind
+	 * @return	string
+	 */
+	public function compile_binds($sql, $binds)
+	{
+		if (empty($binds) OR empty($this->bind_marker) OR strpos($sql, $this->bind_marker) === FALSE)
+		{
+			return $sql;
+		}
+		elseif ( ! is_array($binds))
+		{
+			$binds = array($binds);
+			$bind_count = 1;
+		}
+		else
+		{
+			// Make sure we're using numeric keys
+			$binds = array_values($binds);
+			$bind_count = count($binds);
+		}
+
+		// We'll need the marker length later
+		$ml = strlen($this->bind_marker);
+
+		// Make sure not to replace a chunk inside a string that happens to match the bind marker
+		if ($c = preg_match_all("/'[^']*'|\"[^\"]*\"/i", $sql, $matches))
+		{
+			$c = preg_match_all('/'.preg_quote($this->bind_marker, '/').'/i',
+				str_replace($matches[0],
+					str_replace($this->bind_marker, str_repeat(' ', $ml), $matches[0]),
+					$sql, $c),
+				$matches, PREG_OFFSET_CAPTURE);
+
+			// Bind values' count must match the count of markers in the query
+			if ($bind_count !== $c)
+			{
+				return $sql;
+			}
+		}
+		elseif (($c = preg_match_all('/'.preg_quote($this->bind_marker, '/').'/i', $sql, $matches, PREG_OFFSET_CAPTURE)) !== $bind_count)
+		{
+			return $sql;
+		}
+
+		if ($this->bind_marker !== '?')
+		{
+			do
+			{
+				$c--;
+				$sql = substr_replace($sql, '?', $matches[0][$c][1], $ml);
+			}
+			while ($c !== 0);
+		}
+
+		if (FALSE !== ($this->odbc_result = odbc_prepare($this->conn_id, $sql)))
+		{
+			$this->binds = array_values($binds);
+		}
+
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Execute the query
 	 *
@@ -135,7 +219,25 @@ class CI_DB_odbc_driver extends CI_DB {
 	 */
 	protected function _execute($sql)
 	{
-		return odbc_exec($this->conn_id, $sql);
+		if ( ! isset($this->odbc_result))
+		{
+			return odbc_exec($this->conn_id, $sql);
+		}
+		elseif ($this->odbc_result === FALSE)
+		{
+			return FALSE;
+		}
+
+		if (TRUE === ($success = odbc_execute($this->odbc_result, $this->binds)))
+		{
+			// For queries that return result sets, return the result_id resource on success
+			$this->is_write_type($sql) OR $success = $this->odbc_result;
+		}
+
+		$this->odbc_result = NULL;
+		$this->binds       = array();
+
+		return $success;
 	}
 
 	// --------------------------------------------------------------------
@@ -196,7 +298,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 */
 	public function is_write_type($sql)
 	{
-		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#i', $sql))
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
 		{
 			return FALSE;
 		}
@@ -207,14 +309,14 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
 	 */
 	protected function _escape_str($str)
 	{
-		return remove_invisible_characters($str);
+		$this->display_error('db_unsupported_feature');
 	}
 
 	// --------------------------------------------------------------------
@@ -238,7 +340,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 */
 	public function insert_id()
 	{
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -300,7 +402,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -311,58 +413,6 @@ class CI_DB_odbc_driver extends CI_DB {
 
 	// --------------------------------------------------------------------
 
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	$table
-	 * @param	array	$values
-	 * @return	string
-	 */
-	protected function _update($table, $values)
-	{
-		$this->qb_limit = FALSE;
-		$this->qb_orderby = array();
-		return parent::_update($table, $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 *
-	 * If the database does not support the TRUNCATE statement,
-	 * then this method maps to 'DELETE FROM table'
-	 *
-	 * @param	string	$table
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'DELETE FROM '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Delete statement
-	 *
-	 * Generates a platform-specific delete string from the supplied data
-	 *
-	 * @param	string	$table
-	 * @return	string
-	 */
-	protected function _delete($table)
-	{
-		$this->qb_limit = FALSE;
-		return parent::_delete($table);
-	}
-
-	// --------------------------------------------------------------------
-
 	/**
 	 * Close DB Connection
 	 *
@@ -372,5 +422,4 @@ class CI_DB_odbc_driver extends CI_DB {
 	{
 		odbc_close($this->conn_id);
 	}
-
 }
diff --git a/src/system/database/drivers/odbc/odbc_forge.php b/src/system/database/drivers/odbc/odbc_forge.php
index bac30bed..77b2fdf6 100644
--- a/src/system/database/drivers/odbc/odbc_forge.php
+++ b/src/system/database/drivers/odbc/odbc_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/odbc/odbc_result.php b/src/system/database/drivers/odbc/odbc_result.php
index 110d6ab0..845aa9c7 100644
--- a/src/system/database/drivers/odbc/odbc_result.php
+++ b/src/system/database/drivers/odbc/odbc_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/odbc/odbc_utility.php b/src/system/database/drivers/odbc/odbc_utility.php
index 2e344963..643f6ec0 100644
--- a/src/system/database/drivers/odbc/odbc_utility.php
+++ b/src/system/database/drivers/odbc/odbc_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/pdo/pdo_driver.php b/src/system/database/drivers/pdo/pdo_driver.php
index c6f84e0f..6afc999c 100644
--- a/src/system/database/drivers/pdo/pdo_driver.php
+++ b/src/system/database/drivers/pdo/pdo_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
@@ -126,7 +126,10 @@ class CI_DB_pdo_driver extends CI_DB {
 	 */
 	public function db_connect($persistent = FALSE)
 	{
-		$this->options[PDO::ATTR_PERSISTENT] = $persistent;
+		if ($persistent === TRUE)
+		{
+			$this->options[PDO::ATTR_PERSISTENT] = TRUE;
+		}
 
 		try
 		{
@@ -220,7 +223,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -282,7 +285,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -307,52 +310,6 @@ class CI_DB_pdo_driver extends CI_DB {
 
 	// --------------------------------------------------------------------
 
-	/**
-	 * Update_Batch statement
-	 *
-	 * Generates a platform-specific batch update string from the supplied data
-	 *
-	 * @param	string	$table	Table name
-	 * @param	array	$values	Update data
-	 * @param	string	$index	WHERE key
-	 * @return	string
-	 */
-	protected function _update_batch($table, $values, $index)
-	{
-		$ids = array();
-		foreach ($values as $key => $val)
-		{
-			$ids[] = $val[$index];
-
-			foreach (array_keys($val) as $field)
-			{
-				if ($field !== $index)
-				{
-					$final[$field][] = 'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
-				}
-			}
-		}
-
-		$cases = '';
-		foreach ($final as $k => $v)
-		{
-			$cases .= $k.' = CASE '."\n";
-
-			foreach ($v as $row)
-			{
-				$cases .= $row."\n";
-			}
-
-			$cases .= 'ELSE '.$k.' END, ';
-		}
-
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
-
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
-	}
-
-	// --------------------------------------------------------------------
-
 	/**
 	 * Truncate statement
 	 *
diff --git a/src/system/database/drivers/pdo/pdo_forge.php b/src/system/database/drivers/pdo/pdo_forge.php
index 2595f7b6..685b6776 100644
--- a/src/system/database/drivers/pdo/pdo_forge.php
+++ b/src/system/database/drivers/pdo/pdo_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
diff --git a/src/system/database/drivers/pdo/pdo_result.php b/src/system/database/drivers/pdo/pdo_result.php
index d1809bef..bbc2cdc5 100644
--- a/src/system/database/drivers/pdo/pdo_result.php
+++ b/src/system/database/drivers/pdo/pdo_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
diff --git a/src/system/database/drivers/pdo/pdo_utility.php b/src/system/database/drivers/pdo/pdo_utility.php
index 384661bf..5029cac9 100644
--- a/src/system/database/drivers/pdo/pdo_utility.php
+++ b/src/system/database/drivers/pdo/pdo_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.1.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
index 3dedfd9b..7eaeaa1f 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
index 41994f9d..3f636d3b 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_4d_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
index 83777980..fc49e0dd 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -170,47 +170,6 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 
 	// --------------------------------------------------------------------
 
-	/**
-	 * Update_Batch statement
-	 *
-	 * Generates a platform-specific batch update string from the supplied data
-	 *
-	 * @param	string	$table	Table name
-	 * @param	array	$values	Update data
-	 * @param	string	$index	WHERE key
-	 * @return	string
-	 */
-	protected function _update_batch($table, $values, $index)
-	{
-		$ids = array();
-		foreach ($values as $key => $val)
-		{
-			$ids[] = $val[$index];
-
-			foreach (array_keys($val) as $field)
-			{
-				if ($field !== $index)
-				{
-					$final[$field][] = 'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
-				}
-			}
-		}
-
-		$cases = '';
-		foreach ($final as $k => $v)
-		{
-			$cases .= $k." = CASE \n"
-				.implode("\n", $v)."\n"
-				.'ELSE '.$k.' END), ';
-		}
-
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
-
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
-	}
-
-	// --------------------------------------------------------------------
-
 	/**
 	 * Truncate statement
 	 *
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
index 5f854061..276cbb6b 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_cubrid_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -178,6 +178,9 @@ class CI_DB_pdo_cubrid_forge extends CI_DB_pdo_forge {
 				$attributes['TYPE'] = 'INTEGER';
 				$attributes['UNSIGNED'] = FALSE;
 				return;
+			case 'LONGTEXT':
+				$attributes['TYPE'] = 'STRING';
+				return;
 			default: return;
 		}
 	}
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index 84695ee9..08243232 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -126,7 +126,12 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 */
 	public function db_connect($persistent = FALSE)
 	{
-		$this->conn_id = parent::db_connect($persistent);
+		if ($persistent === TRUE)
+		{
+			log_message('debug', "dblib driver doesn't support persistent connections");
+		}
+
+		$this->conn_id = parent::db_connect(FALSE);
 
 		if ( ! is_object($this->conn_id))
 		{
@@ -326,7 +331,7 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 }
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
index d5dd9aad..d0cca38d 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_dblib_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -111,6 +111,11 @@ class CI_DB_pdo_dblib_forge extends CI_DB_pdo_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index 96dcc5ec..cb93f19b 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -260,4 +260,20 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 		return preg_replace('`SELECT`i', 'SELECT '.$select, $sql);
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data.
+	 *
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
+	 * @return	string|bool
+	 */
+	protected function _insert_batch($table, $keys, $values)
+	{
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
+	}
 }
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
index 256fa141..20c5a689 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_firebird_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -97,7 +97,7 @@ class CI_DB_pdo_firebird_forge extends CI_DB_pdo_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		if ( ! ibase_drop_db($this->conn_id))
 		{
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
index 2366c403..26b556a7 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
index a2dbfc25..4238ca08 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_ibm_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
index d40d17a8..050171f6 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
index 5af39b18..2ddc2a93 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_informix_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index 70f2bfd4..64b13d82 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -106,7 +106,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 			empty($this->database) OR $this->dsn .= ';dbname='.$this->database;
 			empty($this->char_set) OR $this->dsn .= ';charset='.$this->char_set;
 		}
-		elseif ( ! empty($this->char_set) && strpos($this->dsn, 'charset=', 6) === FALSE && is_php('5.3.6'))
+		elseif ( ! empty($this->char_set) && strpos($this->dsn, 'charset=', 6) === FALSE)
 		{
 			$this->dsn .= ';charset='.$this->char_set;
 		}
@@ -122,17 +122,6 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 */
 	public function db_connect($persistent = FALSE)
 	{
-		/* Prior to PHP 5.3.6, even if the charset was supplied in the DSN
-		 * on connect - it was ignored. This is a work-around for the issue.
-		 *
-		 * Reference: http://www.php.net/manual/en/ref.pdo-mysql.connection.php
-		 */
-		if ( ! is_php('5.3.6') && ! empty($this->char_set))
-		{
-			$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET NAMES '.$this->char_set
-				.(empty($this->dbcollat) ? '' : ' COLLATE '.$this->dbcollat);
-		}
-
 		if (isset($this->stricton))
 		{
 			if ($this->stricton)
@@ -169,8 +158,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 			$this->options[PDO::MYSQL_ATTR_COMPRESS] = TRUE;
 		}
 
-		// SSL support was added to PDO_MYSQL in PHP 5.3.7
-		if (is_array($this->encrypt) && is_php('5.3.7'))
+		if (is_array($this->encrypt))
 		{
 			$ssl = array();
 			empty($this->encrypt['ssl_key'])    OR $ssl[PDO::MYSQL_ATTR_SSL_KEY]    = $this->encrypt['ssl_key'];
@@ -194,7 +182,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 		{
 			$message = 'PDO_MYSQL was configured for an SSL connection, but got an unencrypted connection instead!';
 			log_message('error', $message);
-			return ($this->db->db_debug) ? $this->db->display_error($message, '', TRUE) : FALSE;
+			return ($this->db_debug) ? $this->display_error($message, '', TRUE) : FALSE;
 		}
 
 		return $pdo;
@@ -218,6 +206,56 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 		if (FALSE !== $this->simple_query('USE '.$this->escape_identifiers($database)))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 *
+	 * @return	bool
+	 */
+	protected function _trans_begin()
+	{
+		$this->conn_id->setAttribute(PDO::ATTR_AUTOCOMMIT, FALSE);
+		return $this->conn_id->beginTransaction();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @return	bool
+	 */
+	protected function _trans_commit()
+	{
+		if ($this->conn_id->commit())
+		{
+			$this->conn_id->setAttribute(PDO::ATTR_AUTOCOMMIT, TRUE);
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @return	bool
+	 */
+	protected function _trans_rollback()
+	{
+		if ($this->conn_id->rollBack())
+		{
+			$this->conn_id->setAttribute(PDO::ATTR_AUTOCOMMIT, TRUE);
 			return TRUE;
 		}
 
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
index 9d04a8a9..c7a92b82 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_mysql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
index dd1d31c2..abf9167d 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
index d0b7be8f..c8983ee5 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -53,6 +53,13 @@ class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
 	 */
 	protected $_create_database	= FALSE;
 
+	/**
+	 * CREATE TABLE IF statement
+	 *
+	 * @var	string
+	 */
+	protected $_create_table_if	= FALSE;
+
 	/**
 	 * DROP DATABASE statement
 	 *
@@ -60,13 +67,6 @@ class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
 	 */
 	protected $_drop_database	= FALSE;
 
-	/**
-	 * CREATE TABLE IF statement
-	 *
-	 * @var	string
-	 */
-	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';
-
 	/**
 	 * UNSIGNED support
 	 *
@@ -146,4 +146,31 @@ class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
 		// Not supported - sequences and triggers must be used instead
 	}
 
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param	array	&$attributes
+	 * @return	void
+	 */
+	protected function _attr_type(&$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'MEDIUMINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'INT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			case 'BIGINT':
+				$attributes['TYPE'] = 'NUMBER';
+				return;
+			default: return;
+		}
+	}
 }
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
index 33344883..066dd961 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -160,6 +160,19 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * Platform-dependent string escape
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	protected function _escape_str($str)
+	{
+		$this->display_error('db_unsupported_feature');
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Determines if a query is a "write" type.
 	 *
@@ -168,7 +181,7 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 */
 	public function is_write_type($sql)
 	{
-		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#i', $sql))
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
 		{
 			return FALSE;
 		}
@@ -213,72 +226,4 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	{
 		return 'SELECT column_name FROM information_schema.columns WHERE table_name = '.$this->escape($table);
 	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	$table
-	 * @param	array	$values
-	 * @return	string
-	 */
-	protected function _update($table, $values)
-	{
-		$this->qb_limit = FALSE;
-		$this->qb_orderby = array();
-		return parent::_update($table, $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 *
-	 * If the database does not support the TRUNCATE statement,
-	 * then this method maps to 'DELETE FROM table'
-	 *
-	 * @param	string	$table
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'DELETE FROM '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Delete statement
-	 *
-	 * Generates a platform-specific delete string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @return	string
-	 */
-	protected function _delete($table)
-	{
-		$this->qb_limit = FALSE;
-		return parent::_delete($table);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * LIMIT
-	 *
-	 * Generates a platform-specific LIMIT clause
-	 *
-	 * @param	string	$sql	SQL Query
-	 * @return	string
-	 */
-	protected function _limit($sql)
-	{
-		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$this->qb_limit.' ', $sql);
-	}
-
 }
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
index 7c65daa8..a2a3bada 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_odbc_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
index ee8f7634..9aed3a2f 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -154,7 +154,7 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 */
 	public function is_write_type($sql)
 	{
-		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#i', $sql))
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
 		{
 			return FALSE;
 		}
@@ -326,13 +326,13 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 		$ids = array();
 		foreach ($values as $key => $val)
 		{
-			$ids[] = $val[$index];
+			$ids[] = $val[$index]['value'];
 
 			foreach (array_keys($val) as $field)
 			{
 				if ($field !== $index)
 				{
-					$final[$field][] = 'WHEN '.$val[$index].' THEN '.$val[$field];
+					$final[$val[$field]['field']][] = 'WHEN '.$val[$index]['value'].' THEN '.$val[$field]['value'];
 				}
 			}
 		}
@@ -340,12 +340,12 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 		$cases = '';
 		foreach ($final as $k => $v)
 		{
-			$cases .= $k.' = (CASE '.$index."\n"
+			$cases .= $k.' = (CASE '.$val[$index]['field']."\n"
 				.implode("\n", $v)."\n"
 				.'ELSE '.$k.' END), ';
 		}
 
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+		$this->where($val[$index]['field'].' IN('.implode(',', $ids).')', NULL, FALSE);
 
 		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
index 214b6f52..b00af4ad 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -168,7 +168,7 @@ class CI_DB_pdo_pgsql_forge extends CI_DB_pdo_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
-		// Reset field lenghts for data types that don't support it
+		// Reset field lengths for data types that don't support it
 		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
 		{
 			$attributes['CONSTRAINT'] = NULL;
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
index 62690139..9b70f3ea 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -66,7 +66,7 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	 *
 	 * @var	array
 	 */
-	protected $_random_keyword = ' RANDOM()';
+	protected $_random_keyword = array('RANDOM()', 'RANDOM()');
 
 	// --------------------------------------------------------------------
 
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
index f6f9bb48..18c475b1 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -101,7 +101,7 @@ class CI_DB_pdo_sqlite_forge extends CI_DB_pdo_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function create_database($db_name = '')
+	public function create_database($db_name)
 	{
 		// In SQLite, a database is created when you connect to the database.
 		// We'll return TRUE so that an error isn't generated
@@ -116,7 +116,7 @@ class CI_DB_pdo_sqlite_forge extends CI_DB_pdo_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		// In SQLite, a database is dropped when we delete a file
 		if (file_exists($this->db->database))
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index dfccb7d6..07c429ee 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -363,7 +363,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 }
diff --git a/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php b/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
index 602f895f..82a0d515 100644
--- a/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
+++ b/src/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -111,6 +111,11 @@ class CI_DB_pdo_sqlsrv_forge extends CI_DB_pdo_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/src/system/database/drivers/postgre/postgre_driver.php b/src/system/database/drivers/postgre/postgre_driver.php
index 58d44518..bcdfc060 100644
--- a/src/system/database/drivers/postgre/postgre_driver.php
+++ b/src/system/database/drivers/postgre/postgre_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
@@ -130,9 +130,9 @@ class CI_DB_postgre_driver extends CI_DB {
 		 */
 		foreach (array('connect_timeout', 'options', 'sslmode', 'service') as $key)
 		{
-			if (isset($this->$key) && is_string($this->key) && $this->key !== '')
+			if (isset($this->$key) && is_string($this->$key) && $this->$key !== '')
 			{
-				$this->dsn .= $key."='".$this->key."' ";
+				$this->dsn .= $key."='".$this->$key."' ";
 			}
 		}
 
@@ -288,7 +288,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public function is_write_type($sql)
 	{
-		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#i', $sql))
+		if (preg_match('#^(INSERT|UPDATE).*RETURNING\s.+(\,\s?.+)*$#is', $sql))
 		{
 			return FALSE;
 		}
@@ -299,7 +299,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -471,7 +471,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -550,13 +550,13 @@ class CI_DB_postgre_driver extends CI_DB {
 		$ids = array();
 		foreach ($values as $key => $val)
 		{
-			$ids[] = $val[$index];
+			$ids[] = $val[$index]['value'];
 
 			foreach (array_keys($val) as $field)
 			{
 				if ($field !== $index)
 				{
-					$final[$field][] = 'WHEN '.$val[$index].' THEN '.$val[$field];
+					$final[$val[$field]['field']][] = 'WHEN '.$val[$index]['value'].' THEN '.$val[$field]['value'];
 				}
 			}
 		}
@@ -564,12 +564,12 @@ class CI_DB_postgre_driver extends CI_DB {
 		$cases = '';
 		foreach ($final as $k => $v)
 		{
-			$cases .= $k.' = (CASE '.$index."\n"
+			$cases .= $k.' = (CASE '.$val[$index]['field']."\n"
 				.implode("\n", $v)."\n"
 				.'ELSE '.$k.' END), ';
 		}
 
-		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+		$this->where($val[$index]['field'].' IN('.implode(',', $ids).')', NULL, FALSE);
 
 		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
diff --git a/src/system/database/drivers/postgre/postgre_forge.php b/src/system/database/drivers/postgre/postgre_forge.php
index 8d985ba7..cdbff4c4 100644
--- a/src/system/database/drivers/postgre/postgre_forge.php
+++ b/src/system/database/drivers/postgre/postgre_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
@@ -163,7 +163,7 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
-		// Reset field lenghts for data types that don't support it
+		// Reset field lengths for data types that don't support it
 		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
 		{
 			$attributes['CONSTRAINT'] = NULL;
diff --git a/src/system/database/drivers/postgre/postgre_result.php b/src/system/database/drivers/postgre/postgre_result.php
index 354bb08d..57864a7f 100644
--- a/src/system/database/drivers/postgre/postgre_result.php
+++ b/src/system/database/drivers/postgre/postgre_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/postgre/postgre_utility.php b/src/system/database/drivers/postgre/postgre_utility.php
index bb5e6e04..5ca358da 100644
--- a/src/system/database/drivers/postgre/postgre_utility.php
+++ b/src/system/database/drivers/postgre/postgre_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/sqlite/sqlite_driver.php b/src/system/database/drivers/sqlite/sqlite_driver.php
index 16b8c29c..03c96e44 100644
--- a/src/system/database/drivers/sqlite/sqlite_driver.php
+++ b/src/system/database/drivers/sqlite/sqlite_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/sqlite/sqlite_forge.php b/src/system/database/drivers/sqlite/sqlite_forge.php
index 8a165943..a0fc0cdb 100644
--- a/src/system/database/drivers/sqlite/sqlite_forge.php
+++ b/src/system/database/drivers/sqlite/sqlite_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
@@ -75,7 +75,7 @@ class CI_DB_sqlite_forge extends CI_DB_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function create_database($db_name = '')
+	public function create_database($db_name)
 	{
 		// In SQLite, a database is created when you connect to the database.
 		// We'll return TRUE so that an error isn't generated
@@ -90,7 +90,7 @@ class CI_DB_sqlite_forge extends CI_DB_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		if ( ! file_exists($this->db->database) OR ! @unlink($this->db->database))
 		{
diff --git a/src/system/database/drivers/sqlite/sqlite_result.php b/src/system/database/drivers/sqlite/sqlite_result.php
index d40b98aa..34d3ac3c 100644
--- a/src/system/database/drivers/sqlite/sqlite_result.php
+++ b/src/system/database/drivers/sqlite/sqlite_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/sqlite/sqlite_utility.php b/src/system/database/drivers/sqlite/sqlite_utility.php
index 59c46f9e..90ca4b16 100644
--- a/src/system/database/drivers/sqlite/sqlite_utility.php
+++ b/src/system/database/drivers/sqlite/sqlite_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.0
diff --git a/src/system/database/drivers/sqlite3/sqlite3_driver.php b/src/system/database/drivers/sqlite3/sqlite3_driver.php
index 9743499b..d131baad 100644
--- a/src/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/src/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -168,7 +168,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -291,7 +291,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/src/system/database/drivers/sqlite3/sqlite3_forge.php b/src/system/database/drivers/sqlite3/sqlite3_forge.php
index 43cbe33e..5ee6daae 100644
--- a/src/system/database/drivers/sqlite3/sqlite3_forge.php
+++ b/src/system/database/drivers/sqlite3/sqlite3_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -87,7 +87,7 @@ class CI_DB_sqlite3_forge extends CI_DB_forge {
 	 * @param	string	$db_name
 	 * @return	bool
 	 */
-	public function create_database($db_name = '')
+	public function create_database($db_name)
 	{
 		// In SQLite, a database is created when you connect to the database.
 		// We'll return TRUE so that an error isn't generated
@@ -102,7 +102,7 @@ class CI_DB_sqlite3_forge extends CI_DB_forge {
 	 * @param	string	$db_name	(ignored)
 	 * @return	bool
 	 */
-	public function drop_database($db_name = '')
+	public function drop_database($db_name)
 	{
 		// In SQLite, a database is dropped when we delete a file
 		if (file_exists($this->db->database))
diff --git a/src/system/database/drivers/sqlite3/sqlite3_result.php b/src/system/database/drivers/sqlite3/sqlite3_result.php
index aa559eef..03751f0d 100644
--- a/src/system/database/drivers/sqlite3/sqlite3_result.php
+++ b/src/system/database/drivers/sqlite3/sqlite3_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/sqlite3/sqlite3_utility.php b/src/system/database/drivers/sqlite3/sqlite3_utility.php
index b47c086f..20d562f9 100644
--- a/src/system/database/drivers/sqlite3/sqlite3_utility.php
+++ b/src/system/database/drivers/sqlite3/sqlite3_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/database/drivers/sqlsrv/sqlsrv_driver.php b/src/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 0cd9ce16..a43e2539 100644
--- a/src/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/src/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.3
@@ -171,6 +171,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 		if ($this->_execute('USE '.$this->escape_identifiers($database)))
 		{
 			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
@@ -357,7 +358,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -524,7 +525,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/src/system/database/drivers/sqlsrv/sqlsrv_forge.php b/src/system/database/drivers/sqlsrv/sqlsrv_forge.php
index f915dad3..aa8490ee 100644
--- a/src/system/database/drivers/sqlsrv/sqlsrv_forge.php
+++ b/src/system/database/drivers/sqlsrv/sqlsrv_forge.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.3
@@ -111,6 +111,11 @@ class CI_DB_sqlsrv_forge extends CI_DB_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
+		if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== FALSE)
+		{
+			unset($attributes['CONSTRAINT']);
+		}
+
 		switch (strtoupper($attributes['TYPE']))
 		{
 			case 'MEDIUMINT':
diff --git a/src/system/database/drivers/sqlsrv/sqlsrv_result.php b/src/system/database/drivers/sqlsrv/sqlsrv_result.php
index fde7264b..f784ebea 100644
--- a/src/system/database/drivers/sqlsrv/sqlsrv_result.php
+++ b/src/system/database/drivers/sqlsrv/sqlsrv_result.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.3
diff --git a/src/system/database/drivers/sqlsrv/sqlsrv_utility.php b/src/system/database/drivers/sqlsrv/sqlsrv_utility.php
index 726fe3ea..19c93d0c 100644
--- a/src/system/database/drivers/sqlsrv/sqlsrv_utility.php
+++ b/src/system/database/drivers/sqlsrv/sqlsrv_utility.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.3
diff --git a/src/system/helpers/array_helper.php b/src/system/helpers/array_helper.php
index 3fdccf90..74c7c15a 100644
--- a/src/system/helpers/array_helper.php
+++ b/src/system/helpers/array_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/captcha_helper.php b/src/system/helpers/captcha_helper.php
index 3c1e006f..8f44806c 100644
--- a/src/system/helpers/captcha_helper.php
+++ b/src/system/helpers/captcha_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -110,7 +110,8 @@ if ( ! function_exists('create_captcha'))
 		$current_dir = @opendir($img_path);
 		while ($filename = @readdir($current_dir))
 		{
-			if (substr($filename, -4) === '.jpg' && (str_replace('.jpg', '', $filename) + $expiration) < $now)
+			if (in_array(substr($filename, -4), array('.jpg', '.png'))
+				&& (str_replace(array('.jpg', '.png'), '', $filename) + $expiration) < $now)
 			{
 				@unlink($img_path.$filename);
 			}
diff --git a/src/system/helpers/cookie_helper.php b/src/system/helpers/cookie_helper.php
index ca432449..b943edba 100644
--- a/src/system/helpers/cookie_helper.php
+++ b/src/system/helpers/cookie_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -67,7 +67,7 @@ if ( ! function_exists('set_cookie'))
 	 * @param	bool	true makes the cookie accessible via http(s) only (no javascript)
 	 * @return	void
 	 */
-	function set_cookie($name, $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = FALSE, $httponly = FALSE)
+	function set_cookie($name, $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = NULL, $httponly = NULL)
 	{
 		// Set the config file options
 		get_instance()->input->set_cookie($name, $value, $expire, $domain, $path, $prefix, $secure, $httponly);
diff --git a/src/system/helpers/date_helper.php b/src/system/helpers/date_helper.php
index c43209f0..bb150426 100644
--- a/src/system/helpers/date_helper.php
+++ b/src/system/helpers/date_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -496,6 +496,7 @@ if ( ! function_exists('nice_date'))
 	 * Turns many "reasonably-date-like" strings into something
 	 * that is actually useful. This only works for dates after unix epoch.
 	 *
+	 * @deprecated	3.1.3	Use DateTime::createFromFormat($input_format, $input)->format($output_format);
 	 * @param	string	The terribly formatted date-like string
 	 * @param	string	Date format to return (same as php date function)
 	 * @return	string
@@ -529,9 +530,9 @@ if ( ! function_exists('nice_date'))
 		}
 
 		// Date Like: YYYYMMDD
-		if (preg_match('/^(\d{2})\d{2}(\d{4})$/i', $bad_date, $matches))
+		if (preg_match('/^\d{8}$/i', $bad_date, $matches))
 		{
-			return date($format, strtotime($matches[1].'/01/'.$matches[2]));
+			return DateTime::createFromFormat('Ymd', $bad_date)->format($format);
 		}
 
 		// Date Like: MM-DD-YYYY __or__ M-D-YYYY (or anything in between)
@@ -707,87 +708,32 @@ if ( ! function_exists('date_range'))
 
 		$range = array();
 
-		/* NOTE: Even though the DateTime object has many useful features, it appears that
-		 *	 it doesn't always handle properly timezones, when timestamps are passed
-		 *	 directly to its constructor. Neither of the following gave proper results:
-		 *
-		 *		new DateTime('<timestamp>')
-		 *		new DateTime('<timestamp>', '<timezone>')
-		 *
-		 *	 --- available in PHP 5.3:
-		 *
-		 *		DateTime::createFromFormat('<format>', '<timestamp>')
-		 *		DateTime::createFromFormat('<format>', '<timestamp>', '<timezone')
-		 *
-		 *	 ... so we'll have to set the timestamp after the object is instantiated.
-		 *	 Furthermore, in PHP 5.3 we can use DateTime::setTimestamp() to do that and
-		 *	 given that we have UNIX timestamps - we should use it.
-		*/
 		$from = new DateTime();
+		$from->setTimestamp($unix_start);
 
-		if (is_php('5.3'))
-		{
-			$from->setTimestamp($unix_start);
-			if ($is_unix)
-			{
-				$arg = new DateTime();
-				$arg->setTimestamp($mixed);
-			}
-			else
-			{
-				$arg = (int) $mixed;
-			}
-
-			$period = new DatePeriod($from, new DateInterval('P1D'), $arg);
-			foreach ($period as $date)
-			{
-				$range[] = $date->format($format);
-			}
-
-			/* If a period end date was passed to the DatePeriod constructor, it might not
-			 * be in our results. Not sure if this is a bug or it's just possible because
-			 * the end date might actually be less than 24 hours away from the previously
-			 * generated DateTime object, but either way - we have to append it manually.
-			 */
-			if ( ! is_int($arg) && $range[count($range) - 1] !== $arg->format($format))
-			{
-				$range[] = $arg->format($format);
-			}
-
-			return $range;
-		}
-
-		$from->setDate(date('Y', $unix_start), date('n', $unix_start), date('j', $unix_start));
-		$from->setTime(date('G', $unix_start), date('i', $unix_start), date('s', $unix_start));
 		if ($is_unix)
 		{
 			$arg = new DateTime();
-			$arg->setDate(date('Y', $mixed), date('n', $mixed), date('j', $mixed));
-			$arg->setTime(date('G', $mixed), date('i', $mixed), date('s', $mixed));
+			$arg->setTimestamp($mixed);
 		}
 		else
 		{
 			$arg = (int) $mixed;
 		}
-		$range[] = $from->format($format);
 
-		if (is_int($arg)) // Day intervals
+		$period = new DatePeriod($from, new DateInterval('P1D'), $arg);
+		foreach ($period as $date)
 		{
-			do
-			{
-				$from->modify('+1 day');
-				$range[] = $from->format($format);
-			}
-			while (--$arg > 0);
+			$range[] = $date->format($format);
 		}
-		else // end date UNIX timestamp
-		{
-			for ($from->modify('+1 day'), $end_check = $arg->format('Ymd'); $from->format('Ymd') < $end_check; $from->modify('+1 day'))
-			{
-				$range[] = $from->format($format);
-			}
 
-			// Our loop only appended dates prior to our end date
+		/* If a period end date was passed to the DatePeriod constructor, it might not
+		 * be in our results. Not sure if this is a bug or it's just possible because
+		 * the end date might actually be less than 24 hours away from the previously
+		 * generated DateTime object, but either way - we have to append it manually.
+		 */
+		if ( ! is_int($arg) && $range[count($range) - 1] !== $arg->format($format))
+		{
 			$range[] = $arg->format($format);
 		}
 
diff --git a/src/system/helpers/directory_helper.php b/src/system/helpers/directory_helper.php
index cdc4c16b..2785241e 100644
--- a/src/system/helpers/directory_helper.php
+++ b/src/system/helpers/directory_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/download_helper.php b/src/system/helpers/download_helper.php
index a6463dfd..b2a1458d 100644
--- a/src/system/helpers/download_helper.php
+++ b/src/system/helpers/download_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/email_helper.php b/src/system/helpers/email_helper.php
index 35944fc7..b3755d45 100644
--- a/src/system/helpers/email_helper.php
+++ b/src/system/helpers/email_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/file_helper.php b/src/system/helpers/file_helper.php
index 0d8d1d0d..d227f468 100644
--- a/src/system/helpers/file_helper.php
+++ b/src/system/helpers/file_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -138,13 +138,15 @@ if ( ! function_exists('delete_files'))
 		{
 			if ($filename !== '.' && $filename !== '..')
 			{
-				if (is_dir($path.DIRECTORY_SEPARATOR.$filename) && $filename[0] !== '.')
+				$filepath = $path.DIRECTORY_SEPARATOR.$filename;
+
+				if (is_dir($filepath) && $filename[0] !== '.' && ! is_link($filepath))
 				{
-					delete_files($path.DIRECTORY_SEPARATOR.$filename, $del_dir, $htdocs, $_level + 1);
+					delete_files($filepath, $del_dir, $htdocs, $_level + 1);
 				}
 				elseif ($htdocs !== TRUE OR ! preg_match('/^(\.htaccess|index\.(html|htm|php)|web\.config)$/i', $filename))
 				{
-					@unlink($path.DIRECTORY_SEPARATOR.$filename);
+					@unlink($filepath);
 				}
 			}
 		}
diff --git a/src/system/helpers/form_helper.php b/src/system/helpers/form_helper.php
index 3e103952..a49eea80 100644
--- a/src/system/helpers/form_helper.php
+++ b/src/system/helpers/form_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -90,20 +90,49 @@ if ( ! function_exists('form_open'))
 
 		$form = '<form action="'.$action.'"'.$attributes.">\n";
 
-		// Add CSRF field if enabled, but leave it out for GET requests and requests to external websites
-		if ($CI->config->item('csrf_protection') === TRUE && strpos($action, $CI->config->base_url()) !== FALSE && ! stripos($form, 'method="get"'))
-		{
-			$hidden[$CI->security->get_csrf_token_name()] = $CI->security->get_csrf_hash();
-		}
-
 		if (is_array($hidden))
 		{
 			foreach ($hidden as $name => $value)
 			{
-				$form .= '<input type="hidden" name="'.$name.'" value="'.html_escape($value).'" style="display:none;" />'."\n";
+				$form .= '<input type="hidden" name="'.$name.'" value="'.html_escape($value).'" />'."\n";
 			}
 		}
 
+		// Add CSRF field if enabled, but leave it out for GET requests and requests to external websites
+		if ($CI->config->item('csrf_protection') === TRUE && strpos($action, $CI->config->base_url()) !== FALSE && ! stripos($form, 'method="get"'))
+		{
+			// Prepend/append random-length "white noise" around the CSRF
+			// token input, as a form of protection against BREACH attacks
+			if (FALSE !== ($noise = $CI->security->get_random_bytes(1)))
+			{
+				list(, $noise) = unpack('c', $noise);
+			}
+			else
+			{
+				$noise = mt_rand(-128, 127);
+			}
+
+			// Prepend if $noise has a negative value, append if positive, do nothing for zero
+			$prepend = $append = '';
+			if ($noise < 0)
+			{
+				$prepend = str_repeat(" ", abs($noise));
+			}
+			elseif ($noise > 0)
+			{
+				$append  = str_repeat(" ", $noise);
+			}
+
+			$form .= sprintf(
+				'%s<input type="hidden" name="%s" value="%s" />%s%s',
+				$prepend,
+				$CI->security->get_csrf_token_name(),
+				$CI->security->get_csrf_hash(),
+				$append,
+				"\n"
+			);
+		}
+
 		return $form;
 	}
 }
@@ -568,7 +597,7 @@ if ( ! function_exists('form_label'))
 	 *
 	 * @param	string	The text to appear onscreen
 	 * @param	string	The id the label applies to
-	 * @param	string	Additional attributes
+	 * @param	array	Additional attributes
 	 * @return	string
 	 */
 	function form_label($label_text = '', $id = '', $attributes = array())
diff --git a/src/system/helpers/html_helper.php b/src/system/helpers/html_helper.php
index fdc463fc..87a5f9b2 100644
--- a/src/system/helpers/html_helper.php
+++ b/src/system/helpers/html_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -192,7 +192,7 @@ if ( ! function_exists('img'))
 
 		foreach ($src as $k => $v)
 		{
-			if ($k === 'src' && ! preg_match('#^([a-z]+:)?//#i', $v))
+			if ($k === 'src' && ! preg_match('#^(data:[a-z,;])|(([a-z]+:)?(?<!data:)//)#i', $v))
 			{
 				if ($index_page === TRUE)
 				{
diff --git a/src/system/helpers/inflector_helper.php b/src/system/helpers/inflector_helper.php
index c064d8de..26a5a5ca 100644
--- a/src/system/helpers/inflector_helper.php
+++ b/src/system/helpers/inflector_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -238,8 +238,37 @@ if ( ! function_exists('is_countable'))
 		return ! in_array(
 			strtolower($word),
 			array(
-				'equipment', 'information', 'rice', 'money',
-				'species', 'series', 'fish', 'meta'
+				'audio',
+				'bison',
+				'chassis',
+				'compensation',
+				'coreopsis',
+				'data',
+				'deer',
+				'education',
+				'emoji',
+				'equipment',
+				'fish',
+				'furniture',
+				'gold',
+				'information',
+				'knowledge',
+				'love',
+				'rain',
+				'money',
+				'moose',
+				'nutrition',
+				'offspring',
+				'plankton',
+				'pokemon',
+				'police',
+				'rice',
+				'series',
+				'sheep',
+				'species',
+				'swine',
+				'traffic',
+				'wheat'
 			)
 		);
 	}
diff --git a/src/system/helpers/language_helper.php b/src/system/helpers/language_helper.php
index 3721164b..d26cf5b8 100644
--- a/src/system/helpers/language_helper.php
+++ b/src/system/helpers/language_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/number_helper.php b/src/system/helpers/number_helper.php
index e7810c70..cc8a7760 100644
--- a/src/system/helpers/number_helper.php
+++ b/src/system/helpers/number_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/path_helper.php b/src/system/helpers/path_helper.php
index 838ece9e..6896cb97 100644
--- a/src/system/helpers/path_helper.php
+++ b/src/system/helpers/path_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -61,7 +61,7 @@ if ( ! function_exists('set_realpath'))
 	function set_realpath($path, $check_existance = FALSE)
 	{
 		// Security check to make sure the path is NOT a URL. No remote file inclusion!
-		if (preg_match('#^(http:\/\/|https:\/\/|www\.|ftp)#i', $path) OR filter_var($path, FILTER_VALIDATE_IP) === $path )
+		if (preg_match('#^(http:\/\/|https:\/\/|www\.|ftp|php:\/\/)#i', $path) OR filter_var($path, FILTER_VALIDATE_IP) === $path)
 		{
 			show_error('The path you submitted must be a local server path, not a URL');
 		}
diff --git a/src/system/helpers/security_helper.php b/src/system/helpers/security_helper.php
index 4eb63883..5e2970a5 100644
--- a/src/system/helpers/security_helper.php
+++ b/src/system/helpers/security_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/smiley_helper.php b/src/system/helpers/smiley_helper.php
index 688ca24c..2c9a3b4a 100644
--- a/src/system/helpers/smiley_helper.php
+++ b/src/system/helpers/smiley_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/string_helper.php b/src/system/helpers/string_helper.php
index db531fa9..93446b82 100644
--- a/src/system/helpers/string_helper.php
+++ b/src/system/helpers/string_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -195,9 +195,7 @@ if ( ! function_exists('reduce_multiples'))
 if ( ! function_exists('random_string'))
 {
 	/**
-	 * Create a Random String
-	 *
-	 * Useful for generating passwords or hashes.
+	 * Create a "Random" String
 	 *
 	 * @param	string	type of random string.  basic, alpha, alnum, numeric, nozero, unique, md5, encrypt and sha1
 	 * @param	int	number of characters
diff --git a/src/system/helpers/text_helper.php b/src/system/helpers/text_helper.php
index 4f9210f2..217729b7 100644
--- a/src/system/helpers/text_helper.php
+++ b/src/system/helpers/text_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -102,7 +102,7 @@ if ( ! function_exists('character_limiter'))
 		}
 
 		// a bit complicated, but faster than preg_replace with \s+
-		$str = preg_replace('/ {2,}/', ' ', str_replace(array("\r", "\n", "\t", "\x0B", "\x0C"), ' ', $str));
+		$str = preg_replace('/ {2,}/', ' ', str_replace(array("\r", "\n", "\t", "\v", "\f"), ' ', $str));
 
 		if (mb_strlen($str) <= $n)
 		{
@@ -138,7 +138,10 @@ if ( ! function_exists('ascii_to_entities'))
 	function ascii_to_entities($str)
 	{
 		$out = '';
-		for ($i = 0, $s = strlen($str) - 1, $count = 1, $temp = array(); $i <= $s; $i++)
+		$length = defined('MB_OVERLOAD_STRING')
+			? mb_strlen($str, '8bit') - 1
+			: strlen($str) - 1;
+		for ($i = 0, $count = 1, $temp = array(); $i <= $length; $i++)
 		{
 			$ordinal = ord($str[$i]);
 
@@ -176,7 +179,7 @@ if ( ! function_exists('ascii_to_entities'))
 					$temp = array();
 				}
 				// If this is the last iteration, just output whatever we have
-				elseif ($i === $s)
+				elseif ($i === $length)
 				{
 					$out .= '&#'.implode(';', $temp).';';
 				}
diff --git a/src/system/helpers/typography_helper.php b/src/system/helpers/typography_helper.php
index 928cb6d0..183e117b 100644
--- a/src/system/helpers/typography_helper.php
+++ b/src/system/helpers/typography_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/url_helper.php b/src/system/helpers/url_helper.php
index fd7b5e11..84023aff 100644
--- a/src/system/helpers/url_helper.php
+++ b/src/system/helpers/url_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/helpers/xml_helper.php b/src/system/helpers/xml_helper.php
index 3489da91..a12ee25d 100644
--- a/src/system/helpers/xml_helper.php
+++ b/src/system/helpers/xml_helper.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/calendar_lang.php b/src/system/language/english/calendar_lang.php
index 8af5e805..77911e98 100644
--- a/src/system/language/english/calendar_lang.php
+++ b/src/system/language/english/calendar_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/date_lang.php b/src/system/language/english/date_lang.php
index 39af5a23..bb454edf 100644
--- a/src/system/language/english/date_lang.php
+++ b/src/system/language/english/date_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/db_lang.php b/src/system/language/english/db_lang.php
index ed93452b..b44bda95 100644
--- a/src/system/language/english/db_lang.php
+++ b/src/system/language/english/db_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/email_lang.php b/src/system/language/english/email_lang.php
index 84fb0910..22dc0fa7 100644
--- a/src/system/language/english/email_lang.php
+++ b/src/system/language/english/email_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/form_validation_lang.php b/src/system/language/english/form_validation_lang.php
index 92d6d5eb..aa9ff330 100644
--- a/src/system/language/english/form_validation_lang.php
+++ b/src/system/language/english/form_validation_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/ftp_lang.php b/src/system/language/english/ftp_lang.php
index 9e72bce4..eada3e5d 100644
--- a/src/system/language/english/ftp_lang.php
+++ b/src/system/language/english/ftp_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/imglib_lang.php b/src/system/language/english/imglib_lang.php
index 7f23233b..218874cf 100644
--- a/src/system/language/english/imglib_lang.php
+++ b/src/system/language/english/imglib_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -51,6 +51,7 @@ $lang['imglib_libpath_invalid'] = 'The path to your image library is not correct
 $lang['imglib_image_process_failed'] = 'Image processing failed. Please verify that your server supports the chosen protocol and that the path to your image library is correct.';
 $lang['imglib_rotation_angle_required'] = 'An angle of rotation is required to rotate the image.';
 $lang['imglib_invalid_path'] = 'The path to the image is not correct.';
+$lang['imglib_invalid_image'] = 'The provided image is not valid.';
 $lang['imglib_copy_failed'] = 'The image copy routine failed.';
 $lang['imglib_missing_font'] = 'Unable to find a font to use.';
 $lang['imglib_save_failed'] = 'Unable to save the image. Please make sure the image and file directory are writable.';
diff --git a/src/system/language/english/migration_lang.php b/src/system/language/english/migration_lang.php
index bce9210d..16849609 100644
--- a/src/system/language/english/migration_lang.php
+++ b/src/system/language/english/migration_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/language/english/number_lang.php b/src/system/language/english/number_lang.php
index 0aaf51e7..9723ce5e 100644
--- a/src/system/language/english/number_lang.php
+++ b/src/system/language/english/number_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/pagination_lang.php b/src/system/language/english/pagination_lang.php
index 4d36bdee..d24dd047 100644
--- a/src/system/language/english/pagination_lang.php
+++ b/src/system/language/english/pagination_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/profiler_lang.php b/src/system/language/english/profiler_lang.php
index 2d8fa51f..20949a20 100644
--- a/src/system/language/english/profiler_lang.php
+++ b/src/system/language/english/profiler_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/unit_test_lang.php b/src/system/language/english/unit_test_lang.php
index 29a4137a..a89cb2d9 100644
--- a/src/system/language/english/unit_test_lang.php
+++ b/src/system/language/english/unit_test_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/language/english/upload_lang.php b/src/system/language/english/upload_lang.php
index 058dca99..ec611f9a 100644
--- a/src/system/language/english/upload_lang.php
+++ b/src/system/language/english/upload_lang.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/libraries/Cache/Cache.php b/src/system/libraries/Cache/Cache.php
index 349af157..267dffb0 100644
--- a/src/system/libraries/Cache/Cache.php
+++ b/src/system/libraries/Cache/Cache.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.0
diff --git a/src/system/libraries/Cache/drivers/Cache_apc.php b/src/system/libraries/Cache/drivers/Cache_apc.php
index 07ea8f47..f2b61adb 100644
--- a/src/system/libraries/Cache/drivers/Cache_apc.php
+++ b/src/system/libraries/Cache/drivers/Cache_apc.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.0
@@ -97,7 +97,7 @@ class CI_Cache_apc extends CI_Driver {
 	 *
 	 * @param	string	$id	Cache ID
 	 * @param	mixed	$data	Data to store
-	 * @param	int	$ttol	Length of time (in seconds) to cache the data
+	 * @param	int	$ttl	Length of time (in seconds) to cache the data
 	 * @param	bool	$raw	Whether to store the raw value
 	 * @return	bool	TRUE on success, FALSE on failure
 	 */
diff --git a/src/system/libraries/Cache/drivers/Cache_dummy.php b/src/system/libraries/Cache/drivers/Cache_dummy.php
index 4323a68a..c6d9a61f 100644
--- a/src/system/libraries/Cache/drivers/Cache_dummy.php
+++ b/src/system/libraries/Cache/drivers/Cache_dummy.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0
diff --git a/src/system/libraries/Cache/drivers/Cache_file.php b/src/system/libraries/Cache/drivers/Cache_file.php
index e1ce16a5..8a36e9d7 100644
--- a/src/system/libraries/Cache/drivers/Cache_file.php
+++ b/src/system/libraries/Cache/drivers/Cache_file.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0
@@ -120,7 +120,7 @@ class CI_Cache_file extends CI_Driver {
 	 */
 	public function delete($id)
 	{
-		return file_exists($this->_cache_path.$id) ? unlink($this->_cache_path.$id) : FALSE;
+		return is_file($this->_cache_path.$id) ? unlink($this->_cache_path.$id) : FALSE;
 	}
 
 	// ------------------------------------------------------------------------
@@ -216,7 +216,7 @@ class CI_Cache_file extends CI_Driver {
 	 */
 	public function get_metadata($id)
 	{
-		if ( ! file_exists($this->_cache_path.$id))
+		if ( ! is_file($this->_cache_path.$id))
 		{
 			return FALSE;
 		}
@@ -227,13 +227,13 @@ class CI_Cache_file extends CI_Driver {
 		{
 			$mtime = filemtime($this->_cache_path.$id);
 
-			if ( ! isset($data['ttl']))
+			if ( ! isset($data['ttl'], $data['time']))
 			{
 				return FALSE;
 			}
 
 			return array(
-				'expire' => $mtime + $data['ttl'],
+				'expire' => $data['time'] + $data['ttl'],
 				'mtime'	 => $mtime
 			);
 		}
diff --git a/src/system/libraries/Cache/drivers/Cache_memcached.php b/src/system/libraries/Cache/drivers/Cache_memcached.php
index 6dee1e8e..b642a2c0 100644
--- a/src/system/libraries/Cache/drivers/Cache_memcached.php
+++ b/src/system/libraries/Cache/drivers/Cache_memcached.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0
@@ -110,7 +110,7 @@ class CI_Cache_memcached extends CI_Driver {
 
 			if ($this->_memcached instanceof Memcache)
 			{
-				// Third parameter is persistance and defaults to TRUE.
+				// Third parameter is persistence and defaults to TRUE.
 				$this->_memcached->addServer(
 					$cache_server['hostname'],
 					$cache_server['port'],
@@ -295,7 +295,7 @@ class CI_Cache_memcached extends CI_Driver {
 		{
 			$this->_memcached->close();
 		}
-		elseif ($this->_memcached instanceof Memcached)
+		elseif ($this->_memcached instanceof Memcached && method_exists($this->_memcached, 'quit'))
 		{
 			$this->_memcached->quit();
 		}
diff --git a/src/system/libraries/Cache/drivers/Cache_redis.php b/src/system/libraries/Cache/drivers/Cache_redis.php
index d4d95ebb..ac67be07 100644
--- a/src/system/libraries/Cache/drivers/Cache_redis.php
+++ b/src/system/libraries/Cache/drivers/Cache_redis.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/libraries/Cache/drivers/Cache_wincache.php b/src/system/libraries/Cache/drivers/Cache_wincache.php
index d6a0d4fb..f296a5e2 100644
--- a/src/system/libraries/Cache/drivers/Cache_wincache.php
+++ b/src/system/libraries/Cache/drivers/Cache_wincache.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/libraries/Calendar.php b/src/system/libraries/Calendar.php
index 1f8ef814..edb0fb4d 100644
--- a/src/system/libraries/Calendar.php
+++ b/src/system/libraries/Calendar.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/libraries/Cart.php b/src/system/libraries/Cart.php
index 44d87e0b..734c4342 100644
--- a/src/system/libraries/Cart.php
+++ b/src/system/libraries/Cart.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/libraries/Driver.php b/src/system/libraries/Driver.php
index 38c6aefe..00e8416f 100644
--- a/src/system/libraries/Driver.php
+++ b/src/system/libraries/Driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/libraries/Email.php b/src/system/libraries/Email.php
index ed6f737a..955787d2 100644
--- a/src/system/libraries/Email.php
+++ b/src/system/libraries/Email.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -147,14 +147,7 @@ class CI_Email {
 	 *
 	 * @var	string
 	 */
-	public $charset		= 'utf-8';
-
-	/**
-	 * Multipart message
-	 *
-	 * @var	string	'mixed' (in the body) or 'related' (separate)
-	 */
-	public $multipart	= 'mixed';		// "mixed" (in the body) or "related" (separate)
+	public $charset		= 'UTF-8';
 
 	/**
 	 * Alternative message (for HTML messages only)
@@ -260,20 +253,6 @@ class CI_Email {
 	 */
 	protected $_finalbody		= '';
 
-	/**
-	 * multipart/alternative boundary
-	 *
-	 * @var	string
-	 */
-	protected $_alt_boundary	= '';
-
-	/**
-	 * Attachment boundary
-	 *
-	 * @var	string
-	 */
-	protected $_atc_boundary	= '';
-
 	/**
 	 * Final headers to send
 	 *
@@ -395,6 +374,13 @@ class CI_Email {
 		5 => '5 (Lowest)'
 	);
 
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_overload;
+
 	// --------------------------------------------------------------------
 
 	/**
@@ -408,47 +394,26 @@ class CI_Email {
 	public function __construct(array $config = array())
 	{
 		$this->charset = config_item('charset');
-
-		if (count($config) > 0)
-		{
-			$this->initialize($config);
-		}
-		else
-		{
-			$this->_smtp_auth = ! ($this->smtp_user === '' && $this->smtp_pass === '');
-		}
-
+		$this->initialize($config);
 		$this->_safe_mode = ( ! is_php('5.4') && ini_get('safe_mode'));
-		$this->charset = strtoupper($this->charset);
+
+		isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
 
 		log_message('info', 'Email Class Initialized');
 	}
 
 	// --------------------------------------------------------------------
 
-	/**
-	 * Destructor - Releases Resources
-	 *
-	 * @return	void
-	 */
-	public function __destruct()
-	{
-		if (is_resource($this->_smtp_connect))
-		{
-			$this->_send_command('quit');
-		}
-	}
-
-	// --------------------------------------------------------------------
-
 	/**
 	 * Initialize preferences
 	 *
-	 * @param	array
+	 * @param	array	$config
 	 * @return	CI_Email
 	 */
-	public function initialize($config = array())
+	public function initialize(array $config = array())
 	{
+		$this->clear();
+
 		foreach ($config as $key => $val)
 		{
 			if (isset($this->$key))
@@ -465,9 +430,9 @@ class CI_Email {
 				}
 			}
 		}
-		$this->clear();
 
-		$this->_smtp_auth = ! ($this->smtp_user === '' && $this->smtp_pass === '');
+		$this->charset = strtoupper($this->charset);
+		$this->_smtp_auth = isset($this->smtp_user[0], $this->smtp_pass[0]);
 
 		return $this;
 	}
@@ -493,7 +458,6 @@ class CI_Email {
 		$this->_headers		= array();
 		$this->_debug_msg	= array();
 
-		$this->set_header('User-Agent', $this->useragent);
 		$this->set_header('Date', $this->_set_date());
 
 		if ($clear_attachments !== FALSE)
@@ -766,7 +730,8 @@ class CI_Email {
 			'name'		=> array($file, $newname),
 			'disposition'	=> empty($disposition) ? 'attachment' : $disposition,  // Can also be 'inline'  Not sure if it matters
 			'type'		=> $mime,
-			'content'	=> chunk_split(base64_encode($file_content))
+			'content'	=> chunk_split(base64_encode($file_content)),
+			'multipart'	=> 'mixed'
 		);
 
 		return $this;
@@ -784,15 +749,11 @@ class CI_Email {
 	 */
 	public function attachment_cid($filename)
 	{
-		if ($this->multipart !== 'related')
-		{
-			$this->multipart = 'related'; // Thunderbird need this for inline images
-		}
-
 		for ($i = 0, $c = count($this->_attachments); $i < $c; $i++)
 		{
 			if ($this->_attachments[$i]['name'][0] === $filename)
 			{
+				$this->_attachments[$i]['multipart'] = 'related';
 				$this->_attachments[$i]['cid'] = uniqid(basename($this->_attachments[$i]['name'][0]).'@');
 				return $this->_attachments[$i]['cid'];
 			}
@@ -936,19 +897,6 @@ class CI_Email {
 
 	// --------------------------------------------------------------------
 
-	/**
-	 * Set Message Boundary
-	 *
-	 * @return	void
-	 */
-	protected function _set_boundaries()
-	{
-		$this->_alt_boundary = 'B_ALT_'.uniqid(''); // multipart/alternative
-		$this->_atc_boundary = 'B_ATC_'.uniqid(''); // attachment boundary
-	}
-
-	// --------------------------------------------------------------------
-
 	/**
 	 * Get the Message ID
 	 *
@@ -1016,9 +964,9 @@ class CI_Email {
 	{
 		if ($this->mailtype === 'html')
 		{
-			return (count($this->_attachments) === 0) ? 'html' : 'html-attach';
+			return empty($this->_attachments) ? 'html' : 'html-attach';
 		}
-		elseif	($this->mailtype === 'text' && count($this->_attachments) > 0)
+		elseif	($this->mailtype === 'text' && ! empty($this->_attachments))
 		{
 			return 'plain-attach';
 		}
@@ -1097,7 +1045,7 @@ class CI_Email {
 	{
 		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
 		{
-			$email = substr($email, 0, ++$atpos).idn_to_ascii(substr($email, $atpos));
+			$email = self::substr($email, 0, ++$atpos).idn_to_ascii(self::substr($email, $atpos));
 		}
 
 		return (bool) filter_var($email, FILTER_VALIDATE_EMAIL);
@@ -1214,7 +1162,7 @@ class CI_Email {
 		{
 			// Is the line within the allowed character count?
 			// If so we'll join it to the output and continue
-			if (mb_strlen($line) <= $charlim)
+			if (self::strlen($line) <= $charlim)
 			{
 				$output .= $line.$this->newline;
 				continue;
@@ -1230,10 +1178,10 @@ class CI_Email {
 				}
 
 				// Trim the word down
-				$temp .= mb_substr($line, 0, $charlim - 1);
-				$line = mb_substr($line, $charlim - 1);
+				$temp .= self::substr($line, 0, $charlim - 1);
+				$line = self::substr($line, $charlim - 1);
 			}
-			while (mb_strlen($line) > $charlim);
+			while (self::strlen($line) > $charlim);
 
 			// If $temp contains data it means we had to split up an over-length
 			// word into smaller chunks so we'll add it back to our current line
@@ -1262,10 +1210,11 @@ class CI_Email {
 	/**
 	 * Build final headers
 	 *
-	 * @return	string
+	 * @return	void
 	 */
 	protected function _build_headers()
 	{
+		$this->set_header('User-Agent', $this->useragent);
 		$this->set_header('X-Sender', $this->clean_email($this->_headers['From']));
 		$this->set_header('X-Mailer', $this->useragent);
 		$this->set_header('X-Priority', $this->_priorities[$this->priority]);
@@ -1324,7 +1273,6 @@ class CI_Email {
 			$this->_body = $this->word_wrap($this->_body);
 		}
 
-		$this->_set_boundaries();
 		$this->_write_headers();
 
 		$hdr = ($this->_get_protocol() === 'mail') ? $this->newline : '';
@@ -1332,7 +1280,7 @@ class CI_Email {
 
 		switch ($this->_get_content_type())
 		{
-			case 'plain' :
+			case 'plain':
 
 				$hdr .= 'Content-Type: text/plain; charset='.$this->charset.$this->newline
 					.'Content-Transfer-Encoding: '.$this->_get_encoding();
@@ -1349,7 +1297,7 @@ class CI_Email {
 
 				return;
 
-			case 'html' :
+			case 'html':
 
 				if ($this->send_multipart === FALSE)
 				{
@@ -1358,14 +1306,16 @@ class CI_Email {
 				}
 				else
 				{
-					$hdr .= 'Content-Type: multipart/alternative; boundary="'.$this->_alt_boundary.'"';
+					$boundary = uniqid('B_ALT_');
+					$hdr .= 'Content-Type: multipart/alternative; boundary="'.$boundary.'"';
 
 					$body .= $this->_get_mime_message().$this->newline.$this->newline
-						.'--'.$this->_alt_boundary.$this->newline
+						.'--'.$boundary.$this->newline
 
 						.'Content-Type: text/plain; charset='.$this->charset.$this->newline
 						.'Content-Transfer-Encoding: '.$this->_get_encoding().$this->newline.$this->newline
-						.$this->_get_alt_message().$this->newline.$this->newline.'--'.$this->_alt_boundary.$this->newline
+						.$this->_get_alt_message().$this->newline.$this->newline
+						.'--'.$boundary.$this->newline
 
 						.'Content-Type: text/html; charset='.$this->charset.$this->newline
 						.'Content-Transfer-Encoding: quoted-printable'.$this->newline.$this->newline;
@@ -1384,14 +1334,15 @@ class CI_Email {
 
 				if ($this->send_multipart !== FALSE)
 				{
-					$this->_finalbody .= '--'.$this->_alt_boundary.'--';
+					$this->_finalbody .= '--'.$boundary.'--';
 				}
 
 				return;
 
-			case 'plain-attach' :
+			case 'plain-attach':
 
-				$hdr .= 'Content-Type: multipart/'.$this->multipart.'; boundary="'.$this->_atc_boundary.'"';
+				$boundary = uniqid('B_ATC_');
+				$hdr .= 'Content-Type: multipart/mixed; boundary="'.$boundary.'"';
 
 				if ($this->_get_protocol() === 'mail')
 				{
@@ -1400,59 +1351,83 @@ class CI_Email {
 
 				$body .= $this->_get_mime_message().$this->newline
 					.$this->newline
-					.'--'.$this->_atc_boundary.$this->newline
+					.'--'.$boundary.$this->newline
 					.'Content-Type: text/plain; charset='.$this->charset.$this->newline
 					.'Content-Transfer-Encoding: '.$this->_get_encoding().$this->newline
 					.$this->newline
 					.$this->_body.$this->newline.$this->newline;
 
-			break;
-			case 'html-attach' :
+				$this->_append_attachments($body, $boundary);
 
-				$hdr .= 'Content-Type: multipart/'.$this->multipart.'; boundary="'.$this->_atc_boundary.'"';
+				break;
+			case 'html-attach':
+
+				$alt_boundary = uniqid('B_ALT_');
+				$last_boundary = NULL;
+
+				if ($this->_attachments_have_multipart('mixed'))
+				{
+					$atc_boundary = uniqid('B_ATC_');
+					$hdr .= 'Content-Type: multipart/mixed; boundary="'.$atc_boundary.'"';
+					$last_boundary = $atc_boundary;
+				}
+
+				if ($this->_attachments_have_multipart('related'))
+				{
+					$rel_boundary = uniqid('B_REL_');
+					$rel_boundary_header = 'Content-Type: multipart/related; boundary="'.$rel_boundary.'"';
+
+					if (isset($last_boundary))
+					{
+						$body .= '--'.$last_boundary.$this->newline.$rel_boundary_header;
+					}
+					else
+					{
+						$hdr .= $rel_boundary_header;
+					}
+
+					$last_boundary = $rel_boundary;
+				}
 
 				if ($this->_get_protocol() === 'mail')
 				{
 					$this->_header_str .= $hdr;
 				}
 
+				self::strlen($body) && $body .= $this->newline.$this->newline;
 				$body .= $this->_get_mime_message().$this->newline.$this->newline
-					.'--'.$this->_atc_boundary.$this->newline
+					.'--'.$last_boundary.$this->newline
 
-					.'Content-Type: multipart/alternative; boundary="'.$this->_alt_boundary.'"'.$this->newline.$this->newline
-					.'--'.$this->_alt_boundary.$this->newline
+					.'Content-Type: multipart/alternative; boundary="'.$alt_boundary.'"'.$this->newline.$this->newline
+					.'--'.$alt_boundary.$this->newline
 
 					.'Content-Type: text/plain; charset='.$this->charset.$this->newline
 					.'Content-Transfer-Encoding: '.$this->_get_encoding().$this->newline.$this->newline
-					.$this->_get_alt_message().$this->newline.$this->newline.'--'.$this->_alt_boundary.$this->newline
+					.$this->_get_alt_message().$this->newline.$this->newline
+					.'--'.$alt_boundary.$this->newline
 
 					.'Content-Type: text/html; charset='.$this->charset.$this->newline
 					.'Content-Transfer-Encoding: quoted-printable'.$this->newline.$this->newline
 
 					.$this->_prep_quoted_printable($this->_body).$this->newline.$this->newline
-					.'--'.$this->_alt_boundary.'--'.$this->newline.$this->newline;
+					.'--'.$alt_boundary.'--'.$this->newline.$this->newline;
 
-			break;
+				if ( ! empty($rel_boundary))
+				{
+					$body .= $this->newline.$this->newline;
+					$this->_append_attachments($body, $rel_boundary, 'related');
+				}
+
+				// multipart/mixed attachments
+				if ( ! empty($atc_boundary))
+				{
+					$body .= $this->newline.$this->newline;
+					$this->_append_attachments($body, $atc_boundary, 'mixed');
+				}
+
+				break;
 		}
 
-		$attachment = array();
-		for ($i = 0, $c = count($this->_attachments), $z = 0; $i < $c; $i++)
-		{
-			$filename = $this->_attachments[$i]['name'][0];
-			$basename = ($this->_attachments[$i]['name'][1] === NULL)
-				? basename($filename) : $this->_attachments[$i]['name'][1];
-
-			$attachment[$z++] = '--'.$this->_atc_boundary.$this->newline
-				.'Content-type: '.$this->_attachments[$i]['type'].'; '
-				.'name="'.$basename.'"'.$this->newline
-				.'Content-Disposition: '.$this->_attachments[$i]['disposition'].';'.$this->newline
-				.'Content-Transfer-Encoding: base64'.$this->newline
-				.(empty($this->_attachments[$i]['cid']) ? '' : 'Content-ID: <'.$this->_attachments[$i]['cid'].'>'.$this->newline);
-
-			$attachment[$z++] = $this->_attachments[$i]['content'];
-		}
-
-		$body .= implode($this->newline, $attachment).$this->newline.'--'.$this->_atc_boundary.'--';
 		$this->_finalbody = ($this->_get_protocol() === 'mail')
 			? $body
 			: $hdr.$this->newline.$this->newline.$body;
@@ -1462,6 +1437,58 @@ class CI_Email {
 
 	// --------------------------------------------------------------------
 
+	protected function _attachments_have_multipart($type)
+	{
+		foreach ($this->_attachments as &$attachment)
+		{
+			if ($attachment['multipart'] === $type)
+			{
+				return TRUE;
+			}
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Prepares attachment string
+	 *
+	 * @param	string	$body		Message body to append to
+	 * @param	string	$boundary	Multipart boundary
+	 * @param	string	$multipart	When provided, only attachments of this type will be processed
+	 * @return	string
+	 */
+	protected function _append_attachments(&$body, $boundary, $multipart = null)
+	{
+		for ($i = 0, $c = count($this->_attachments); $i < $c; $i++)
+		{
+			if (isset($multipart) && $this->_attachments[$i]['multipart'] !== $multipart)
+			{
+				continue;
+			}
+
+			$name = isset($this->_attachments[$i]['name'][1])
+				? $this->_attachments[$i]['name'][1]
+				: basename($this->_attachments[$i]['name'][0]);
+
+			$body .= '--'.$boundary.$this->newline
+				.'Content-Type: '.$this->_attachments[$i]['type'].'; name="'.$name.'"'.$this->newline
+				.'Content-Disposition: '.$this->_attachments[$i]['disposition'].';'.$this->newline
+				.'Content-Transfer-Encoding: base64'.$this->newline
+				.(empty($this->_attachments[$i]['cid']) ? '' : 'Content-ID: <'.$this->_attachments[$i]['cid'].'>'.$this->newline)
+				.$this->newline
+				.$this->_attachments[$i]['content'].$this->newline;
+		}
+
+		// $name won't be set if no attachments were appended,
+		// and therefore a boundary wouldn't be necessary
+		empty($name) OR $body .= '--'.$boundary.'--';
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Prep Quoted Printable
 	 *
@@ -1497,14 +1524,7 @@ class CI_Email {
 		// which only works with "\n".
 		if ($this->crlf === "\r\n")
 		{
-			if (is_php('5.3'))
-			{
-				return quoted_printable_encode($str);
-			}
-			elseif (function_exists('imap_8bit'))
-			{
-				return imap_8bit($str);
-			}
+			return quoted_printable_encode($str);
 		}
 
 		// Reduce multiple spaces & remove nulls
@@ -1521,7 +1541,7 @@ class CI_Email {
 
 		foreach (explode("\n", $str) as $line)
 		{
-			$length = strlen($line);
+			$length = self::strlen($line);
 			$temp = '';
 
 			// Loop through each character in the line to add soft-wrap
@@ -1556,7 +1576,7 @@ class CI_Email {
 
 				// If we're at the character limit, add the line to the output,
 				// reset our temp variable, and keep on chuggin'
-				if ((strlen($temp) + strlen($char)) >= 76)
+				if ((self::strlen($temp) + self::strlen($char)) >= 76)
 				{
 					$output .= $temp.$escape.$this->crlf;
 					$temp = '';
@@ -1571,7 +1591,7 @@ class CI_Email {
 		}
 
 		// get rid of extra CRLF tacked onto the end
-		return substr($output, 0, strlen($this->crlf) * -1);
+		return self::substr($output, 0, self::strlen($this->crlf) * -1);
 	}
 
 	// --------------------------------------------------------------------
@@ -1613,7 +1633,7 @@ class CI_Email {
 					// iconv_mime_encode() will always put a header field name.
 					// We've passed it an empty one, but it still prepends our
 					// encoded string with ': ', so we need to strip it.
-					return substr($output, 2);
+					return self::substr($output, 2);
 				}
 
 				$chars = iconv_strlen($str, 'UTF-8');
@@ -1625,10 +1645,10 @@ class CI_Email {
 		}
 
 		// We might already have this set for UTF-8
-		isset($chars) OR $chars = strlen($str);
+		isset($chars) OR $chars = self::strlen($str);
 
 		$output = '=?'.$this->charset.'?Q?';
-		for ($i = 0, $length = strlen($output); $i < $chars; $i++)
+		for ($i = 0, $length = self::strlen($output); $i < $chars; $i++)
 		{
 			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === TRUE)
 				? '='.implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2))
@@ -1636,11 +1656,11 @@ class CI_Email {
 
 			// RFC 2045 sets a limit of 76 characters per line.
 			// We'll append ?= to the end of each line though.
-			if ($length + ($l = strlen($chr)) > 74)
+			if ($length + ($l = self::strlen($chr)) > 74)
 			{
 				$output .= '?='.$this->crlf // EOL
 					.' =?'.$this->charset.'?Q?'.$chr; // New line
-				$length = 6 + strlen($this->charset) + $l; // Reset the length for the new line
+				$length = 6 + self::strlen($this->charset) + $l; // Reset the length for the new line
 			}
 			else
 			{
@@ -1733,14 +1753,14 @@ class CI_Email {
 
 			if ($i === $float)
 			{
-				$chunk[] = substr($set, 1);
+				$chunk[] = self::substr($set, 1);
 				$float += $this->bcc_batch_size;
 				$set = '';
 			}
 
 			if ($i === $c-1)
 			{
-				$chunk[] = substr($set, 1);
+				$chunk[] = self::substr($set, 1);
 			}
 		}
 
@@ -1822,6 +1842,33 @@ class CI_Email {
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * Validate email for shell
+	 *
+	 * Applies stricter, shell-safe validation to email addresses.
+	 * Introduced to prevent RCE via sendmail's -f option.
+	 *
+	 * @see	https://github.com/bcit-ci/CodeIgniter/issues/4963
+	 * @see	https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
+	 * @license	https://creativecommons.org/publicdomain/zero/1.0/	CC0 1.0, Public Domain
+	 *
+	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
+	 *
+	 * @param	string	$email
+	 * @return	bool
+	 */
+	protected function _validate_email_for_shell(&$email)
+	{
+		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
+		{
+			$email = self::substr($email, 0, ++$atpos).idn_to_ascii(self::substr($email, $atpos));
+		}
+
+		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Send using mail()
 	 *
@@ -1834,7 +1881,11 @@ class CI_Email {
 			$this->_recipients = implode(', ', $this->_recipients);
 		}
 
-		if ($this->_safe_mode === TRUE)
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->clean_email($this->_headers['Return-Path']);
+
+		if ($this->_safe_mode === TRUE || ! $this->_validate_email_for_shell($from))
 		{
 			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str);
 		}
@@ -1842,7 +1893,7 @@ class CI_Email {
 		{
 			// most documentation of sendmail using the "-f" flag lacks a space after it, however
 			// we've encountered servers that seem to require it to be in place.
-			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$this->clean_email($this->_headers['Return-Path']));
+			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$from);
 		}
 	}
 
@@ -1855,13 +1906,22 @@ class CI_Email {
 	 */
 	protected function _send_with_sendmail()
 	{
-		// is popen() enabled?
-		if ( ! function_usable('popen')
-			OR FALSE === ($fp = @popen(
-						$this->mailpath.' -oi -f '.$this->clean_email($this->_headers['From']).' -t'
-						, 'w'))
-		) // server probably has popen disabled, so nothing we can do to get a verbose error.
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->clean_email($this->_headers['From']);
+		if ($this->_validate_email_for_shell($from))
 		{
+			$from = '-f '.$from;
+		}
+		else
+		{
+			$from = '';
+		}
+
+		// is popen() enabled?
+		if ( ! function_usable('popen')	OR FALSE === ($fp = @popen($this->mailpath.' -oi '.$from.' -t', 'w')))
+		{
+			// server probably has popen disabled, so nothing we can do to get a verbose error.
 			return FALSE;
 		}
 
@@ -1902,6 +1962,7 @@ class CI_Email {
 
 		if ( ! $this->_send_command('from', $this->clean_email($this->_headers['From'])))
 		{
+			$this->_smtp_end();
 			return FALSE;
 		}
 
@@ -1909,6 +1970,7 @@ class CI_Email {
 		{
 			if ( ! $this->_send_command('to', $val))
 			{
+				$this->_smtp_end();
 				return FALSE;
 			}
 		}
@@ -1919,6 +1981,7 @@ class CI_Email {
 			{
 				if ($val !== '' && ! $this->_send_command('to', $val))
 				{
+					$this->_smtp_end();
 					return FALSE;
 				}
 			}
@@ -1930,6 +1993,7 @@ class CI_Email {
 			{
 				if ($val !== '' && ! $this->_send_command('to', $val))
 				{
+					$this->_smtp_end();
 					return FALSE;
 				}
 			}
@@ -1937,6 +2001,7 @@ class CI_Email {
 
 		if ( ! $this->_send_command('data'))
 		{
+			$this->_smtp_end();
 			return FALSE;
 		}
 
@@ -1946,29 +2011,37 @@ class CI_Email {
 		$this->_send_data('.');
 
 		$reply = $this->_get_smtp_data();
-
 		$this->_set_error_message($reply);
 
+		$this->_smtp_end();
+
 		if (strpos($reply, '250') !== 0)
 		{
 			$this->_set_error_message('lang:email_smtp_error', $reply);
 			return FALSE;
 		}
 
-		if ($this->smtp_keepalive)
-		{
-			$this->_send_command('reset');
-		}
-		else
-		{
-			$this->_send_command('quit');
-		}
-
 		return TRUE;
 	}
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * SMTP End
+	 *
+	 * Shortcut to send RSET or QUIT depending on keep-alive
+	 *
+	 * @return	void
+	 */
+	protected function _smtp_end()
+	{
+		($this->smtp_keepalive)
+			? $this->_send_command('reset')
+			: $this->_send_command('quit');
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * SMTP Connect
 	 *
@@ -2022,7 +2095,7 @@ class CI_Email {
 	 *
 	 * @param	string
 	 * @param	string
-	 * @return	string
+	 * @return	bool
 	 */
 	protected function _send_command($cmd, $data = '')
 	{
@@ -2085,7 +2158,7 @@ class CI_Email {
 
 		$this->_debug_msg[] = '<pre>'.$cmd.': '.$reply.'</pre>';
 
-		if ((int) substr($reply, 0, 3) !== $resp)
+		if ((int) self::substr($reply, 0, 3) !== $resp)
 		{
 			$this->_set_error_message('lang:email_smtp_error', $reply);
 			return FALSE;
@@ -2153,6 +2226,11 @@ class CI_Email {
 			return FALSE;
 		}
 
+		if ($this->smtp_keepalive)
+		{
+			$this->_smtp_auth = FALSE;
+		}
+
 		return TRUE;
 	}
 
@@ -2167,9 +2245,9 @@ class CI_Email {
 	protected function _send_data($data)
 	{
 		$data .= $this->newline;
-		for ($written = $timestamp = 0, $length = strlen($data); $written < $length; $written += $result)
+		for ($written = $timestamp = 0, $length = self::strlen($data); $written < $length; $written += $result)
 		{
-			if (($result = fwrite($this->_smtp_connect, substr($data, $written))) === FALSE)
+			if (($result = fwrite($this->_smtp_connect, self::substr($data, $written))) === FALSE)
 			{
 				break;
 			}
@@ -2342,4 +2420,55 @@ class CI_Email {
 		return 'application/x-unknown-content-type';
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Destructor
+	 *
+	 * @return	void
+	 */
+	public function __destruct()
+	{
+		is_resource($this->_smtp_connect) && $this->_send_command('quit');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return (self::$func_overload)
+			? mb_strlen($str, '8bit')
+			: strlen($str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param	string	$str
+	 * @param	int	$start
+	 * @param	int	$length
+	 * @return	string
+	 */
+	protected static function substr($str, $start, $length = NULL)
+	{
+		if (self::$func_overload)
+		{
+			// mb_substr($str, $start, null, '8bit') returns an empty
+			// string on PHP 5.3
+			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length)
+			? substr($str, $start, $length)
+			: substr($str, $start);
+	}
 }
diff --git a/src/system/libraries/Encrypt.php b/src/system/libraries/Encrypt.php
index 1372a311..ebcc6e8c 100644
--- a/src/system/libraries/Encrypt.php
+++ b/src/system/libraries/Encrypt.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -122,7 +122,7 @@ class CI_Encrypt {
 
 			$key = config_item('encryption_key');
 
-			if ( ! strlen($key))
+			if ( ! self::strlen($key))
 			{
 				show_error('In order to use the encryption class requires that you set an encryption key in your config file.');
 			}
@@ -252,7 +252,7 @@ class CI_Encrypt {
 		$string = $this->_xor_merge($string, $key);
 
 		$dec = '';
-		for ($i = 0, $l = strlen($string); $i < $l; $i++)
+		for ($i = 0, $l = self::strlen($string); $i < $l; $i++)
 		{
 			$dec .= ($string[$i++] ^ $string[$i]);
 		}
@@ -275,7 +275,8 @@ class CI_Encrypt {
 	{
 		$hash = $this->hash($key);
 		$str = '';
-		for ($i = 0, $ls = strlen($string), $lh = strlen($hash); $i < $ls; $i++)
+
+		for ($i = 0, $ls = self::strlen($string), $lh = self::strlen($hash); $i < $ls; $i++)
 		{
 			$str .= $string[$i] ^ $hash[($i % $lh)];
 		}
@@ -295,7 +296,7 @@ class CI_Encrypt {
 	public function mcrypt_encode($data, $key)
 	{
 		$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
-		$init_vect = mcrypt_create_iv($init_size, MCRYPT_RAND);
+		$init_vect = mcrypt_create_iv($init_size, MCRYPT_DEV_URANDOM);
 		return $this->_add_cipher_noise($init_vect.mcrypt_encrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), $key);
 	}
 
@@ -313,13 +314,14 @@ class CI_Encrypt {
 		$data = $this->_remove_cipher_noise($data, $key);
 		$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
 
-		if ($init_size > strlen($data))
+		if ($init_size > self::strlen($data))
 		{
 			return FALSE;
 		}
 
-		$init_vect = substr($data, 0, $init_size);
-		$data = substr($data, $init_size);
+		$init_vect = self::substr($data, 0, $init_size);
+		$data      = self::substr($data, $init_size);
+
 		return rtrim(mcrypt_decrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), "\0");
 	}
 
@@ -339,7 +341,7 @@ class CI_Encrypt {
 		$key = $this->hash($key);
 		$str = '';
 
-		for ($i = 0, $j = 0, $ld = strlen($data), $lk = strlen($key); $i < $ld; ++$i, ++$j)
+		for ($i = 0, $j = 0, $ld = self::strlen($data), $lk = self::strlen($key); $i < $ld; ++$i, ++$j)
 		{
 			if ($j >= $lk)
 			{
@@ -369,7 +371,7 @@ class CI_Encrypt {
 		$key = $this->hash($key);
 		$str = '';
 
-		for ($i = 0, $j = 0, $ld = strlen($data), $lk = strlen($key); $i < $ld; ++$i, ++$j)
+		for ($i = 0, $j = 0, $ld = self::strlen($data), $lk = self::strlen($key); $i < $ld; ++$i, ++$j)
 		{
 			if ($j >= $lk)
 			{
@@ -477,4 +479,43 @@ class CI_Encrypt {
 		return hash($this->_hash_type, $str);
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return defined('MB_OVERLOAD_STRING')
+			? mb_strlen($str, '8bit')
+			: strlen($str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param	string	$str
+	 * @param	int	$start
+	 * @param	int	$length
+	 * @return	string
+	 */
+	protected static function substr($str, $start, $length = NULL)
+	{
+		if (defined('MB_OVERLOAD_STRING'))
+		{
+			// mb_substr($str, $start, null, '8bit') returns an empty
+			// string on PHP 5.3
+			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length)
+			? substr($str, $start, $length)
+			: substr($str, $start);
+	}
 }
diff --git a/src/system/libraries/Encryption.php b/src/system/libraries/Encryption.php
index 92c38a0e..c1e454dd 100644
--- a/src/system/libraries/Encryption.php
+++ b/src/system/libraries/Encryption.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -135,11 +135,11 @@ class CI_Encryption {
 	);
 
 	/**
-	 * mbstring.func_override flag
+	 * mbstring.func_overload flag
 	 *
 	 * @var	bool
 	 */
-	protected static $func_override;
+	protected static $func_overload;
 
 	// --------------------------------------------------------------------
 
@@ -152,10 +152,8 @@ class CI_Encryption {
 	public function __construct(array $params = array())
 	{
 		$this->_drivers = array(
-			'mcrypt' => defined('MCRYPT_DEV_URANDOM'),
-			// While OpenSSL is available for PHP 5.3.0, an IV parameter
-			// for the encrypt/decrypt functions is only available since 5.3.3
-			'openssl' => (is_php('5.3.3') && extension_loaded('openssl'))
+			'mcrypt'  => defined('MCRYPT_DEV_URANDOM'),
+			'openssl' => extension_loaded('openssl')
 		);
 
 		if ( ! $this->_drivers['mcrypt'] && ! $this->_drivers['openssl'])
@@ -163,7 +161,7 @@ class CI_Encryption {
 			show_error('Encryption: Unable to find an available encryption driver.');
 		}
 
-		isset(self::$func_override) OR self::$func_override = (extension_loaded('mbstring') && ini_get('mbstring.func_override'));
+		isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
 		$this->initialize($params);
 
 		if ( ! isset($this->_key) && self::strlen($key = config_item('encryption_key')) > 0)
@@ -339,12 +337,26 @@ class CI_Encryption {
 	{
 		if (function_exists('random_bytes'))
 		{
-			return random_bytes((int) $length);
+			try
+			{
+				return random_bytes((int) $length);
+			}
+			catch (Exception $e)
+			{
+				log_message('error', $e->getMessage());
+				return FALSE;
+			}
+		}
+		elseif (defined('MCRYPT_DEV_URANDOM'))
+		{
+			return mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
 		}
 
-		return ($this->_driver === 'mcrypt')
-			? mcrypt_create_iv($length, MCRYPT_DEV_URANDOM)
-			: openssl_random_pseudo_bytes($length);
+		$is_secure = NULL;
+		$key = openssl_random_pseudo_bytes($length, $is_secure);
+		return ($is_secure === TRUE)
+			? $key
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -400,7 +412,7 @@ class CI_Encryption {
 		// The greater-than-1 comparison is mostly a work-around for a bug,
 		// where 1 is returned for ARCFour instead of 0.
 		$iv = (($iv_size = mcrypt_enc_get_iv_size($params['handle'])) > 1)
-			? mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM)
+			? $this->create_key($iv_size)
 			: NULL;
 
 		if (mcrypt_generic_init($params['handle'], $params['key'], $iv) < 0)
@@ -463,7 +475,7 @@ class CI_Encryption {
 		}
 
 		$iv = ($iv_size = openssl_cipher_iv_length($params['handle']))
-			? openssl_random_pseudo_bytes($iv_size)
+			? $this->create_key($iv_size)
 			: NULL;
 
 		$data = openssl_encrypt(
@@ -895,11 +907,11 @@ class CI_Encryption {
 	 * Byte-safe strlen()
 	 *
 	 * @param	string	$str
-	 * @return	integer
+	 * @return	int
 	 */
 	protected static function strlen($str)
 	{
-		return (self::$func_override)
+		return (self::$func_overload)
 			? mb_strlen($str, '8bit')
 			: strlen($str);
 	}
@@ -916,7 +928,7 @@ class CI_Encryption {
 	 */
 	protected static function substr($str, $start, $length = NULL)
 	{
-		if (self::$func_override)
+		if (self::$func_overload)
 		{
 			// mb_substr($str, $start, null, '8bit') returns an empty
 			// string on PHP 5.3
diff --git a/src/system/libraries/Form_validation.php b/src/system/libraries/Form_validation.php
index e4a51895..4f679a17 100644
--- a/src/system/libraries/Form_validation.php
+++ b/src/system/libraries/Form_validation.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -493,6 +493,63 @@ class CI_Form_validation {
 
 	// --------------------------------------------------------------------
 
+	/**
+	 * Prepare rules
+	 *
+	 * Re-orders the provided rules in order of importance, so that
+	 * they can easily be executed later without weird checks ...
+	 *
+	 * "Callbacks" are given the highest priority (always called),
+	 * followed by 'required' (called if callbacks didn't fail),
+	 * and then every next rule depends on the previous one passing.
+	 *
+	 * @param	array	$rules
+	 * @return	array
+	 */
+	protected function _prepare_rules($rules)
+	{
+		$new_rules = array();
+		$callbacks = array();
+
+		foreach ($rules as &$rule)
+		{
+			// Let 'required' always be the first (non-callback) rule
+			if ($rule === 'required')
+			{
+				array_unshift($new_rules, 'required');
+			}
+			// 'isset' is a kind of a weird alias for 'required' ...
+			elseif ($rule === 'isset' && (empty($new_rules) OR $new_rules[0] !== 'required'))
+			{
+				array_unshift($new_rules, 'isset');
+			}
+			// The old/classic 'callback_'-prefixed rules
+			elseif (is_string($rule) && strncmp('callback_', $rule, 9) === 0)
+			{
+				$callbacks[] = $rule;
+			}
+			// Proper callables
+			elseif (is_callable($rule))
+			{
+				$callbacks[] = $rule;
+			}
+			// "Named" callables; i.e. array('name' => $callable)
+			elseif (is_array($rule) && isset($rule[0], $rule[1]) && is_callable($rule[1]))
+			{
+				$callbacks[] = $rule;
+			}
+			// Everything else goes at the end of the queue
+			else
+			{
+				$new_rules[] = $rule;
+			}
+		}
+
+		return array_merge($callbacks, $new_rules);
+	}
+
+	// --------------------------------------------------------------------
+
 	/**
 	 * Traverse a multidimensional $_POST array index until the data is found
 	 *
@@ -580,70 +637,7 @@ class CI_Form_validation {
 			return;
 		}
 
-		// If the field is blank, but NOT required, no further tests are necessary
-		$callback = FALSE;
-		if ( ! in_array('required', $rules) && ($postdata === NULL OR $postdata === ''))
-		{
-			// Before we bail out, does the rule contain a callback?
-			foreach ($rules as &$rule)
-			{
-				if (is_string($rule))
-				{
-					if (strncmp($rule, 'callback_', 9) === 0)
-					{
-						$callback = TRUE;
-						$rules = array(1 => $rule);
-						break;
-					}
-				}
-				elseif (is_callable($rule))
-				{
-					$callback = TRUE;
-					$rules = array(1 => $rule);
-					break;
-				}
-				elseif (is_array($rule) && isset($rule[0], $rule[1]) && is_callable($rule[1]))
-				{
-					$callback = TRUE;
-					$rules = array(array($rule[0], $rule[1]));
-					break;
-				}
-			}
-
-			if ( ! $callback)
-			{
-				return;
-			}
-		}
-
-		// Isset Test. Typically this rule will only apply to checkboxes.
-		if (($postdata === NULL OR $postdata === '') && ! $callback)
-		{
-			if (in_array('isset', $rules, TRUE) OR in_array('required', $rules))
-			{
-				// Set the message type
-				$type = in_array('required', $rules) ? 'required' : 'isset';
-
-				$line = $this->_get_error_message($type, $row['field']);
-
-				// Build the error message
-				$message = $this->_build_error_msg($line, $this->_translate_fieldname($row['label']));
-
-				// Save the error message
-				$this->_field_data[$row['field']]['error'] = $message;
-
-				if ( ! isset($this->_error_array[$row['field']]))
-				{
-					$this->_error_array[$row['field']] = $message;
-				}
-			}
-
-			return;
-		}
-
-		// --------------------------------------------------------------------
-
-		// Cycle through each rule and run it
+		$rules = $this->_prepare_rules($rules);
 		foreach ($rules as $rule)
 		{
 			$_in_array = FALSE;
@@ -702,6 +696,17 @@ class CI_Form_validation {
 				$param = $match[2];
 			}
 
+			// Ignore empty, non-required inputs with a few exceptions ...
+			if (
+				($postdata === NULL OR $postdata === '')
+				&& $callback === FALSE
+				&& $callable === FALSE
+				&& ! in_array($rule, array('required', 'isset', 'matches'), TRUE)
+			)
+			{
+				continue;
+			}
+
 			// Call the function that corresponds to the rule
 			if ($callback OR $callable !== FALSE)
 			{
@@ -740,12 +745,6 @@ class CI_Form_validation {
 				{
 					$this->_field_data[$row['field']]['postdata'] = is_bool($result) ? $postdata : $result;
 				}
-
-				// If the field isn't required and we just processed a callback we'll move on...
-				if ( ! in_array('required', $rules, TRUE) && $result !== FALSE)
-				{
-					continue;
-				}
 			}
 			elseif ( ! method_exists($this, $rule))
 			{
@@ -1055,7 +1054,9 @@ class CI_Form_validation {
 	 */
 	public function required($str)
 	{
-		return is_array($str) ? (bool) count($str) : (trim($str) !== '');
+		return is_array($str)
+			? (empty($str) === FALSE)
+			: (trim($str) !== '');
 	}
 
 	// --------------------------------------------------------------------
@@ -1199,7 +1200,7 @@ class CI_Form_validation {
 			{
 				return FALSE;
 			}
-			elseif ( ! in_array($matches[1], array('http', 'https'), TRUE))
+			elseif ( ! in_array(strtolower($matches[1]), array('http', 'https'), TRUE))
 			{
 				return FALSE;
 			}
@@ -1215,18 +1216,7 @@ class CI_Form_validation {
 			$str = 'ipv6.host'.substr($str, strlen($matches[1]) + 2);
 		}
 
-		$str = 'http://'.$str;
-
-		// There's a bug affecting PHP 5.2.13, 5.3.2 that considers the
-		// underscore to be a valid hostname character instead of a dash.
-		// Reference: https://bugs.php.net/bug.php?id=51192
-		if (version_compare(PHP_VERSION, '5.2.13', '==') OR version_compare(PHP_VERSION, '5.3.2', '=='))
-		{
-			sscanf($str, 'http://%[^/]', $host);
-			$str = substr_replace($str, strtr($host, array('_' => '-', '-' => '_')), 7, strlen($host));
-		}
-
-		return (filter_var($str, FILTER_VALIDATE_URL) !== FALSE);
+		return (filter_var('http://'.$str, FILTER_VALIDATE_URL) !== FALSE);
 	}
 
 	// --------------------------------------------------------------------
@@ -1239,9 +1229,9 @@ class CI_Form_validation {
 	 */
 	public function valid_email($str)
 	{
-		if (function_exists('idn_to_ascii') && $atpos = strpos($str, '@'))
+		if (function_exists('idn_to_ascii') && sscanf($str, '%[^@]@%s', $name, $domain) === 2)
 		{
-			$str = substr($str, 0, ++$atpos).idn_to_ascii(substr($str, $atpos));
+			$str = $name.'@'.idn_to_ascii($domain);
 		}
 
 		return (bool) filter_var($str, FILTER_VALIDATE_EMAIL);
diff --git a/src/system/libraries/Ftp.php b/src/system/libraries/Ftp.php
index 88f26580..86e5b8f3 100644
--- a/src/system/libraries/Ftp.php
+++ b/src/system/libraries/Ftp.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -486,7 +486,7 @@ class CI_FTP {
 		{
 			for ($i = 0, $c = count($list); $i < $c; $i++)
 			{
-				// If we can't delete the item it's probaly a directory,
+				// If we can't delete the item it's probably a directory,
 				// so we'll recursively call delete_dir()
 				if ( ! preg_match('#/\.\.?$#', $list[$i]) && ! @ftp_delete($this->conn_id, $list[$i]))
 				{
diff --git a/src/system/libraries/Image_lib.php b/src/system/libraries/Image_lib.php
index f594b712..88c9e7ed 100644
--- a/src/system/libraries/Image_lib.php
+++ b/src/system/libraries/Image_lib.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -392,6 +392,16 @@ class CI_Image_lib {
 			$this->initialize($props);
 		}
 
+		/**
+		 * A work-around for some improperly formatted, but
+		 * usable JPEGs; known to be produced by Samsung
+		 * smartphones' front-facing cameras.
+		 *
+		 * @see	https://github.com/bcit-ci/CodeIgniter/issues/4967
+		 * @see	https://bugs.php.net/bug.php?id=72404
+		 */
+		ini_set('gd.jpeg_ignore_warning', 1);
+
 		log_message('info', 'Image Lib Class Initialized');
 	}
 
@@ -456,7 +466,7 @@ class CI_Image_lib {
 			{
 				if (property_exists($this, $key))
 				{
-					if (in_array($key, array('wm_font_color', 'wm_shadow_color')))
+					if (in_array($key, array('wm_font_color', 'wm_shadow_color'), TRUE))
 					{
 						if (preg_match('/^#?([0-9a-f]{3}|[0-9a-f]{6})$/i', $val, $matches))
 						{
@@ -478,6 +488,10 @@ class CI_Image_lib {
 							continue;
 						}
 					}
+					elseif (in_array($key, array('width', 'height'), TRUE) && ! ctype_digit((string) $val))
+					{
+						continue;
+					}
 
 					$this->$key = $val;
 				}
@@ -540,37 +554,30 @@ class CI_Image_lib {
 		 */
 		if ($this->new_image === '')
 		{
-			$this->dest_image = $this->source_image;
+			$this->dest_image  = $this->source_image;
 			$this->dest_folder = $this->source_folder;
 		}
-		elseif (strpos($this->new_image, '/') === FALSE)
+		elseif (strpos($this->new_image, '/') === FALSE && strpos($this->new_image, '\\') === FALSE)
 		{
+			$this->dest_image  = $this->new_image;
 			$this->dest_folder = $this->source_folder;
-			$this->dest_image = $this->new_image;
 		}
 		else
 		{
-			if (strpos($this->new_image, '/') === FALSE && strpos($this->new_image, '\\') === FALSE)
+			// Is there a file name?
+			if ( ! preg_match('#\.(jpg|jpeg|gif|png)$#i', $this->new_image))
 			{
-				$full_dest_path = str_replace('\\', '/', realpath($this->new_image));
+				$this->dest_image  = $this->source_image;
+				$this->dest_folder = $this->new_image;
 			}
 			else
 			{
-				$full_dest_path = $this->new_image;
+				$x = explode('/', str_replace('\\', '/', $this->new_image));
+				$this->dest_image  = end($x);
+				$this->dest_folder = str_replace($this->dest_image, '', $this->new_image);
 			}
 
-			// Is there a file name?
-			if ( ! preg_match('#\.(jpg|jpeg|gif|png)$#i', $full_dest_path))
-			{
-				$this->dest_folder = $full_dest_path.'/';
-				$this->dest_image = $this->source_image;
-			}
-			else
-			{
-				$x = explode('/', $full_dest_path);
-				$this->dest_image = end($x);
-				$this->dest_folder = str_replace($this->dest_image, '', $full_dest_path);
-			}
+			$this->dest_folder = realpath($this->dest_folder).'/';
 		}
 
 		/* Compile the finalized filenames/paths
@@ -862,27 +869,28 @@ class CI_Image_lib {
 
 		if ($action === 'crop')
 		{
-			$cmd .= ' -crop '.$this->width.'x'.$this->height.'+'.$this->x_axis.'+'.$this->y_axis.' "'.$this->full_src_path.'" "'.$this->full_dst_path .'" 2>&1';
+			$cmd .= ' -crop '.$this->width.'x'.$this->height.'+'.$this->x_axis.'+'.$this->y_axis;
 		}
 		elseif ($action === 'rotate')
 		{
-			$angle = ($this->rotation_angle === 'hor' OR $this->rotation_angle === 'vrt')
-					? '-flop' : '-rotate '.$this->rotation_angle;
-
-			$cmd .= ' '.$angle.' "'.$this->full_src_path.'" "'.$this->full_dst_path.'" 2>&1';
+			$cmd .= ($this->rotation_angle === 'hor' OR $this->rotation_angle === 'vrt')
+					? ' -flop'
+					: ' -rotate '.$this->rotation_angle;
 		}
 		else // Resize
 		{
 			if($this->maintain_ratio === TRUE)
 			{
-				$cmd .= ' -resize '.$this->width.'x'.$this->height.' "'.$this->full_src_path.'" "'.$this->full_dst_path.'" 2>&1';
+				$cmd .= ' -resize '.$this->width.'x'.$this->height;
 			}
 			else
 			{
-				$cmd .= ' -resize '.$this->width.'x'.$this->height.'\! "'.$this->full_src_path.'" "'.$this->full_dst_path.'" 2>&1';
+				$cmd .= ' -resize '.$this->width.'x'.$this->height.'\!';
 			}
 		}
 
+		$cmd .= ' '.escapeshellarg($this->full_src_path).' '.escapeshellarg($this->full_dst_path).' 2>&1';
+
 		$retval = 1;
 		// exec() might be disabled
 		if (function_usable('exec'))
@@ -1641,25 +1649,31 @@ class CI_Image_lib {
 		}
 
 		$vals = getimagesize($path);
+		if ($vals === FALSE)
+		{
+			$this->set_error('imglib_invalid_image');
+			return FALSE;
+		}
+
 		$types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');
-		$mime = (isset($types[$vals[2]])) ? 'image/'.$types[$vals[2]] : 'image/jpg';
+		$mime = isset($types[$vals[2]]) ? 'image/'.$types[$vals[2]] : 'image/jpg';
 
 		if ($return === TRUE)
 		{
 			return array(
-					'width' =>	$vals[0],
-					'height' =>	$vals[1],
-					'image_type' =>	$vals[2],
-					'size_str' =>	$vals[3],
-					'mime_type' =>	$mime
-				);
+				'width'      => $vals[0],
+				'height'     => $vals[1],
+				'image_type' => $vals[2],
+				'size_str'   => $vals[3],
+				'mime_type'  => $mime
+			);
 		}
 
-		$this->orig_width	= $vals[0];
-		$this->orig_height	= $vals[1];
-		$this->image_type	= $vals[2];
-		$this->size_str		= $vals[3];
-		$this->mime_type	= $mime;
+		$this->orig_width  = $vals[0];
+		$this->orig_height = $vals[1];
+		$this->image_type  = $vals[2];
+		$this->size_str    = $vals[3];
+		$this->mime_type   = $mime;
 
 		return TRUE;
 	}
diff --git a/src/system/libraries/Javascript.php b/src/system/libraries/Javascript.php
index dcf93377..7648526b 100644
--- a/src/system/libraries/Javascript.php
+++ b/src/system/libraries/Javascript.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/libraries/Migration.php b/src/system/libraries/Migration.php
index 316c94ae..2a87d9d7 100644
--- a/src/system/libraries/Migration.php
+++ b/src/system/libraries/Migration.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -288,10 +288,7 @@ class CI_Migration {
 				$this->_error_string = sprintf($this->lang->line('migration_class_doesnt_exist'), $class);
 				return FALSE;
 			}
-			// method_exists() returns true for non-public methods,
-			// while is_callable() can't be used without instantiating.
-			// Only get_class_methods() satisfies both conditions.
-			elseif ( ! in_array($method, array_map('strtolower', get_class_methods($class))))
+			elseif ( ! is_callable(array($class, $method)))
 			{
 				$this->_error_string = sprintf($this->lang->line('migration_missing_'.$method.'_method'), $class);
 				return FALSE;
diff --git a/src/system/libraries/Pagination.php b/src/system/libraries/Pagination.php
index 44f848fe..f26f8a4e 100644
--- a/src/system/libraries/Pagination.php
+++ b/src/system/libraries/Pagination.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -428,7 +428,7 @@ class CI_Pagination {
 		{
 			$get = $this->CI->input->get();
 
-			// Unset the controll, method, old-school routing options
+			// Unset the control, method, old-school routing options
 			unset($get['c'], $get['m'], $get[$this->query_string_segment]);
 		}
 		else
diff --git a/src/system/libraries/Parser.php b/src/system/libraries/Parser.php
index 22cffb2c..fdd958b2 100644
--- a/src/system/libraries/Parser.php
+++ b/src/system/libraries/Parser.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
diff --git a/src/system/libraries/Profiler.php b/src/system/libraries/Profiler.php
index cf455d3d..9ea09a52 100644
--- a/src/system/libraries/Profiler.php
+++ b/src/system/libraries/Profiler.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -316,7 +316,7 @@ class CI_Profiler {
 			{
 				is_int($key) OR $key = "'".htmlspecialchars($key, ENT_QUOTES, config_item('charset'))."'";
 				$val = (is_array($val) OR is_object($val))
-					? '<pre>'.htmlspecialchars(print_r($val, TRUE), ENT_QUOTES, config_item('charset'))
+					? '<pre>'.htmlspecialchars(print_r($val, TRUE), ENT_QUOTES, config_item('charset')).'</pre>'
 					: htmlspecialchars($val, ENT_QUOTES, config_item('charset'));
 
 				$output .= '<tr><td style="width:50%;color:#000;background-color:#ddd;padding:5px;">&#36;_GET['
@@ -356,7 +356,7 @@ class CI_Profiler {
 			{
 				is_int($key) OR $key = "'".htmlspecialchars($key, ENT_QUOTES, config_item('charset'))."'";
 				$val = (is_array($val) OR is_object($val))
-					? '<pre>'.htmlspecialchars(print_r($val, TRUE), ENT_QUOTES, config_item('charset'))
+					? '<pre>'.htmlspecialchars(print_r($val, TRUE), ENT_QUOTES, config_item('charset')).'</pre>'
 					: htmlspecialchars($val, ENT_QUOTES, config_item('charset'));
 
 				$output .= '<tr><td style="width:50%;padding:5px;color:#000;background-color:#ddd;">&#36;_POST['
@@ -368,7 +368,7 @@ class CI_Profiler {
 			{
 				is_int($key) OR $key = "'".htmlspecialchars($key, ENT_QUOTES, config_item('charset'))."'";
 				$val = (is_array($val) OR is_object($val))
-					? '<pre>'.htmlspecialchars(print_r($val, TRUE), ENT_QUOTES, config_item('charset'))
+					? '<pre>'.htmlspecialchars(print_r($val, TRUE), ENT_QUOTES, config_item('charset')).'</pre>'
 					: htmlspecialchars($val, ENT_QUOTES, config_item('charset'));
 
 				$output .= '<tr><td style="width:50%;padding:5px;color:#000;background-color:#ddd;">&#36;_FILES['
@@ -490,7 +490,7 @@ class CI_Profiler {
 			}
 
 			$output .= '<tr><td style="padding:5px;vertical-align:top;color:#900;background-color:#ddd;">'
-				.$config.'&nbsp;&nbsp;</td><td style="padding:5px;color:#000;background-color:#ddd;">'.htmlspecialchars($val)."</td></tr>\n";
+				.$config.'&nbsp;&nbsp;</td><td style="padding:5px;color:#000;background-color:#ddd;">'.htmlspecialchars($val, ENT_QUOTES, config_item('charset'))."</td></tr>\n";
 		}
 
 		return $output."</table>\n</fieldset>";
@@ -522,7 +522,7 @@ class CI_Profiler {
 			}
 
 			$output .= '<tr><td style="padding:5px;vertical-align:top;color:#900;background-color:#ddd;">'
-				.$key.'&nbsp;&nbsp;</td><td style="padding:5px;color:#000;background-color:#ddd;">'.htmlspecialchars($val)."</td></tr>\n";
+				.$key.'&nbsp;&nbsp;</td><td style="padding:5px;color:#000;background-color:#ddd;">'.htmlspecialchars($val, ENT_QUOTES, config_item('charset'))."</td></tr>\n";
 		}
 
 		return $output."</table>\n</fieldset>";
diff --git a/src/system/libraries/Session/Session.php b/src/system/libraries/Session/Session.php
index c9d2e8ad..eb433de6 100644
--- a/src/system/libraries/Session/Session.php
+++ b/src/system/libraries/Session/Session.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 2.0.0
@@ -57,6 +57,7 @@ class CI_Session {
 
 	protected $_driver = 'files';
 	protected $_config;
+	protected $_sid_regexp;
 
 	// ------------------------------------------------------------------------
 
@@ -91,6 +92,7 @@ class CI_Session {
 		// Note: BC workaround
 		elseif (config_item('sess_use_database'))
 		{
+			log_message('debug', 'Session: "sess_driver" is empty; using BC fallback to "sess_use_database".');
 			$this->_driver = 'database';
 		}
 
@@ -98,6 +100,7 @@ class CI_Session {
 
 		// Configuration ...
 		$this->_configure($params);
+		$this->_config['_sid_regexp'] = $this->_sid_regexp;
 
 		$class = new $class($this->_config);
 		if ($class instanceof SessionHandlerInterface)
@@ -130,7 +133,7 @@ class CI_Session {
 		if (isset($_COOKIE[$this->_config['cookie_name']])
 			&& (
 				! is_string($_COOKIE[$this->_config['cookie_name']])
-				OR ! preg_match('/^[0-9a-f]{40}$/', $_COOKIE[$this->_config['cookie_name']])
+				OR ! preg_match('#\A'.$this->_sid_regexp.'\z#', $_COOKIE[$this->_config['cookie_name']])
 			)
 		)
 		{
@@ -314,8 +317,82 @@ class CI_Session {
 		ini_set('session.use_strict_mode', 1);
 		ini_set('session.use_cookies', 1);
 		ini_set('session.use_only_cookies', 1);
-		ini_set('session.hash_function', 1);
-		ini_set('session.hash_bits_per_character', 4);
+
+		$this->_configure_sid_length();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Configure session ID length
+	 *
+	 * To make life easier, we used to force SHA-1 and 4 bits per
+	 * character on everyone. And of course, someone was unhappy.
+	 *
+	 * Then PHP 7.1 broke backwards-compatibility because ext/session
+	 * is such a mess that nobody wants to touch it with a pole stick,
+	 * and the one guy who does, nobody has the energy to argue with.
+	 *
+	 * So we were forced to make changes, and OF COURSE something was
+	 * going to break and now we have this pile of shit. -- Narf
+	 *
+	 * @return	void
+	 */
+	protected function _configure_sid_length()
+	{
+		if (PHP_VERSION_ID < 70100)
+		{
+			$hash_function = ini_get('session.hash_function');
+			if (ctype_digit($hash_function))
+			{
+				if ($hash_function !== '1')
+				{
+					ini_set('session.hash_function', 1);
+				}
+
+				$bits = 160;
+			}
+			elseif ( ! in_array($hash_function, hash_algos(), TRUE))
+			{
+				ini_set('session.hash_function', 1);
+				$bits = 160;
+			}
+			elseif (($bits = strlen(hash($hash_function, 'dummy', false)) * 4) < 160)
+			{
+				ini_set('session.hash_function', 1);
+				$bits = 160;
+			}
+
+			$bits_per_character = (int) ini_get('session.hash_bits_per_character');
+			$sid_length         = (int) ceil($bits / $bits_per_character);
+		}
+		else
+		{
+			$bits_per_character = (int) ini_get('session.sid_bits_per_character');
+			$sid_length         = (int) ini_get('session.sid_length');
+			if (($bits = $sid_length * $bits_per_character) < 160)
+			{
+				// Add as many more characters as necessary to reach at least 160 bits
+				$sid_length += (int) ceil((160 % $bits) / $bits_per_character);
+				ini_set('session.sid_length', $sid_length);
+			}
+		}
+
+		// Yes, 4,5,6 are the only known possible values as of 2016-10-27
+		switch ($bits_per_character)
+		{
+			case 4:
+				$this->_sid_regexp = '[0-9a-f]';
+				break;
+			case 5:
+				$this->_sid_regexp = '[0-9a-v]';
+				break;
+			case 6:
+				$this->_sid_regexp = '[0-9a-zA-Z,-]';
+				break;
+		}
+
+		$this->_sid_regexp .= '{'.$sid_length.'}';
 	}
 
 	// ------------------------------------------------------------------------
@@ -729,7 +806,7 @@ class CI_Session {
 	 *
 	 * Legacy CI_Session compatibility method
 	 *
-	 * @param	mixed	$data	Session data key(s)
+	 * @param	mixed	$key	Session data key(s)
 	 * @return	void
 	 */
 	public function unset_userdata($key)
diff --git a/src/system/libraries/Session/SessionHandlerInterface.php b/src/system/libraries/Session/SessionHandlerInterface.php
index b3533dd1..2eef61db 100644
--- a/src/system/libraries/Session/SessionHandlerInterface.php
+++ b/src/system/libraries/Session/SessionHandlerInterface.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/libraries/Session/Session_driver.php b/src/system/libraries/Session/Session_driver.php
index 55ddb25e..f32f14ae 100644
--- a/src/system/libraries/Session/Session_driver.php
+++ b/src/system/libraries/Session/Session_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
diff --git a/src/system/libraries/Session/drivers/Session_database_driver.php b/src/system/libraries/Session/drivers/Session_database_driver.php
index 317bd7d4..b519b782 100644
--- a/src/system/libraries/Session/drivers/Session_database_driver.php
+++ b/src/system/libraries/Session/drivers/Session_database_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -109,7 +109,10 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 		}
 
 		// Note: BC work-around for the old 'sess_table_name' setting, should be removed in the future.
-		isset($this->_config['save_path']) OR $this->_config['save_path'] = config_item('sess_table_name');
+		if ( ! isset($this->_config['save_path']) && ($this->_config['save_path'] = config_item('sess_table_name')))
+		{
+			log_message('debug', 'Session: "sess_save_path" is empty; using BC fallback to "sess_table_name".');
+		}
 	}
 
 	// ------------------------------------------------------------------------
@@ -206,7 +209,7 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 		$this->_db->reset_query();
 
 		// Was the ID regenerated?
-		if ($session_id !== $this->_session_id)
+		if (isset($this->_session_id) && $session_id !== $this->_session_id)
 		{
 			if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
 			{
@@ -351,7 +354,7 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	{
 		if ($this->_platform === 'mysql')
 		{
-			$arg = $session_id.($this->_config['match_ip'] ? '_'.$_SERVER['REMOTE_ADDR'] : '');
+			$arg = md5($session_id.($this->_config['match_ip'] ? '_'.$_SERVER['REMOTE_ADDR'] : ''));
 			if ($this->_db->query("SELECT GET_LOCK('".$arg."', 300) AS ci_session_lock")->row()->ci_session_lock)
 			{
 				$this->_lock = $arg;
@@ -414,4 +417,4 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 
 		return parent::_release_lock();
 	}
-}
\ No newline at end of file
+}
diff --git a/src/system/libraries/Session/drivers/Session_files_driver.php b/src/system/libraries/Session/drivers/Session_files_driver.php
index 119bf657..8860ef66 100644
--- a/src/system/libraries/Session/drivers/Session_files_driver.php
+++ b/src/system/libraries/Session/drivers/Session_files_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -76,6 +76,20 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 	 */
 	protected $_file_new;
 
+	/**
+	 * Validate SID regular expression
+	 *
+	 * @var	string
+	 */
+	protected $_sid_regexp;
+
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_overload;
+
 	// ------------------------------------------------------------------------
 
 	/**
@@ -95,8 +109,13 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 		}
 		else
 		{
+			log_message('debug', 'Session: "sess_save_path" is empty; using "session.save_path" value from php.ini.');
 			$this->_config['save_path'] = rtrim(ini_get('session.save_path'), '/\\');
 		}
+
+		$this->_sid_regexp = $this->_config['_sid_regexp'];
+
+		isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
 	}
 
 	// ------------------------------------------------------------------------
@@ -148,18 +167,9 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 		// which re-reads session data
 		if ($this->_file_handle === NULL)
 		{
-			// Just using fopen() with 'c+b' mode would be perfect, but it is only
-			// available since PHP 5.2.6 and we have to set permissions for new files,
-			// so we'd have to hack around this ...
-			if (($this->_file_new = ! file_exists($this->_file_path.$session_id)) === TRUE)
-			{
-				if (($this->_file_handle = fopen($this->_file_path.$session_id, 'w+b')) === FALSE)
-				{
-					log_message('error', "Session: File '".$this->_file_path.$session_id."' doesn't exist and cannot be created.");
-					return $this->_failure;
-				}
-			}
-			elseif (($this->_file_handle = fopen($this->_file_path.$session_id, 'r+b')) === FALSE)
+			$this->_file_new = ! file_exists($this->_file_path.$session_id);
+
+			if (($this->_file_handle = fopen($this->_file_path.$session_id, 'c+b')) === FALSE)
 			{
 				log_message('error', "Session: Unable to open file '".$this->_file_path.$session_id."'.");
 				return $this->_failure;
@@ -195,7 +205,7 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 		}
 
 		$session_data = '';
-		for ($read = 0, $length = filesize($this->_file_path.$session_id); $read < $length; $read += strlen($buffer))
+		for ($read = 0, $length = filesize($this->_file_path.$session_id); $read < $length; $read += self::strlen($buffer))
 		{
 			if (($buffer = fread($this->_file_handle, $length - $read)) === FALSE)
 			{
@@ -351,10 +361,13 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 
 		$ts = time() - $maxlifetime;
 
+		$pattern = ($this->_config['match_ip'] === TRUE)
+			? '[0-9a-f]{32}'
+			: '';
+
 		$pattern = sprintf(
-			'/^%s[0-9a-f]{%d}$/',
-			preg_quote($this->_config['cookie_name'], '/'),
-			($this->_config['match_ip'] === TRUE ? 72 : 40)
+			'#\A%s'.$pattern.$this->_sid_regexp.'\z#',
+			preg_quote($this->_config['cookie_name'])
 		);
 
 		while (($file = readdir($directory)) !== FALSE)
@@ -376,4 +389,18 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 		return $this->_success;
 	}
 
-}
\ No newline at end of file
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return (self::$func_overload)
+			? mb_strlen($str, '8bit')
+			: strlen($str);
+	}
+}
diff --git a/src/system/libraries/Session/drivers/Session_memcached_driver.php b/src/system/libraries/Session/drivers/Session_memcached_driver.php
index 88eb4b3a..2556bf0f 100644
--- a/src/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/src/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -186,7 +186,7 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 	 */
 	public function write($session_id, $session_data)
 	{
-		if ( ! isset($this->_memcached))
+		if ( ! isset($this->_memcached, $this->_lock_key))
 		{
 			return $this->_fail();
 		}
@@ -202,32 +202,25 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 			$this->_session_id = $session_id;
 		}
 
-		if (isset($this->_lock_key))
+		$key = $this->_key_prefix.$session_id;
+
+		$this->_memcached->replace($this->_lock_key, time(), 300);
+		if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
 		{
-			$key = $this->_key_prefix.$session_id;
-
-			$this->_memcached->replace($this->_lock_key, time(), 300);
-			if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
-			{
-				if (
-					$this->_memcached->replace($key, $session_data, $this->_config['expiration'])
-					OR ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND && $this->_memcached->set($key, $session_data, $this->_config['expiration']))
-				)
-				{
-					$this->_fingerprint = $fingerprint;
-					return $this->_success;
-				}
-
-				return $this->_fail();
-			}
-
-			if (
-				$this->_memcached->touch($key, $this->_config['expiration'])
-				OR ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND && $this->_memcached->set($key, $session_data, $this->_config['expiration']))
-			)
+			if ($this->_memcached->set($key, $session_data, $this->_config['expiration']))
 			{
+				$this->_fingerprint = $fingerprint;
 				return $this->_success;
 			}
+
+			return $this->_fail();
+		}
+		elseif (
+			$this->_memcached->touch($key, $this->_config['expiration'])
+			OR ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND && $this->_memcached->set($key, $session_data, $this->_config['expiration']))
+		)
+		{
+			return $this->_success;
 		}
 
 		return $this->_fail();
@@ -379,4 +372,4 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 
 		return TRUE;
 	}
-}
\ No newline at end of file
+}
diff --git a/src/system/libraries/Session/drivers/Session_redis_driver.php b/src/system/libraries/Session/drivers/Session_redis_driver.php
index e4e09fe0..d260f7b8 100644
--- a/src/system/libraries/Session/drivers/Session_redis_driver.php
+++ b/src/system/libraries/Session/drivers/Session_redis_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 3.0.0
@@ -199,7 +199,7 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 	 */
 	public function write($session_id, $session_data)
 	{
-		if ( ! isset($this->_redis))
+		if ( ! isset($this->_redis, $this->_lock_key))
 		{
 			return $this->_fail();
 		}
@@ -215,27 +215,22 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 			$this->_session_id = $session_id;
 		}
 
-		if (isset($this->_lock_key))
+		$this->_redis->setTimeout($this->_lock_key, 300);
+		if ($this->_fingerprint !== ($fingerprint = md5($session_data)) OR $this->_key_exists === FALSE)
 		{
-			$this->_redis->setTimeout($this->_lock_key, 300);
-			if ($this->_fingerprint !== ($fingerprint = md5($session_data)) OR $this->_key_exists === FALSE)
+			if ($this->_redis->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration']))
 			{
-				if ($this->_redis->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration']))
-				{
-					$this->_fingerprint = $fingerprint;
-					$this->_key_exists = TRUE;
-					return $this->_success;
-				}
-
-				return $this->_fail();
+				$this->_fingerprint = $fingerprint;
+				$this->_key_exists = TRUE;
+				return $this->_success;
 			}
 
-			return ($this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_config['expiration']))
-				? $this->_success
-				: $this->_fail();
+			return $this->_fail();
 		}
 
-		return $this->_fail();
+		return ($this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_config['expiration']))
+			? $this->_success
+			: $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -255,7 +250,7 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 				if ($this->_redis->ping() === '+PONG')
 				{
 					$this->_release_lock();
-					if ($this->_redis->close() === $this->_failure)
+					if ($this->_redis->close() === FALSE)
 					{
 						return $this->_fail();
 					}
diff --git a/src/system/libraries/Table.php b/src/system/libraries/Table.php
index 3bce294d..fef9bb03 100644
--- a/src/system/libraries/Table.php
+++ b/src/system/libraries/Table.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.1
@@ -277,6 +277,7 @@ class CI_Table {
 	public function set_caption($caption)
 	{
 		$this->caption = $caption;
+		return $this;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/src/system/libraries/Trackback.php b/src/system/libraries/Trackback.php
index a9b25646..55e9a0ee 100644
--- a/src/system/libraries/Trackback.php
+++ b/src/system/libraries/Trackback.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -370,7 +370,7 @@ class CI_Trackback {
 	{
 		$url = trim($url);
 
-		if (strpos($url, 'http') !== 0)
+		if (stripos($url, 'http') !== 0)
 		{
 			$url = 'http://'.$url;
 		}
diff --git a/src/system/libraries/Typography.php b/src/system/libraries/Typography.php
index c45398bd..b25d8fda 100644
--- a/src/system/libraries/Typography.php
+++ b/src/system/libraries/Typography.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -241,7 +241,7 @@ class CI_Typography {
 						// Clean up stray paragraph tags that appear before block level elements
 						'#<p></p><('.$this->block_elements.')#'	=> '<$1',
 
-						// Clean up stray non-breaking spaces preceeding block elements
+						// Clean up stray non-breaking spaces preceding block elements
 						'#(&nbsp;\s*)+<('.$this->block_elements.')#'	=> '  <$2',
 
 						// Replace the temporary markers we added earlier
diff --git a/src/system/libraries/Unit_test.php b/src/system/libraries/Unit_test.php
index 3ac6af78..38e0fbd2 100644
--- a/src/system/libraries/Unit_test.php
+++ b/src/system/libraries/Unit_test.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.3.1
@@ -154,7 +154,6 @@ class CI_Unit_test {
 
 		if (in_array($expected, array('is_object', 'is_string', 'is_bool', 'is_true', 'is_false', 'is_int', 'is_numeric', 'is_float', 'is_double', 'is_array', 'is_null', 'is_resource'), TRUE))
 		{
-			$expected = str_replace('is_double', 'is_float', $expected);
 			$result = $expected($test);
 			$extype = str_replace(array('true', 'false'), 'bool', str_replace('is_', '', $expected));
 		}
@@ -291,7 +290,7 @@ class CI_Unit_test {
 				{
 					continue;
 				}
-				elseif (in_array($key, array('test_name', 'test_datatype', 'test_res_datatype', 'result'), TRUE))
+				elseif (in_array($key, array('test_name', 'test_datatype', 'res_datatype', 'result'), TRUE))
 				{
 					if (FALSE !== ($line = $CI->lang->line(strtolower('ut_'.$val), FALSE)))
 					{
diff --git a/src/system/libraries/Upload.php b/src/system/libraries/Upload.php
index f2418378..b37cc2f5 100644
--- a/src/system/libraries/Upload.php
+++ b/src/system/libraries/Upload.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -286,7 +286,7 @@ class CI_Upload {
 	/**
 	 * Constructor
 	 *
-	 * @param	array	$props
+	 * @param	array	$config
 	 * @return	void
 	 */
 	public function __construct($config = array())
@@ -601,7 +601,7 @@ class CI_Upload {
 				'file_type'		=> $this->file_type,
 				'file_path'		=> $this->upload_path,
 				'full_path'		=> $this->upload_path.$this->file_name,
-				'raw_name'		=> str_replace($this->file_ext, '', $this->file_name),
+				'raw_name'		=> substr($this->file_name, 0, -strlen($this->file_ext)),
 				'orig_name'		=> $this->orig_name,
 				'client_name'		=> $this->client_name,
 				'file_ext'		=> $this->file_ext,
@@ -1083,16 +1083,27 @@ class CI_Upload {
 			return FALSE;
 		}
 
-		if (memory_get_usage() && ($memory_limit = ini_get('memory_limit')))
+		if (memory_get_usage() && ($memory_limit = ini_get('memory_limit')) > 0)
 		{
-			$memory_limit *= 1024 * 1024;
-
-			// There was a bug/behavioural change in PHP 5.2, where numbers over one million get output
-			// into scientific notation. number_format() ensures this number is an integer
-			// http://bugs.php.net/bug.php?id=43053
-
-			$memory_limit = number_format(ceil(filesize($file) + $memory_limit), 0, '.', '');
+			$memory_limit = str_split($memory_limit, strspn($memory_limit, '1234567890'));
+			if ( ! empty($memory_limit[1]))
+			{
+				switch ($memory_limit[1][0])
+				{
+					case 'g':
+					case 'G':
+						$memory_limit[0] *= 1024 * 1024 * 1024;
+						break;
+					case 'm':
+					case 'M':
+						$memory_limit[0] *= 1024 * 1024;
+						break;
+					default:
+						break;
+				}
+			}
 
+			$memory_limit = (int) ceil(filesize($file) + $memory_limit[0]);
 			ini_set('memory_limit', $memory_limit); // When an integer is used, the value is measured in bytes. - PHP.net
 		}
 
@@ -1207,10 +1218,13 @@ class CI_Upload {
 		// We'll need this to validate the MIME info string (e.g. text/plain; charset=us-ascii)
 		$regexp = '/^([a-z\-]+\/[a-z0-9\-\.\+]+)(;\s.+)?$/';
 
-		/* Fileinfo extension - most reliable method
+		/**
+		 * Fileinfo extension - most reliable method
 		 *
-		 * Unfortunately, prior to PHP 5.3 - it's only available as a PECL extension and the
-		 * more convenient FILEINFO_MIME_TYPE flag doesn't exist.
+		 * Apparently XAMPP, CentOS, cPanel and who knows what
+		 * other PHP distribution channels EXPLICITLY DISABLE
+		 * ext/fileinfo, which is otherwise enabled by default
+		 * since PHP 5.3 ...
 		 */
 		if (function_exists('finfo_file'))
 		{
diff --git a/src/system/libraries/User_agent.php b/src/system/libraries/User_agent.php
index c4e11592..cda3ef0a 100644
--- a/src/system/libraries/User_agent.php
+++ b/src/system/libraries/User_agent.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -173,13 +173,11 @@ class CI_User_agent {
 	 */
 	public function __construct()
 	{
+		$this->_load_agent_file();
+
 		if (isset($_SERVER['HTTP_USER_AGENT']))
 		{
 			$this->agent = trim($_SERVER['HTTP_USER_AGENT']);
-		}
-
-		if ($this->agent !== NULL && $this->_load_agent_file())
-		{
 			$this->_compile_data();
 		}
 
diff --git a/src/system/libraries/Xmlrpc.php b/src/system/libraries/Xmlrpc.php
index f965858e..c766a89c 100644
--- a/src/system/libraries/Xmlrpc.php
+++ b/src/system/libraries/Xmlrpc.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -238,7 +238,7 @@ class CI_Xmlrpc {
 	public $result;
 
 	/**
-	 * XML-RPC Reponse
+	 * XML-RPC Response
 	 *
 	 * @var	array
 	 */
@@ -352,7 +352,7 @@ class CI_Xmlrpc {
 	 */
 	public function server($url, $port = 80, $proxy = FALSE, $proxy_port = 8080)
 	{
-		if (strpos($url, 'http') !== 0)
+		if (stripos($url, 'http') !== 0)
 		{
 			$url = 'http://'.$url;
 		}
@@ -460,7 +460,7 @@ class CI_Xmlrpc {
 			{
 				if (is_array($value[0]) && ($value[1] === 'struct' OR $value[1] === 'array'))
 				{
-					while (list($k) = each($value[0]))
+					foreach (array_keys($value[0]) as $k)
 					{
 						$value[0][$k] = $this->values_parsing($value[0][$k]);
 					}
@@ -735,6 +735,8 @@ class XML_RPC_Client extends CI_Xmlrpc
 			.'Content-Length: '.strlen($msg->payload).$r.$r
 			.$msg->payload;
 
+		stream_set_timeout($fp, $this->timeout); // set timeout for subsequent operations
+
 		for ($written = $timestamp = 0, $length = strlen($op); $written < $length; $written += $result)
 		{
 			if (($result = fwrite($fp, substr($op, $written))) === FALSE)
@@ -753,9 +755,6 @@ class XML_RPC_Client extends CI_Xmlrpc
 					$result = FALSE;
 					break;
 				}
-
-				usleep(250000);
-				continue;
 			}
 			else
 			{
@@ -932,15 +931,15 @@ class XML_RPC_Response
 
 		if (is_array($array))
 		{
-			while (list($key) = each($array))
+			foreach ($array as $key => &$value)
 			{
-				if (is_array($array[$key]))
+				if (is_array($value))
 				{
-					$array[$key] = $this->decode($array[$key]);
+					$array[$key] = $this->decode($value);
 				}
 				elseif ($this->xss_clean)
 				{
-					$array[$key] = $CI->security->xss_clean($array[$key]);
+					$array[$key] = $CI->security->xss_clean($value);
 				}
 			}
 
@@ -994,10 +993,11 @@ class XML_RPC_Response
 			reset($xmlrpc_val->me['struct']);
 			$arr = array();
 
-			while (list($key,$value) = each($xmlrpc_val->me['struct']))
+			foreach ($xmlrpc_val->me['struct'] as $key => &$value)
 			{
 				$arr[$key] = $this->xmlrpc_decoder($value);
 			}
+
 			return $arr;
 		}
 	}
@@ -1563,17 +1563,17 @@ class XML_RPC_Message extends CI_Xmlrpc
 
 		if ( ! empty($array))
 		{
-			while (list($key) = each($array))
+			foreach ($array as $key => &$value)
 			{
-				if (is_array($array[$key]))
+				if (is_array($value))
 				{
-					$array[$key] = $this->output_parameters($array[$key]);
+					$array[$key] = $this->output_parameters($value);
 				}
 				elseif ($key !== 'bits' && $this->xss_clean)
 				{
 					// 'bits' is for the MetaWeblog API image bits
 					// @todo - this needs to be made more general purpose
-					$array[$key] = $CI->security->xss_clean($array[$key]);
+					$array[$key] = $CI->security->xss_clean($value);
 				}
 			}
 
@@ -1633,7 +1633,7 @@ class XML_RPC_Message extends CI_Xmlrpc
 			reset($param->me['struct']);
 			$arr = array();
 
-			while (list($key,$value) = each($param->me['struct']))
+			foreach ($param->me['struct'] as $key => &$value)
 			{
 				$arr[$key] = $this->decode_message($value);
 			}
@@ -1824,7 +1824,7 @@ class XML_RPC_Values extends CI_Xmlrpc
 				// struct
 				$rs .= "<struct>\n";
 				reset($val);
-				while (list($key2, $val2) = each($val))
+				foreach ($val as $key2 => &$val2)
 				{
 					$rs .= "<member>\n<name>{$key2}</name>\n".$this->serializeval($val2)."</member>\n";
 				}
@@ -1885,11 +1885,9 @@ class XML_RPC_Values extends CI_Xmlrpc
 	 */
 	public function serializeval($o)
 	{
-		$ar = $o->me;
-		reset($ar);
-
-		list($typ, $val) = each($ar);
-		return "<value>\n".$this->serializedata($typ, $val)."</value>\n";
+		$array = $o->me;
+		list($value, $type) = array(reset($ar), key($array));
+		return "<value>\n".$this->serializedata($type, $value)."</value>\n";
 	}
 
 	// --------------------------------------------------------------------
@@ -1901,8 +1899,7 @@ class XML_RPC_Values extends CI_Xmlrpc
 	 */
 	public function scalarval()
 	{
-		reset($this->me);
-		return current($this->me);
+		return reset($this->me);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/src/system/libraries/Xmlrpcs.php b/src/system/libraries/Xmlrpcs.php
index afcdbe68..0274f13b 100644
--- a/src/system/libraries/Xmlrpcs.php
+++ b/src/system/libraries/Xmlrpcs.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -339,11 +339,11 @@ class CI_Xmlrpcs extends CI_Xmlrpc {
 		//-------------------------------------
 
 		$method_parts = explode('.', $this->methods[$methName]['function']);
-		$objectCall = (isset($method_parts[1]) && $method_parts[1] !== '');
+		$objectCall   = ! empty($method_parts[1]);
 
 		if ($system_call === TRUE)
 		{
-			if ( ! is_callable(array($this,$method_parts[1])))
+			if ( ! is_callable(array($this, $method_parts[1])))
 			{
 				return new XML_RPC_Response(0, $this->xmlrpcerr['unknown_method'], $this->xmlrpcstr['unknown_method']);
 			}
@@ -400,11 +400,11 @@ class CI_Xmlrpcs extends CI_Xmlrpc {
 			}
 			elseif ($this->object === FALSE)
 			{
-				return get_instance()->$method_parts[1]($m);
+				return get_instance()->{$method_parts[1]}($m);
 			}
 			else
 			{
-				return $this->object->$method_parts[1]($m);
+				return $this->object->{$method_parts[1]}($m);
 			}
 		}
 		else
@@ -584,7 +584,7 @@ class CI_Xmlrpcs extends CI_Xmlrpc {
 			return $this->multicall_error('nomethod');
 		}
 
-		list($scalar_type, $scalar_value) = each($methName->me);
+		list($scalar_value, $scalar_type) = array(reset($methName->me), key($methName->me));
 		$scalar_type = $scalar_type === $this->xmlrpcI4 ? $this->xmlrpcInt : $scalar_type;
 
 		if ($methName->kindOf() !== 'scalar' OR $scalar_type !== 'string')
@@ -604,7 +604,7 @@ class CI_Xmlrpcs extends CI_Xmlrpc {
 			return $this->multicall_error('notarray');
 		}
 
-		list($a, $b) = each($params->me);
+		list($b, $a) = array(reset($params->me), key($params->me));
 
 		$msg = new XML_RPC_Message($scalar_value);
 		for ($i = 0, $numParams = count($b); $i < $numParams; $i++)
diff --git a/src/system/libraries/Zip.php b/src/system/libraries/Zip.php
index 140ad721..2c71e1fb 100644
--- a/src/system/libraries/Zip.php
+++ b/src/system/libraries/Zip.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -105,6 +105,13 @@ class CI_Zip {
 	 */
 	public $compression_level = 2;
 
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_overload;
+
 	/**
 	 * Initialize zip compression class
 	 *
@@ -112,6 +119,8 @@ class CI_Zip {
 	 */
 	public function __construct()
 	{
+		isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
+
 		$this->now = time();
 		log_message('info', 'Zip Compression Class Initialized');
 	}
@@ -182,7 +191,7 @@ class CI_Zip {
 			.pack('V', 0) // crc32
 			.pack('V', 0) // compressed filesize
 			.pack('V', 0) // uncompressed filesize
-			.pack('v', strlen($dir)) // length of pathname
+			.pack('v', self::strlen($dir)) // length of pathname
 			.pack('v', 0) // extra field length
 			.$dir
 			// below is "data descriptor" segment
@@ -197,7 +206,7 @@ class CI_Zip {
 			.pack('V',0) // crc32
 			.pack('V',0) // compressed filesize
 			.pack('V',0) // uncompressed filesize
-			.pack('v', strlen($dir)) // length of pathname
+			.pack('v', self::strlen($dir)) // length of pathname
 			.pack('v', 0) // extra field length
 			.pack('v', 0) // file comment length
 			.pack('v', 0) // disk number start
@@ -206,7 +215,7 @@ class CI_Zip {
 			.pack('V', $this->offset) // relative offset of local header
 			.$dir;
 
-		$this->offset = strlen($this->zipdata);
+		$this->offset = self::strlen($this->zipdata);
 		$this->entries++;
 	}
 
@@ -255,10 +264,10 @@ class CI_Zip {
 	{
 		$filepath = str_replace('\\', '/', $filepath);
 
-		$uncompressed_size = strlen($data);
+		$uncompressed_size = self::strlen($data);
 		$crc32  = crc32($data);
-		$gzdata = substr(gzcompress($data, $this->compression_level), 2, -4);
-		$compressed_size = strlen($gzdata);
+		$gzdata = self::substr(gzcompress($data, $this->compression_level), 2, -4);
+		$compressed_size = self::strlen($gzdata);
 
 		$this->zipdata .=
 			"\x50\x4b\x03\x04\x14\x00\x00\x00\x08\x00"
@@ -267,7 +276,7 @@ class CI_Zip {
 			.pack('V', $crc32)
 			.pack('V', $compressed_size)
 			.pack('V', $uncompressed_size)
-			.pack('v', strlen($filepath)) // length of filename
+			.pack('v', self::strlen($filepath)) // length of filename
 			.pack('v', 0) // extra field length
 			.$filepath
 			.$gzdata; // "file data" segment
@@ -279,7 +288,7 @@ class CI_Zip {
 			.pack('V', $crc32)
 			.pack('V', $compressed_size)
 			.pack('V', $uncompressed_size)
-			.pack('v', strlen($filepath)) // length of filename
+			.pack('v', self::strlen($filepath)) // length of filename
 			.pack('v', 0) // extra field length
 			.pack('v', 0) // file comment length
 			.pack('v', 0) // disk number start
@@ -288,7 +297,7 @@ class CI_Zip {
 			.pack('V', $this->offset) // relative offset of local header
 			.$filepath;
 
-		$this->offset = strlen($this->zipdata);
+		$this->offset = self::strlen($this->zipdata);
 		$this->entries++;
 		$this->file_num++;
 	}
@@ -401,8 +410,8 @@ class CI_Zip {
 			.$this->directory."\x50\x4b\x05\x06\x00\x00\x00\x00"
 			.pack('v', $this->entries) // total # of entries "on this disk"
 			.pack('v', $this->entries) // total # of entries overall
-			.pack('V', strlen($this->directory)) // size of central dir
-			.pack('V', strlen($this->zipdata)) // offset to start of central dir
+			.pack('V', self::strlen($this->directory)) // size of central dir
+			.pack('V', self::strlen($this->zipdata)) // offset to start of central dir
 			."\x00\x00"; // .zip file comment length
 	}
 
@@ -425,9 +434,9 @@ class CI_Zip {
 
 		flock($fp, LOCK_EX);
 
-		for ($result = $written = 0, $data = $this->get_zip(), $length = strlen($data); $written < $length; $written += $result)
+		for ($result = $written = 0, $data = $this->get_zip(), $length = self::strlen($data); $written < $length; $written += $result)
 		{
-			if (($result = fwrite($fp, substr($data, $written))) === FALSE)
+			if (($result = fwrite($fp, self::substr($data, $written))) === FALSE)
 			{
 				break;
 			}
@@ -481,4 +490,43 @@ class CI_Zip {
 		return $this;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return (self::$func_overload)
+			? mb_strlen($str, '8bit')
+			: strlen($str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param	string	$str
+	 * @param	int	$start
+	 * @param	int	$length
+	 * @return	string
+	 */
+	protected static function substr($str, $start, $length = NULL)
+	{
+		if (self::$func_overload)
+		{
+			// mb_substr($str, $start, null, '8bit') returns an empty
+			// string on PHP 5.3
+			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length)
+			? substr($str, $start, $length)
+			: substr($str, $start);
+	}
 }
diff --git a/src/system/libraries/javascript/Jquery.php b/src/system/libraries/javascript/Jquery.php
index 9df1be1c..ee5f9dea 100644
--- a/src/system/libraries/javascript/Jquery.php
+++ b/src/system/libraries/javascript/Jquery.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0