Merge branch 'develop' of git://github.com/bcit-ci/CodeIgniter into develop

39 files changed, 1536 insertions, 3579 deletions

diff --git a/system/libraries/Cache/Cache.php b/system/libraries/Cache/Cache.php
index 0c87a5628..267dffb09 100644
--- a/system/libraries/Cache/Cache.php
+++ b/system/libraries/Cache/Cache.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0.0
  * @filesource
  */
diff --git a/system/libraries/Cache/drivers/Cache_apc.php b/system/libraries/Cache/drivers/Cache_apc.php
index e0d2ffb39..f2b61adb1 100644
--- a/system/libraries/Cache/drivers/Cache_apc.php
+++ b/system/libraries/Cache/drivers/Cache_apc.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0.0
  * @filesource
  */
@@ -49,6 +49,24 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 class CI_Cache_apc extends CI_Driver {
 
 	/**
+	 * Class constructor
+	 *
+	 * Only present so that an error message is logged
+	 * if APC is not available.
+	 *
+	 * @return	void
+	 */
+	public function __construct()
+	{
+		if ( ! $this->is_supported())
+		{
+			log_message('error', 'Cache: Failed to initialize APC; extension not loaded/enabled?');
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
 	 * Get
 	 *
 	 * Look for a value in the cache. If it exists, return the data
@@ -79,7 +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
 	 */
@@ -198,13 +216,6 @@ class CI_Cache_apc extends CI_Driver {
 	 */
 	public function is_supported()
 	{
-		if ( ! extension_loaded('apc') OR ! ini_get('apc.enabled'))
-		{
-			log_message('debug', 'The APC PHP extension must be loaded to use APC Cache.');
-			return FALSE;
-		}
-
-		return TRUE;
+		return (extension_loaded('apc') && ini_get('apc.enabled'));
 	}
-
 }
diff --git a/system/libraries/Cache/drivers/Cache_dummy.php b/system/libraries/Cache/drivers/Cache_dummy.php
index bf80945a9..c6d9a61f1 100644
--- a/system/libraries/Cache/drivers/Cache_dummy.php
+++ b/system/libraries/Cache/drivers/Cache_dummy.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0
  * @filesource
  */
diff --git a/system/libraries/Cache/drivers/Cache_file.php b/system/libraries/Cache/drivers/Cache_file.php
index 68bc1ec96..8a36e9d79 100644
--- a/system/libraries/Cache/drivers/Cache_file.php
+++ b/system/libraries/Cache/drivers/Cache_file.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0
  * @filesource
  */
@@ -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'	 => $mtime
 			);
 		}
@@ -267,7 +267,7 @@ class CI_Cache_file extends CI_Driver {
 	 */
 	protected function _get($id)
 	{
-		if ( ! file_exists($this->_cache_path.$id))
+		if ( ! is_file($this->_cache_path.$id))
 		{
 			return FALSE;
 		}
diff --git a/system/libraries/Cache/drivers/Cache_memcached.php b/system/libraries/Cache/drivers/Cache_memcached.php
index 111e2109d..4836b6aed 100644
--- a/system/libraries/Cache/drivers/Cache_memcached.php
+++ b/system/libraries/Cache/drivers/Cache_memcached.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0
  * @filesource
  */
@@ -60,7 +60,7 @@ class CI_Cache_memcached extends CI_Driver {
 	 *
 	 * @var array
 	 */
-	protected $_memcache_conf = array(
+	protected $_config = array(
 		'default' => array(
 			'host'		=> '127.0.0.1',
 			'port'		=> 11211,
@@ -81,19 +81,11 @@ class CI_Cache_memcached extends CI_Driver {
 	{
 		// Try to load memcached server info from the config file.
 		$CI =& get_instance();
-		$defaults = $this->_memcache_conf['default'];
+		$defaults = $this->_config['default'];
 
 		if ($CI->config->load('memcached', TRUE, TRUE))
 		{
-			if (is_array($CI->config->config['memcached']))
-			{
-				$this->_memcache_conf = array();
-
-				foreach ($CI->config->config['memcached'] as $name => $conf)
-				{
-					$this->_memcache_conf[$name] = $conf;
-				}
-			}
+			$this->_config = $CI->config->config['memcached'];
 		}
 
 		if (class_exists('Memcached', FALSE))
@@ -106,18 +98,31 @@ class CI_Cache_memcached extends CI_Driver {
 		}
 		else
 		{
-			throw new RuntimeException('Cache: Failed to create Memcache(d) object; extension not loaded?');
+			log_message('error', 'Cache: Failed to create Memcache(d) object; extension not loaded?');
+			return;
 		}
 
-		foreach ($this->_memcache_conf as $cache_server)
+		foreach ($this->_config as $cache_name => $cache_server)
 		{
-			isset($cache_server['hostname']) OR $cache_server['hostname'] = $defaults['host'];
-			isset($cache_server['port']) OR $cache_server['port'] = $defaults['port'];
+			if ( ! isset($cache_server['hostname']))
+			{
+				log_message('debug', 'Cache: Memcache(d) configuration "'.$cache_name.'" doesn\'t include a hostname; ignoring.');
+				continue;
+			}
+			elseif ($cache_server['hostname'][0] === '/')
+			{
+				$cache_server['port'] = 0;
+			}
+			elseif (empty($cache_server['port']))
+			{
+				$cache_server['port'] = $defaults['port'];
+			}
+
 			isset($cache_server['weight']) OR $cache_server['weight'] = $defaults['weight'];
 
-			if (get_class($this->_memcached) === 'Memcache')
+			if ($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'],
@@ -125,7 +130,7 @@ class CI_Cache_memcached extends CI_Driver {
 					$cache_server['weight']
 				);
 			}
-			else
+			elseif ($this->_memcached instanceof Memcached)
 			{
 				$this->_memcached->addServer(
 					$cache_server['hostname'],
@@ -169,11 +174,11 @@ class CI_Cache_memcached extends CI_Driver {
 			$data = array($data, time(), $ttl);
 		}
 
-		if (get_class($this->_memcached) === 'Memcached')
+		if ($this->_memcached instanceof Memcached)
 		{
 			return $this->_memcached->set($id, $data, $ttl);
 		}
-		elseif (get_class($this->_memcached) === 'Memcache')
+		elseif ($this->_memcached instanceof Memcache)
 		{
 			return $this->_memcached->set($id, $data, 0, $ttl);
 		}
@@ -186,7 +191,7 @@ class CI_Cache_memcached extends CI_Driver {
 	/**
 	 * Delete from Cache
 	 *
-	 * @param	mixed	key to be deleted.
+	 * @param	mixed	$id	key to be deleted.
 	 * @return	bool	true on success, false on failure
 	 */
 	public function delete($id)
@@ -251,7 +256,7 @@ class CI_Cache_memcached extends CI_Driver {
 	/**
 	 * Get Cache Metadata
 	 *
-	 * @param	mixed	key to get cache metadata on
+	 * @param	mixed	$id	key to get cache metadata on
 	 * @return	mixed	FALSE on failure, array on success.
 	 */
 	public function get_metadata($id)
@@ -284,12 +289,27 @@ class CI_Cache_memcached extends CI_Driver {
 	 */
 	public function is_supported()
 	{
-		if ( ! extension_loaded('memcached') && ! extension_loaded('memcache'))
+		return (extension_loaded('memcached') OR extension_loaded('memcache'));
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Class destructor
+	 *
+	 * Closes the connection to Memcache(d) if present.
+	 *
+	 * @return	void
+	 */
+	public function __destruct()
+	{
+		if ($this->_memcached instanceof Memcache)
 		{
-			log_message('debug', 'The Memcached Extension must be loaded to use Memcached Cache.');
-			return FALSE;
+			$this->_memcached->close();
+		}
+		elseif ($this->_memcached instanceof Memcached && method_exists($this->_memcached, 'quit'))
+		{
+			$this->_memcached->quit();
 		}
-
-		return TRUE;
 	}
 }
diff --git a/system/libraries/Cache/drivers/Cache_redis.php b/system/libraries/Cache/drivers/Cache_redis.php
index d7dca1973..bb26b3b47 100644
--- a/system/libraries/Cache/drivers/Cache_redis.php
+++ b/system/libraries/Cache/drivers/Cache_redis.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -55,11 +55,11 @@ class CI_Cache_redis extends CI_Driver
 	 * @var	array
 	 */
 	protected static $_default_config = array(
-		'socket_type' => 'tcp',
 		'host' => '127.0.0.1',
 		'password' => NULL,
 		'port' => 6379,
-		'timeout' => 0
+		'timeout' => 0,
+		'database' => 0
 	);
 
 	/**
@@ -69,13 +69,6 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	protected $_redis;
 
-	/**
-	 * An internal cache for storing keys of serialized values.
-	 *
-	 * @var	array
-	 */
-	protected $_serialized = array();
-
 	// ------------------------------------------------------------------------
 
 	/**
@@ -91,46 +84,46 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	public function __construct()
 	{
-		$config = array();
+		if ( ! $this->is_supported())
+		{
+			log_message('error', 'Cache: Failed to create Redis object; extension not loaded?');
+			return;
+		}
+
 		$CI =& get_instance();
 
 		if ($CI->config->load('redis', TRUE, TRUE))
 		{
-			$config = $CI->config->item('redis');
+			$config = array_merge(self::$_default_config, $CI->config->item('redis'));
+		}
+		else
+		{
+			$config = self::$_default_config;
 		}
 
-		$config = array_merge(self::$_default_config, $config);
 		$this->_redis = new Redis();
 
 		try
 		{
-			if ($config['socket_type'] === 'unix')
+			if ( ! $this->_redis->connect($config['host'], ($config['host'][0] === '/' ? 0 : $config['port']), $config['timeout']))
 			{
-				$success = $this->_redis->connect($config['socket']);
+				log_message('error', 'Cache: Redis connection failed. Check your configuration.');
 			}
-			else // tcp socket
+
+			if (isset($config['password']) && ! $this->_redis->auth($config['password']))
 			{
-				$success = $this->_redis->connect($config['host'], $config['port'], $config['timeout']);
+				log_message('error', 'Cache: Redis authentication failed.');
 			}
 
-			if ( ! $success)
+			if (isset($config['database']) && $config['database'] > 0 && ! $this->_redis->select($config['database']))
 			{
-				throw new RuntimeException('Cache: Redis connection failed. Check your configuration.');
+				log_message('error', 'Cache: Redis select database failed.');
 			}
 		}
 		catch (RedisException $e)
 		{
-			throw new RuntimeException('Cache: Redis connection refused ('.$e->getMessage().')');
+			log_message('error', 'Cache: Redis connection refused ('.$e->getMessage().')');
 		}
-
-		if (isset($config['password']) && ! $this->_redis->auth($config['password']))
-		{
-			throw new RuntimeException('Cache: Redis authentication failed.');
-		}
-
-		// Initialize the index of serialized values.
-		$serialized = $this->_redis->sMembers('_ci_redis_serialized');
-		empty($serialized) OR $this->_serialized = array_flip($serialized);
 	}
 
 	// ------------------------------------------------------------------------
@@ -138,19 +131,35 @@ class CI_Cache_redis extends CI_Driver
 	/**
 	 * Get cache
 	 *
-	 * @param	string	Cache ID
+	 * @param	string	$key	Cache ID
 	 * @return	mixed
 	 */
 	public function get($key)
 	{
-		$value = $this->_redis->get($key);
+		$data = $this->_redis->hMGet($key, array('__ci_type', '__ci_value'));
 
-		if ($value !== FALSE && isset($this->_serialized[$key]))
+		if ( ! isset($data['__ci_type'], $data['__ci_value']) OR $data['__ci_value'] === FALSE)
 		{
-			return unserialize($value);
+			return FALSE;
 		}
 
-		return $value;
+		switch ($data['__ci_type'])
+		{
+			case 'array':
+			case 'object':
+				return unserialize($data['__ci_value']);
+			case 'boolean':
+			case 'integer':
+			case 'double': // Yes, 'double' is returned and NOT 'float'
+			case 'string':
+			case 'NULL':
+				return settype($data['__ci_value'], $data['__ci_type'])
+					? $data['__ci_value']
+					: FALSE;
+			case 'resource':
+			default:
+				return FALSE;
+		}
 	}
 
 	// ------------------------------------------------------------------------
@@ -166,23 +175,33 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	public function save($id, $data, $ttl = 60, $raw = FALSE)
 	{
-		if (is_array($data) OR is_object($data))
+		switch ($data_type = gettype($data))
 		{
-			if ( ! $this->_redis->sIsMember('_ci_redis_serialized', $id) && ! $this->_redis->sAdd('_ci_redis_serialized', $id))
-			{
+			case 'array':
+			case 'object':
+				$data = serialize($data);
+				break;
+			case 'boolean':
+			case 'integer':
+			case 'double': // Yes, 'double' is returned and NOT 'float'
+			case 'string':
+			case 'NULL':
+				break;
+			case 'resource':
+			default:
 				return FALSE;
-			}
+		}
 
-			isset($this->_serialized[$id]) OR $this->_serialized[$id] = TRUE;
-			$data = serialize($data);
+		if ( ! $this->_redis->hMSet($id, array('__ci_type' => $data_type, '__ci_value' => $data)))
+		{
+			return FALSE;
 		}
-		elseif (isset($this->_serialized[$id]))
+		elseif ($ttl)
 		{
-			$this->_serialized[$id] = NULL;
-			$this->_redis->sRemove('_ci_redis_serialized', $id);
+			$this->_redis->expireAt($id, time() + $ttl);
 		}
 
-		return $this->_redis->set($id, $data, $ttl);
+		return TRUE;
 	}
 
 	// ------------------------------------------------------------------------
@@ -190,23 +209,12 @@ class CI_Cache_redis extends CI_Driver
 	/**
 	 * Delete from cache
 	 *
-	 * @param	string	Cache key
+	 * @param	string	$key	Cache key
 	 * @return	bool
 	 */
 	public function delete($key)
 	{
-		if ($this->_redis->delete($key) !== 1)
-		{
-			return FALSE;
-		}
-
-		if (isset($this->_serialized[$key]))
-		{
-			$this->_serialized[$key] = NULL;
-			$this->_redis->sRemove('_ci_redis_serialized', $key);
-		}
-
-		return TRUE;
+		return ($this->_redis->delete($key) === 1);
 	}
 
 	// ------------------------------------------------------------------------
@@ -220,7 +228,7 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	public function increment($id, $offset = 1)
 	{
-		return $this->_redis->incr($id, $offset);
+		return $this->_redis->hIncrBy($id, 'data', $offset);
 	}
 
 	// ------------------------------------------------------------------------
@@ -234,7 +242,7 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	public function decrement($id, $offset = 1)
 	{
-		return $this->_redis->decr($id, $offset);
+		return $this->_redis->hIncrBy($id, 'data', -$offset);
 	}
 
 	// ------------------------------------------------------------------------
@@ -255,9 +263,9 @@ class CI_Cache_redis extends CI_Driver
 	/**
 	 * Get cache driver info
 	 *
-	 * @param	string	Not supported in Redis.
-	 *			Only included in order to offer a
-	 *			consistent cache API.
+	 * @param	string	$type	Not supported in Redis.
+	 *				Only included in order to offer a
+	 *				consistent cache API.
 	 * @return	array
 	 * @see		Redis::info()
 	 */
@@ -271,7 +279,7 @@ class CI_Cache_redis extends CI_Driver
 	/**
 	 * Get cache metadata
 	 *
-	 * @param	string	Cache key
+	 * @param	string	$key	Cache key
 	 * @return	array
 	 */
 	public function get_metadata($key)
@@ -298,13 +306,7 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	public function is_supported()
 	{
-		if ( ! extension_loaded('redis'))
-		{
-			log_message('debug', 'The Redis extension must be loaded to use Redis cache.');
-			return FALSE;
-		}
-
-		return TRUE;
+		return extension_loaded('redis');
 	}
 
 	// ------------------------------------------------------------------------
diff --git a/system/libraries/Cache/drivers/Cache_wincache.php b/system/libraries/Cache/drivers/Cache_wincache.php
index 9cc6ff016..f296a5e26 100644
--- a/system/libraries/Cache/drivers/Cache_wincache.php
+++ b/system/libraries/Cache/drivers/Cache_wincache.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -52,6 +52,24 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 class CI_Cache_wincache extends CI_Driver {
 
 	/**
+	 * Class constructor
+	 *
+	 * Only present so that an error message is logged
+	 * if APC is not available.
+	 *
+	 * @return	void
+	 */
+	public function __construct()
+	{
+		if ( ! $this->is_supported())
+		{
+			log_message('error', 'Cache: Failed to initialize Wincache; extension not loaded/enabled?');
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
 	 * Get
 	 *
 	 * Look for a value in the cache. If it exists, return the data,
@@ -194,13 +212,6 @@ class CI_Cache_wincache extends CI_Driver {
 	 */
 	public function is_supported()
 	{
-		if ( ! extension_loaded('wincache') OR ! ini_get('wincache.ucenabled'))
-		{
-			log_message('debug', 'The Wincache PHP extension must be loaded to use Wincache Cache.');
-			return FALSE;
-		}
-
-		return TRUE;
+		return (extension_loaded('wincache') && ini_get('wincache.ucenabled'));
 	}
-
 }
diff --git a/system/libraries/Calendar.php b/system/libraries/Calendar.php
index f6a0c39c4..edb0fb4d9 100644
--- a/system/libraries/Calendar.php
+++ b/system/libraries/Calendar.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Libraries
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/calendar.html
+ * @link		https://codeigniter.com/user_guide/libraries/calendar.html
  */
 class CI_Calendar {
 
diff --git a/system/libraries/Cart.php b/system/libraries/Cart.php
deleted file mode 100644
index bf27c6392..000000000
--- a/system/libraries/Cart.php
+++ /dev/null
@@ -1,567 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, 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
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 1.0.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * Shopping Cart Class
- *
- * @package		CodeIgniter
- * @subpackage	Libraries
- * @category	Shopping Cart
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/cart.html
- * @deprecated	3.0.0	This class is too specific for CI.
- */
-class CI_Cart {
-
-	/**
-	 * These are the regular expression rules that we use to validate the product ID and product name
-	 * alpha-numeric, dashes, underscores, or periods
-	 *
-	 * @var string
-	 */
-	public $product_id_rules = '\.a-z0-9_-';
-
-	/**
-	 * These are the regular expression rules that we use to validate the product ID and product name
-	 * alpha-numeric, dashes, underscores, colons or periods
-	 *
-	 * @var string
-	 */
-	public $product_name_rules = '\w \-\.\:';
-
-	/**
-	 * only allow safe product names
-	 *
-	 * @var bool
-	 */
-	public $product_name_safe = TRUE;
-
-	// --------------------------------------------------------------------------
-
-	/**
-	 * Reference to CodeIgniter instance
-	 *
-	 * @var object
-	 */
-	protected $CI;
-
-	/**
-	 * Contents of the cart
-	 *
-	 * @var array
-	 */
-	protected $_cart_contents = array();
-
-	/**
-	 * Shopping Class Constructor
-	 *
-	 * The constructor loads the Session class, used to store the shopping cart contents.
-	 *
-	 * @param	array
-	 * @return	void
-	 */
-	public function __construct($params = array())
-	{
-		// Set the super object to a local variable for use later
-		$this->CI =& get_instance();
-
-		// Are any config settings being passed manually?  If so, set them
-		$config = is_array($params) ? $params : array();
-
-		// Load the Sessions class
-		$this->CI->load->driver('session', $config);
-
-		// Grab the shopping cart array from the session table
-		$this->_cart_contents = $this->CI->session->userdata('cart_contents');
-		if ($this->_cart_contents === NULL)
-		{
-			// No cart exists so we'll set some base values
-			$this->_cart_contents = array('cart_total' => 0, 'total_items' => 0);
-		}
-
-		log_message('info', 'Cart Class Initialized');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert items into the cart and save it to the session table
-	 *
-	 * @param	array
-	 * @return	bool
-	 */
-	public function insert($items = array())
-	{
-		// Was any cart data passed? No? Bah...
-		if ( ! is_array($items) OR count($items) === 0)
-		{
-			log_message('error', 'The insert method must be passed an array containing data.');
-			return FALSE;
-		}
-
-		// You can either insert a single product using a one-dimensional array,
-		// or multiple products using a multi-dimensional one. The way we
-		// determine the array type is by looking for a required array key named "id"
-		// at the top level. If it's not found, we will assume it's a multi-dimensional array.
-
-		$save_cart = FALSE;
-		if (isset($items['id']))
-		{
-			if (($rowid = $this->_insert($items)))
-			{
-				$save_cart = TRUE;
-			}
-		}
-		else
-		{
-			foreach ($items as $val)
-			{
-				if (is_array($val) && isset($val['id']))
-				{
-					if ($this->_insert($val))
-					{
-						$save_cart = TRUE;
-					}
-				}
-			}
-		}
-
-		// Save the cart data if the insert was successful
-		if ($save_cart === TRUE)
-		{
-			$this->_save_cart();
-			return isset($rowid) ? $rowid : TRUE;
-		}
-
-		return FALSE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert
-	 *
-	 * @param	array
-	 * @return	bool
-	 */
-	protected function _insert($items = array())
-	{
-		// Was any cart data passed? No? Bah...
-		if ( ! is_array($items) OR count($items) === 0)
-		{
-			log_message('error', 'The insert method must be passed an array containing data.');
-			return FALSE;
-		}
-
-		// --------------------------------------------------------------------
-
-		// Does the $items array contain an id, quantity, price, and name?  These are required
-		if ( ! isset($items['id'], $items['qty'], $items['price'], $items['name']))
-		{
-			log_message('error', 'The cart array must contain a product ID, quantity, price, and name.');
-			return FALSE;
-		}
-
-		// --------------------------------------------------------------------
-
-		// Prep the quantity. It can only be a number.  Duh... also trim any leading zeros
-		$items['qty'] = (float) $items['qty'];
-
-		// If the quantity is zero or blank there's nothing for us to do
-		if ($items['qty'] == 0)
-		{
-			return FALSE;
-		}
-
-		// --------------------------------------------------------------------
-
-		// Validate the product ID. It can only be alpha-numeric, dashes, underscores or periods
-		// Not totally sure we should impose this rule, but it seems prudent to standardize IDs.
-		// Note: These can be user-specified by setting the $this->product_id_rules variable.
-		if ( ! preg_match('/^['.$this->product_id_rules.']+$/i', $items['id']))
-		{
-			log_message('error', 'Invalid product ID.  The product ID can only contain alpha-numeric characters, dashes, and underscores');
-			return FALSE;
-		}
-
-		// --------------------------------------------------------------------
-
-		// Validate the product name. It can only be alpha-numeric, dashes, underscores, colons or periods.
-		// Note: These can be user-specified by setting the $this->product_name_rules variable.
-		if ($this->product_name_safe && ! preg_match('/^['.$this->product_name_rules.']+$/i'.(UTF8_ENABLED ? 'u' : ''), $items['name']))
-		{
-			log_message('error', 'An invalid name was submitted as the product name: '.$items['name'].' The name can only contain alpha-numeric characters, dashes, underscores, colons, and spaces');
-			return FALSE;
-		}
-
-		// --------------------------------------------------------------------
-
-		// Prep the price. Remove leading zeros and anything that isn't a number or decimal point.
-		$items['price'] = (float) $items['price'];
-
-		// We now need to create a unique identifier for the item being inserted into the cart.
-		// Every time something is added to the cart it is stored in the master cart array.
-		// Each row in the cart array, however, must have a unique index that identifies not only
-		// a particular product, but makes it possible to store identical products with different options.
-		// For example, what if someone buys two identical t-shirts (same product ID), but in
-		// different sizes?  The product ID (and other attributes, like the name) will be identical for
-		// both sizes because it's the same shirt. The only difference will be the size.
-		// Internally, we need to treat identical submissions, but with different options, as a unique product.
-		// Our solution is to convert the options array to a string and MD5 it along with the product ID.
-		// This becomes the unique "row ID"
-		if (isset($items['options']) && count($items['options']) > 0)
-		{
-			$rowid = md5($items['id'].serialize($items['options']));
-		}
-		else
-		{
-			// No options were submitted so we simply MD5 the product ID.
-			// Technically, we don't need to MD5 the ID in this case, but it makes
-			// sense to standardize the format of array indexes for both conditions
-			$rowid = md5($items['id']);
-		}
-
-		// --------------------------------------------------------------------
-
-		// Now that we have our unique "row ID", we'll add our cart items to the master array
-		// grab quantity if it's already there and add it on
-		$old_quantity = isset($this->_cart_contents[$rowid]['qty']) ? (int) $this->_cart_contents[$rowid]['qty'] : 0;
-
-		// Re-create the entry, just to make sure our index contains only the data from this submission
-		$items['rowid'] = $rowid;
-		$items['qty'] += $old_quantity;
-		$this->_cart_contents[$rowid] = $items;
-
-		return $rowid;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update the cart
-	 *
-	 * This function permits the quantity of a given item to be changed.
-	 * Typically it is called from the "view cart" page if a user makes
-	 * changes to the quantity before checkout. That array must contain the
-	 * product ID and quantity for each item.
-	 *
-	 * @param	array
-	 * @return	bool
-	 */
-	public function update($items = array())
-	{
-		// Was any cart data passed?
-		if ( ! is_array($items) OR count($items) === 0)
-		{
-			return FALSE;
-		}
-
-		// You can either update a single product using a one-dimensional array,
-		// or multiple products using a multi-dimensional one.  The way we
-		// determine the array type is by looking for a required array key named "rowid".
-		// If it's not found we assume it's a multi-dimensional array
-		$save_cart = FALSE;
-		if (isset($items['rowid']))
-		{
-			if ($this->_update($items) === TRUE)
-			{
-				$save_cart = TRUE;
-			}
-		}
-		else
-		{
-			foreach ($items as $val)
-			{
-				if (is_array($val) && isset($val['rowid']))
-				{
-					if ($this->_update($val) === TRUE)
-					{
-						$save_cart = TRUE;
-					}
-				}
-			}
-		}
-
-		// Save the cart data if the insert was successful
-		if ($save_cart === TRUE)
-		{
-			$this->_save_cart();
-			return TRUE;
-		}
-
-		return FALSE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update the cart
-	 *
-	 * This function permits changing item properties.
-	 * Typically it is called from the "view cart" page if a user makes
-	 * changes to the quantity before checkout. That array must contain the
-	 * rowid and quantity for each item.
-	 *
-	 * @param	array
-	 * @return	bool
-	 */
-	protected function _update($items = array())
-	{
-		// Without these array indexes there is nothing we can do
-		if ( ! isset($items['rowid'], $this->_cart_contents[$items['rowid']]))
-		{
-			return FALSE;
-		}
-
-		// Prep the quantity
-		if (isset($items['qty']))
-		{
-			$items['qty'] = (float) $items['qty'];
-			// Is the quantity zero?  If so we will remove the item from the cart.
-			// If the quantity is greater than zero we are updating
-			if ($items['qty'] == 0)
-			{
-				unset($this->_cart_contents[$items['rowid']]);
-				return TRUE;
-			}
-		}
-
-		// find updatable keys
-		$keys = array_intersect(array_keys($this->_cart_contents[$items['rowid']]), array_keys($items));
-		// if a price was passed, make sure it contains valid data
-		if (isset($items['price']))
-		{
-			$items['price'] = (float) $items['price'];
-		}
-
-		// product id & name shouldn't be changed
-		foreach (array_diff($keys, array('id', 'name')) as $key)
-		{
-			$this->_cart_contents[$items['rowid']][$key] = $items[$key];
-		}
-
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Save the cart array to the session DB
-	 *
-	 * @return	bool
-	 */
-	protected function _save_cart()
-	{
-		// Let's add up the individual prices and set the cart sub-total
-		$this->_cart_contents['total_items'] = $this->_cart_contents['cart_total'] = 0;
-		foreach ($this->_cart_contents as $key => $val)
-		{
-			// We make sure the array contains the proper indexes
-			if ( ! is_array($val) OR ! isset($val['price'], $val['qty']))
-			{
-				continue;
-			}
-
-			$this->_cart_contents['cart_total'] += ($val['price'] * $val['qty']);
-			$this->_cart_contents['total_items'] += $val['qty'];
-			$this->_cart_contents[$key]['subtotal'] = ($this->_cart_contents[$key]['price'] * $this->_cart_contents[$key]['qty']);
-		}
-
-		// Is our cart empty? If so we delete it from the session
-		if (count($this->_cart_contents) <= 2)
-		{
-			$this->CI->session->unset_userdata('cart_contents');
-
-			// Nothing more to do... coffee time!
-			return FALSE;
-		}
-
-		// If we made it this far it means that our cart has data.
-		// Let's pass it to the Session class so it can be stored
-		$this->CI->session->set_userdata(array('cart_contents' => $this->_cart_contents));
-
-		// Woot!
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Cart Total
-	 *
-	 * @return	int
-	 */
-	public function total()
-	{
-		return $this->_cart_contents['cart_total'];
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Remove Item
-	 *
-	 * Removes an item from the cart
-	 *
-	 * @param	int
-	 * @return	bool
-	 */
-	 public function remove($rowid)
-	 {
-		// unset & save
-		unset($this->_cart_contents[$rowid]);
-		$this->_save_cart();
-		return TRUE;
-	 }
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Total Items
-	 *
-	 * Returns the total item count
-	 *
-	 * @return	int
-	 */
-	public function total_items()
-	{
-		return $this->_cart_contents['total_items'];
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Cart Contents
-	 *
-	 * Returns the entire cart array
-	 *
-	 * @param	bool
-	 * @return	array
-	 */
-	public function contents($newest_first = FALSE)
-	{
-		// do we want the newest first?
-		$cart = ($newest_first) ? array_reverse($this->_cart_contents) : $this->_cart_contents;
-
-		// Remove these so they don't create a problem when showing the cart table
-		unset($cart['total_items']);
-		unset($cart['cart_total']);
-
-		return $cart;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Get cart item
-	 *
-	 * Returns the details of a specific item in the cart
-	 *
-	 * @param	string	$row_id
-	 * @return	array
-	 */
-	public function get_item($row_id)
-	{
-		return (in_array($row_id, array('total_items', 'cart_total'), TRUE) OR ! isset($this->_cart_contents[$row_id]))
-			? FALSE
-			: $this->_cart_contents[$row_id];
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Has options
-	 *
-	 * Returns TRUE if the rowid passed to this function correlates to an item
-	 * that has options associated with it.
-	 *
-	 * @param	string	$row_id = ''
-	 * @return	bool
-	 */
-	public function has_options($row_id = '')
-	{
-		return (isset($this->_cart_contents[$row_id]['options']) && count($this->_cart_contents[$row_id]['options']) !== 0);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Product options
-	 *
-	 * Returns the an array of options, for a particular product row ID
-	 *
-	 * @param	string	$row_id = ''
-	 * @return	array
-	 */
-	public function product_options($row_id = '')
-	{
-		return isset($this->_cart_contents[$row_id]['options']) ? $this->_cart_contents[$row_id]['options'] : array();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Format Number
-	 *
-	 * Returns the supplied number with commas and a decimal point.
-	 *
-	 * @param	float
-	 * @return	string
-	 */
-	public function format_number($n = '')
-	{
-		return ($n === '') ? '' : number_format( (float) $n, 2, '.', ',');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Destroy the cart
-	 *
-	 * Empties the cart and kills the session
-	 *
-	 * @return	void
-	 */
-	public function destroy()
-	{
-		$this->_cart_contents = array('cart_total' => 0, 'total_items' => 0);
-		$this->CI->session->unset_userdata('cart_contents');
-	}
-
-}
diff --git a/system/libraries/Driver.php b/system/libraries/Driver.php
index da4c548e6..00e8416f9 100644
--- a/system/libraries/Driver.php
+++ b/system/libraries/Driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 459c8f590..1483f2203 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Libraries
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/email.html
+ * @link		https://codeigniter.com/user_guide/libraries/email.html
  */
 class CI_Email {
 
@@ -150,13 +150,6 @@ class CI_Email {
 	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)
-
-	/**
 	 * Alternative message (for HTML messages only)
 	 *
 	 * @var	string
@@ -168,7 +161,7 @@ class CI_Email {
 	 *
 	 * @var	bool
 	 */
-	public $validate	= FALSE;
+	public $validate	= TRUE;
 
 	/**
 	 * X-Priority header value.
@@ -233,13 +226,6 @@ class CI_Email {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Whether PHP is running in safe mode. Initialized by the class constructor.
-	 *
-	 * @var	bool
-	 */
-	protected $_safe_mode		= FALSE;
-
-	/**
 	 * Subject header
 	 *
 	 * @var	string
@@ -261,20 +247,6 @@ class CI_Email {
 	protected $_finalbody		= '';
 
 	/**
-	 * multipart/alternative boundary
-	 *
-	 * @var	string
-	 */
-	protected $_alt_boundary	= '';
-
-	/**
-	 * Attachment boundary
-	 *
-	 * @var	string
-	 */
-	protected $_atc_boundary	= '';
-
-	/**
 	 * Final headers to send
 	 *
 	 * @var	string
@@ -395,6 +367,13 @@ class CI_Email {
 		5 => '5 (Lowest)'
 	);
 
+	/**
+	 * mbstring.func_override flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_override;
+
 	// --------------------------------------------------------------------
 
 	/**
@@ -408,18 +387,9 @@ class CI_Email {
 	public function __construct(array $config = array())
 	{
 		$this->charset = config_item('charset');
+		$this->initialize($config);
 
-		if (count($config) > 0)
-		{
-			$this->initialize($config);
-		}
-		else
-		{
-			$this->_smtp_auth = ! ($this->smtp_user === '' && $this->smtp_pass === '');
-		}
-
-		$this->_safe_mode = ( ! is_php('5.4') && ini_get('safe_mode'));
-		$this->charset = strtoupper($this->charset);
+		isset(self::$func_override) OR self::$func_override = (extension_loaded('mbstring') && ini_get('mbstring.func_override'));
 
 		log_message('info', 'Email Class Initialized');
 	}
@@ -427,28 +397,15 @@ class CI_Email {
 	// --------------------------------------------------------------------
 
 	/**
-	 * 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 +422,9 @@ 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 +450,6 @@ 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)
@@ -574,14 +530,18 @@ class CI_Email {
 			$this->validate_email($this->_str_to_array($replyto));
 		}
 
-		if ($name === '')
-		{
-			$name = $replyto;
-		}
-
-		if (strpos($name, '"') !== 0)
+		if ($name !== '')
 		{
-			$name = '"'.$name.'"';
+			// only use Q encoding if there are characters that would require it
+			if ( ! preg_match('/[\200-\377]/', $name))
+			{
+				// add slashes for non-printing characters, slashes, and double quotes, and surround it in double quotes
+				$name = '"'.addcslashes($name, "\0..\37\177'\"\\").'"';
+			}
+			else
+			{
+				$name = $this->_prep_q_encoding($name);
+			}
 		}
 
 		$this->set_header('Reply-To', $name.' <'.$replyto.'>');
@@ -707,18 +667,6 @@ class CI_Email {
 	public function message($body)
 	{
 		$this->_body = rtrim(str_replace("\r", '', $body));
-
-		/* strip slashes only if magic quotes is ON
-		   if we do it with magic quotes OFF, it strips real, user-inputted chars.
-
-		   NOTE: In PHP 5.4 get_magic_quotes_gpc() will always return 0 and
-			 it will probably not exist in future versions at all.
-		*/
-		if ( ! is_php('5.4') && get_magic_quotes_gpc())
-		{
-			$this->_body = stripslashes($this->_body);
-		}
-
 		return $this;
 	}
 
@@ -762,7 +710,8 @@ 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 $this;
@@ -780,15 +729,11 @@ class CI_Email {
 	 */
 	public function attachment_cid($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'];
 			}
@@ -933,19 +878,6 @@ class CI_Email {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set Message Boundary
-	 *
-	 * @return	void
-	 */
-	protected function _set_boundaries()
-	{
-		$this->_alt_boundary = 'B_ALT_'.uniqid(''); // multipart/alternative
-		$this->_atc_boundary = 'B_ATC_'.uniqid(''); // attachment boundary
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Get the Message ID
 	 *
 	 * @return	string
@@ -1012,9 +944,9 @@ class CI_Email {
 	{
 		if ($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';
 		}
@@ -1093,7 +1025,7 @@ 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($email, FILTER_VALIDATE_EMAIL);
@@ -1210,7 +1142,7 @@ class CI_Email {
 		{
 			// Is the line within the allowed character count?
 			// If so we'll join it to the output and continue
-			if (mb_strlen($line) <= $charlim)
+			if (self::strlen($line) <= $charlim)
 			{
 				$output .= $line.$this->newline;
 				continue;
@@ -1226,10 +1158,10 @@ 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
@@ -1258,10 +1190,11 @@ 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]);
@@ -1320,7 +1253,6 @@ class CI_Email {
 			$this->_body = $this->word_wrap($this->_body);
 		}
 
-		$this->_set_boundaries();
 		$this->_write_headers();
 
 		$hdr = ($this->_get_protocol() === 'mail') ? $this->newline : '';
@@ -1328,7 +1260,7 @@ 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();
@@ -1345,7 +1277,7 @@ class CI_Email {
 
 				return;
 
-			case 'html' :
+			case 'html':
 
 				if ($this->send_multipart === FALSE)
 				{
@@ -1354,14 +1286,16 @@ 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;
@@ -1380,14 +1314,15 @@ 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')
 				{
@@ -1396,59 +1331,83 @@ 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);
+
+				break;
+			case 'html-attach':
 
-				$hdr .= 'Content-Type: multipart/'.$this->multipart.'; boundary="'.$this->_atc_boundary.'"';
+				$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.$this->newline;
-
-			break;
-		}
+					.'--'.$alt_boundary.'--'.$this->newline.$this->newline;
 
-		$attachment = array();
-		for ($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];
+				if ( ! empty($rel_boundary))
+				{
+					$body .= $this->newline.$this->newline;
+					$this->_append_attachments($body, $rel_boundary, 'related');
+				}
 
-			$attachment[$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'].'>'.$this->newline);
+				// multipart/mixed attachments
+				if ( ! empty($atc_boundary))
+				{
+					$body .= $this->newline.$this->newline;
+					$this->_append_attachments($body, $atc_boundary, 'mixed');
+				}
 
-			$attachment[$z++] = $this->_attachments[$i]['content'];
+				break;
 		}
 
-		$body .= implode($this->newline, $attachment).$this->newline.'--'.$this->_atc_boundary.'--';
 		$this->_finalbody = ($this->_get_protocol() === 'mail')
 			? $body
 			: $hdr.$this->newline.$this->newline.$body;
@@ -1458,6 +1417,58 @@ 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
 	 *
@@ -1469,6 +1480,20 @@ class CI_Email {
 	 */
 	protected function _prep_quoted_printable($str)
 	{
+		// ASCII code numbers for "safe" characters that can always be
+		// used literally, without encoding, as described in RFC 2049.
+		// http://www.ietf.org/rfc/rfc2049.txt
+		static $ascii_safe_chars = array(
+			// ' (  )   +   ,   -   .   /   :   =   ?
+			39, 40, 41, 43, 44, 45, 46, 47, 58, 61, 63,
+			// numbers
+			48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
+			// upper-case letters
+			65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
+			// lower-case letters
+			97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122
+		);
+
 		// We are intentionally wrapping so mail servers will encode characters
 		// properly and MUAs will behave, so {unwrap} must go!
 		$str = str_replace(array('{unwrap}', '{/unwrap}'), '', $str);
@@ -1479,14 +1504,7 @@ class CI_Email {
 		// which only works with "\n".
 		if ($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
@@ -1503,7 +1521,7 @@ 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
@@ -1516,18 +1534,29 @@ class CI_Email {
 				$ascii = ord($char);
 
 				// Convert spaces and tabs but only if it's the end of the line
-				if ($i === ($length - 1) && ($ascii === 32 OR $ascii === 9))
+				if ($ascii === 32 OR $ascii === 9)
 				{
-					$char = $escape.sprintf('%02s', dechex($ascii));
+					if ($i === ($length - 1))
+					{
+						$char = $escape.sprintf('%02s', dechex($ascii));
+					}
 				}
-				elseif ($ascii === 61) // encode = signs
+				// DO NOT move this below the $ascii_safe_chars line!
+				//
+				// = (equals) signs are allowed by RFC2049, but must be encoded
+				// as they are the encoding delimiter!
+				elseif ($ascii === 61)
 				{
 					$char = $escape.strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
 				}
+				elseif ( ! in_array($ascii, $ascii_safe_chars, TRUE))
+				{
+					$char = $escape.strtoupper(sprintf('%02s', dechex($ascii)));
+				}
 
 				// 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 = '';
@@ -1542,7 +1571,7 @@ 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);
 	}
 
 	// --------------------------------------------------------------------
@@ -1563,11 +1592,10 @@ class CI_Email {
 
 		if ($this->charset === 'UTF-8')
 		{
-			if (MB_ENABLED === TRUE)
-			{
-				return mb_encode_mimeheader($str, $this->charset, 'Q', $this->crlf);
-			}
-			elseif (ICONV_ENABLED === TRUE)
+			// Note: We used to have mb_encode_mimeheader() as the first choice
+			//       here, but it turned out to be buggy and unreliable. DO NOT
+			//       re-add it! -- Narf
+			if (ICONV_ENABLED === TRUE)
 			{
 				$output = @iconv_mime_encode('', $str,
 					array(
@@ -1585,18 +1613,22 @@ class CI_Email {
 					// iconv_mime_encode() will always put a header field name.
 					// We've passed it an empty one, but it still prepends our
 					// encoded string with ': ', so we need to strip it.
-					return substr($output, 2);
+					return self::substr($output, 2);
 				}
 
 				$chars = iconv_strlen($str, 'UTF-8');
 			}
+			elseif (MB_ENABLED === TRUE)
+			{
+				$chars = mb_strlen($str, 'UTF-8');
+			}
 		}
 
 		// 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))
@@ -1604,11 +1636,11 @@ 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
 			{
@@ -1701,14 +1733,14 @@ 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);
 			}
 		}
 
@@ -1791,6 +1823,33 @@ 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()
 	 *
 	 * @return	bool
@@ -1802,16 +1861,18 @@ 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 ( ! $this->_validate_email_for_shell($from))
 		{
 			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str);
 		}
-		else
-		{
-			// most documentation of sendmail using the "-f" flag lacks a space after it, however
-			// we've encountered servers that seem to require it to be in place.
-			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$this->clean_email($this->_headers['Return-Path']));
-		}
+
+		// most documentation of sendmail using the "-f" flag lacks a space after it, however
+		// we've encountered servers that seem to require it to be in place.
+		return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$from);
 	}
 
 	// --------------------------------------------------------------------
@@ -1823,14 +1884,22 @@ class CI_Email {
 	 */
 	protected function _send_with_sendmail()
 	{
+		// _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(
-						$this->mailpath.' -oi -f '.$this->clean_email($this->_headers['From'])
-							.' -t -r '.$this->clean_email($this->_headers['Return-Path'])
-						, 'w'))
-		) // server probably has popen disabled, so nothing we can do to get a verbose error.
+		if ( ! function_usable('popen')	OR FALSE === ($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;
 		}
 
@@ -1869,20 +1938,29 @@ class CI_Email {
 			return FALSE;
 		}
 
-		$this->_send_command('from', $this->clean_email($this->_headers['From']));
+		if ( ! $this->_send_command('from', $this->clean_email($this->_headers['From'])))
+		{
+			$this->_smtp_end();
+			return FALSE;
+		}
 
 		foreach ($this->_recipients as $val)
 		{
-			$this->_send_command('to', $val);
+			if ( ! $this->_send_command('to', $val))
+			{
+				$this->_smtp_end();
+				return FALSE;
+			}
 		}
 
 		if (count($this->_cc_array) > 0)
 		{
 			foreach ($this->_cc_array as $val)
 			{
-				if ($val !== '')
+				if ($val !== '' && ! $this->_send_command('to', $val))
 				{
-					$this->_send_command('to', $val);
+					$this->_smtp_end();
+					return FALSE;
 				}
 			}
 		}
@@ -1891,14 +1969,19 @@ class CI_Email {
 		{
 			foreach ($this->_bcc_array as $val)
 			{
-				if ($val !== '')
+				if ($val !== '' && ! $this->_send_command('to', $val))
 				{
-					$this->_send_command('to', $val);
+					$this->_smtp_end();
+					return FALSE;
 				}
 			}
 		}
 
-		$this->_send_command('data');
+		if ( ! $this->_send_command('data'))
+		{
+			$this->_smtp_end();
+			return FALSE;
+		}
 
 		// perform dot transformation on any lines that begin with a dot
 		$this->_send_data($this->_header_str.preg_replace('/^\./m', '..$1', $this->_finalbody));
@@ -1906,30 +1989,38 @@ 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')
+			: $this->_send_command('quit');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * SMTP Connect
 	 *
 	 * @return	string
@@ -1982,7 +2073,7 @@ class CI_Email {
 	 *
 	 * @param	string
 	 * @param	string
-	 * @return	string
+	 * @return	bool
 	 */
 	protected function _send_command($cmd, $data = '')
 	{
@@ -2045,7 +2136,7 @@ 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;
@@ -2113,6 +2204,11 @@ class CI_Email {
 			return FALSE;
 		}
 
+		if ($this->smtp_keepalive)
+		{
+			$this->_smtp_auth = FALSE;
+		}
+
 		return TRUE;
 	}
 
@@ -2127,9 +2223,9 @@ 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;
 			}
@@ -2302,4 +2398,52 @@ 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::$func_override)
+			? mb_strlen($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_override)
+		{
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length)
+			? substr($str, $start, $length)
+			: substr($str, $start);
+	}
 }
diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
index a46d4f462..46f374726 100644
--- a/system/libraries/Encrypt.php
+++ b/system/libraries/Encrypt.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Libraries
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/encryption.html
+ * @link		https://codeigniter.com/user_guide/libraries/encryption.html
  */
 class CI_Encrypt {
 
@@ -198,7 +198,7 @@ class CI_Encrypt {
 	 * This allows for backwards compatibility and a method to transition to the
 	 * new encryption algorithms.
 	 *
-	 * For more details, see http://codeigniter.com/user_guide/installation/upgrade_200.html#encryption
+	 * For more details, see https://codeigniter.com/user_guide/installation/upgrade_200.html#encryption
 	 *
 	 * @param	string
 	 * @param	int		(mcrypt mode constant)
diff --git a/system/libraries/Encryption.php b/system/libraries/Encryption.php
index f3e039881..6799d0fef 100644
--- a/system/libraries/Encryption.php
+++ b/system/libraries/Encryption.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Libraries
  * @author		Andrey Andreev
- * @link		http://codeigniter.com/user_guide/libraries/encryption.html
+ * @link		https://codeigniter.com/user_guide/libraries/encryption.html
  */
 class CI_Encryption {
 
@@ -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'] && ! $this->_drivers['openssl'])
@@ -337,9 +335,28 @@ class CI_Encryption {
 	 */
 	public function create_key($length)
 	{
-		return ($this->_driver === 'mcrypt')
-			? mcrypt_create_iv($length, MCRYPT_DEV_URANDOM)
-			: openssl_random_pseudo_bytes($length);
+		if (function_exists('random_bytes'))
+		{
+			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);
+		}
+
+		$is_secure = NULL;
+		$key = openssl_random_pseudo_bytes($length, $is_secure);
+		return ($is_secure === TRUE)
+			? $key
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -395,7 +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)
@@ -458,14 +475,14 @@ 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(
 			$data,
 			$params['handle'],
 			$params['key'],
-			1, // DO NOT TOUCH!
+			OPENSSL_RAW_DATA,
 			$iv
 		);
 
@@ -624,7 +641,7 @@ class CI_Encryption {
 				$data,
 				$params['handle'],
 				$params['key'],
-				1, // DO NOT TOUCH!
+				OPENSSL_RAW_DATA,
 				$iv
 			);
 	}
@@ -890,7 +907,7 @@ class CI_Encryption {
 	 * Byte-safe strlen()
 	 *
 	 * @param	string	$str
-	 * @return	integer
+	 * @return	int
 	 */
 	protected static function strlen($str)
 	{
@@ -913,9 +930,6 @@ class CI_Encryption {
 	{
 		if (self::$func_override)
 		{
-			// mb_substr($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');
 		}
 
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index d9ecc45f9..7be0b949d 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Validation
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/form_validation.html
+ * @link		https://codeigniter.com/user_guide/libraries/form_validation.html
  */
 class CI_Form_validation {
 
@@ -164,7 +164,7 @@ class CI_Form_validation {
 	 * @param	array	$errors
 	 * @return	CI_Form_validation
 	 */
-	public function set_rules($field, $label = '', $rules = array(), $errors = array())
+	public function set_rules($field, $label = null, $rules = null, $errors = array())
 	{
 		// No reason to set rules if we have no POST data
 		// or a validation array has not been specified
@@ -197,6 +197,10 @@ class CI_Form_validation {
 
 			return $this;
 		}
+		elseif ( ! isset($rules))
+		{
+			throw new BadMethodCallException('Form_validation: set_rules() called without a $rules parameter');
+		}
 
 		// No fields or no rules? Nothing to do...
 		if ( ! is_string($field) OR $field === '' OR empty($rules))
@@ -211,7 +215,7 @@ class CI_Form_validation {
 				return $this;
 			}
 
-			$rules = explode('|', $rules);
+			$rules = preg_split('/\|(?![^\[]*\])/', $rules);
 		}
 
 		// If the field label wasn't passed we use the field name
@@ -415,12 +419,9 @@ class CI_Form_validation {
 	 */
 	public function run($group = '')
 	{
-		// Do we even have any data to process?  Mm?
-		$validation_array = empty($this->validation_data) ? $_POST : $this->validation_data;
-		if (count($validation_array) === 0)
-		{
-			return FALSE;
-		}
+		$validation_array = empty($this->validation_data)
+			? $_POST
+			: $this->validation_data;
 
 		// Does the _field_data array containing the validation rules exist?
 		// If not, we look to see if they were assigned via a config file
@@ -453,7 +454,7 @@ class CI_Form_validation {
 		$this->CI->lang->load('form_validation');
 
 		// Cycle through the rules for each field and match the corresponding $validation_data item
-		foreach ($this->_field_data as $field => $row)
+		foreach ($this->_field_data as $field => &$row)
 		{
 			// Fetch the data from the validation_data array item and cache it in the _field_data array.
 			// Depending on whether the field name is an array or a string will determine where we get it from.
@@ -470,7 +471,7 @@ class CI_Form_validation {
 		// Execute validation rules
 		// Note: A second foreach (for now) is required in order to avoid false-positives
 		//	 for rules like 'matches', which correlate to other validation fields.
-		foreach ($this->_field_data as $field => $row)
+		foreach ($this->_field_data as $field => &$row)
 		{
 			// Don't try to validate if we have no rules set
 			if (empty($row['rules']))
@@ -478,7 +479,7 @@ class CI_Form_validation {
 				continue;
 			}
 
-			$this->_execute($row, $row['rules'], $this->_field_data[$field]['postdata']);
+			$this->_execute($row, $row['rules'], $row['postdata']);
 		}
 
 		// Did we end up with any errors?
@@ -489,7 +490,7 @@ class CI_Form_validation {
 		}
 
 		// Now we need to re-set the POST data with the new, processed data
-		$this->_reset_post_array();
+		empty($this->validation_data) && $this->_reset_post_array();
 
 		return ($total_errors === 0);
 	}
@@ -497,6 +498,63 @@ 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 $_POST array index until the data is found
 	 *
 	 * @param	array
@@ -530,10 +588,7 @@ class CI_Form_validation {
 			{
 				if ($row['is_array'] === FALSE)
 				{
-					if (isset($_POST[$row['field']]))
-					{
-						$_POST[$row['field']] = $row['postdata'];
-					}
+					isset($_POST[$field]) && $_POST[$field] = $row['postdata'];
 				}
 				else
 				{
@@ -553,20 +608,7 @@ class CI_Form_validation {
 						}
 					}
 
-					if (is_array($row['postdata']))
-					{
-						$array = array();
-						foreach ($row['postdata'] as $k => $v)
-						{
-							$array[$k] = $v;
-						}
-
-						$post_ref = $array;
-					}
-					else
-					{
-						$post_ref = $row['postdata'];
-					}
+					$post_ref = $row['postdata'];
 				}
 			}
 		}
@@ -586,7 +628,10 @@ class CI_Form_validation {
 	protected function _execute($row, $rules, $postdata = NULL, $cycles = 0)
 	{
 		// If the $_POST data is an array we will run a recursive call
-		if (is_array($postdata))
+		//
+		// Note: We MUST check if the array is empty or not!
+		//       Otherwise empty arrays will always pass validation.
+		if (is_array($postdata) && ! empty($postdata))
 		{
 			foreach ($postdata as $key => $val)
 			{
@@ -596,84 +641,7 @@ 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', $rules) ? 'required' : 'isset';
-
-				// Check if a custom message is defined
-				if (isset($this->_field_data[$row['field']]['errors'][$type]))
-				{
-					$line = $this->_field_data[$row['field']]['errors'][$type];
-				}
-				elseif (isset($this->_error_messages[$type]))
-				{
-					$line = $this->_error_messages[$type];
-				}
-				elseif (FALSE === ($line = $this->CI->lang->line('form_validation_'.$type))
-					// DEPRECATED support for non-prefixed keys
-					&& FALSE === ($line = $this->CI->lang->line($type, FALSE)))
-				{
-					$line = 'The field was not set';
-				}
-
-				// 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;
@@ -732,6 +700,17 @@ 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)
 			{
@@ -770,12 +749,6 @@ 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))
 			{
@@ -823,23 +796,9 @@ class CI_Form_validation {
 				{
 					$line = $this->CI->lang->line('form_validation_error_message_not_set').'(Anonymous function)';
 				}
-				// Check if a custom message is defined
-				elseif (isset($this->_field_data[$row['field']]['errors'][$rule]))
-				{
-					$line = $this->_field_data[$row['field']]['errors'][$rule];
-				}
-				elseif ( ! isset($this->_error_messages[$rule]))
-				{
-					if (FALSE === ($line = $this->CI->lang->line('form_validation_'.$rule))
-						// DEPRECATED support for non-prefixed keys
-						&& FALSE === ($line = $this->CI->lang->line($rule, FALSE)))
-					{
-						$line = $this->CI->lang->line('form_validation_error_message_not_set').'('.$rule.')';
-					}
-				}
 				else
 				{
-					$line = $this->_error_messages[$rule];
+					$line = $this->_get_error_message($rule, $row['field']);
 				}
 
 				// Is the parameter we are inserting into the error message the name
@@ -868,6 +827,40 @@ class CI_Form_validation {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Get the error message for the rule
+	 *
+	 * @param 	string $rule 	The rule name
+	 * @param 	string $field	The field name
+	 * @return 	string
+	 */
+	protected function _get_error_message($rule, $field)
+	{
+		// check if a custom message is defined through validation config row.
+		if (isset($this->_field_data[$field]['errors'][$rule]))
+		{
+			return $this->_field_data[$field]['errors'][$rule];
+		}
+		// check if a custom message has been set using the set_message() function
+		elseif (isset($this->_error_messages[$rule]))
+		{
+			return $this->_error_messages[$rule];
+		}
+		elseif (FALSE !== ($line = $this->CI->lang->line('form_validation_'.$rule)))
+		{
+			return $line;
+		}
+		// DEPRECATED support for non-prefixed keys, lang file again
+		elseif (FALSE !== ($line = $this->CI->lang->line($rule, FALSE)))
+		{
+			return $line;
+		}
+
+		return $this->CI->lang->line('form_validation_error_message_not_set').'('.$rule.')';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Translate a field name
 	 *
 	 * @param	string	the field name
@@ -1065,7 +1058,9 @@ 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) !== '');
 	}
 
 	// --------------------------------------------------------------------
@@ -1209,7 +1204,7 @@ 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;
 			}
@@ -1217,18 +1212,15 @@ class CI_Form_validation {
 			$str = $matches[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', '=='))
+		// PHP 7 accepts IPv6 addresses within square brackets as hostnames,
+		// but it appears that the PR that came in with https://bugs.php.net/bug.php?id=68039
+		// was never merged into a PHP 5 branch ... https://3v4l.org/8PsSN
+		if (preg_match('/^\[([^\]]+)\]/', $str, $matches) && ! is_php('7') && filter_var($matches[1], FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) !== FALSE)
 		{
-			sscanf($str, 'http://%[^/]', $host);
-			$str = substr_replace($str, strtr($host, array('_' => '-', '-' => '_')), 7, strlen($host));
+			$str = 'ipv6.host'.substr($str, strlen($matches[1]) + 2);
 		}
 
-		return (filter_var($str, FILTER_VALIDATE_URL) !== FALSE);
+		return (filter_var('http://'.$str, FILTER_VALIDATE_URL) !== FALSE);
 	}
 
 	// --------------------------------------------------------------------
@@ -1241,9 +1233,9 @@ 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);
@@ -1292,6 +1284,31 @@ class CI_Form_validation {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Validate MAC address
+	 *
+	 * @param	string	$mac
+	 * @return	bool
+	 */
+	public function valid_mac($mac)
+	{
+		if ( ! is_php('5.5'))
+		{
+			// Most common format, with either dash or colon delimiters
+			if (preg_match('#\A[0-9a-f]{2}(?<delimiter>[:-])([0-9a-f]{2}(?P=delimiter)){4}[0-9a-f]{2}\z#i', $mac))
+			{
+				return TRUE;
+			}
+
+			// The less common format; e.g. 0123.4567.89ab
+			return (bool) preg_match('#((\A|\.)[0-9a-f]{4}){3}\z#i', $mac);
+		}
+
+		return (bool) filter_var($mac, FILTER_VALIDATE_MAC);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Alpha
 	 *
 	 * @param	string
@@ -1496,37 +1513,6 @@ class CI_Form_validation {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Prep data for form
-	 *
-	 * This function allows HTML to be safely shown in a form.
-	 * Special characters are converted.
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function prep_for_form($data = '')
-	{
-		if ($this->_safe_form_data === FALSE OR empty($data))
-		{
-			return $data;
-		}
-
-		if (is_array($data))
-		{
-			foreach ($data as $key => $val)
-			{
-				$data[$key] = $this->prep_for_form($val);
-			}
-
-			return $data;
-		}
-
-		return str_replace(array("'", '"', '<', '>'), array('&#39;', '&quot;', '&lt;', '&gt;'), stripslashes($data));
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Prep URL
 	 *
 	 * @param	string
@@ -1534,12 +1520,7 @@ class CI_Form_validation {
 	 */
 	public function prep_url($str = '')
 	{
-		if ($str === 'http://' OR $str === '')
-		{
-			return '';
-		}
-
-		if (strpos($str, 'http://') !== 0 && strpos($str, 'https://') !== 0)
+		if ($str !== '' && stripos($str, 'http://') !== 0 && stripos($str, 'https://') !== 0)
 		{
 			return 'http://'.$str;
 		}
@@ -1586,7 +1567,6 @@ class CI_Form_validation {
 	public function reset_validation()
 	{
 		$this->_field_data = array();
-		$this->_config_rules = array();
 		$this->_error_array = array();
 		$this->_error_messages = array();
 		$this->error_string = '';
diff --git a/system/libraries/Ftp.php b/system/libraries/Ftp.php
index 2d345c294..86e5b8f33 100644
--- a/system/libraries/Ftp.php
+++ b/system/libraries/Ftp.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Libraries
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/ftp.html
+ * @link		https://codeigniter.com/user_guide/libraries/ftp.html
  */
 class CI_FTP {
 
@@ -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/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index e813efd89..8b5a1adb0 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Image_lib
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/image_lib.html
+ * @link		https://codeigniter.com/user_guide/libraries/image_lib.html
  */
 class CI_Image_lib {
 
@@ -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)
-			{
-				$full_dest_path = str_replace('\\', '/', realpath($this->new_image));
-			}
-			else
-			{
-				$full_dest_path = $this->new_image;
-			}
-
 			// Is there a file name?
-			if ( ! preg_match('#\.(jpg|jpeg|gif|png)$#i', $full_dest_path))
+			if ( ! preg_match('#\.(jpg|jpeg|gif|png)$#i', $this->new_image))
 			{
-				$this->dest_folder = $full_dest_path.'/';
-				$this->dest_image = $this->source_image;
+				$this->dest_image  = $this->source_image;
+				$this->dest_folder = $this->new_image;
 			}
 			else
 			{
-				$x = explode('/', $full_dest_path);
-				$this->dest_image = end($x);
-				$this->dest_folder = str_replace($this->dest_image, '', $full_dest_path);
+				$x = explode('/', str_replace('\\', '/', $this->new_image));
+				$this->dest_image  = end($x);
+				$this->dest_folder = str_replace($this->dest_image, '', $this->new_image);
 			}
+
+			$this->dest_folder = realpath($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'))
@@ -1196,7 +1204,7 @@ class CI_Image_lib {
 		}
 
 		// Build the finalized image
-		if ($wm_img_type === 3 && function_exists('imagealphablending'))
+		if ($wm_img_type === 3)
 		{
 			@imagealphablending($src_img, TRUE);
 		}
@@ -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
-				);
-		}
-
-		$this->orig_width	= $vals[0];
-		$this->orig_height	= $vals[1];
-		$this->image_type	= $vals[2];
-		$this->size_str		= $vals[3];
-		$this->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;
 
 		return TRUE;
 	}
diff --git a/system/libraries/Javascript.php b/system/libraries/Javascript.php
deleted file mode 100644
index 4cc628692..000000000
--- a/system/libraries/Javascript.php
+++ /dev/null
@@ -1,856 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, 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
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 1.0.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * Javascript Class
- *
- * @package		CodeIgniter
- * @subpackage	Libraries
- * @category	Javascript
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/javascript.html
- * @deprecated	3.0.0	This was never a good idea in the first place.
- */
-class CI_Javascript {
-
-	/**
-	 * JavaScript location
-	 *
-	 * @var	string
-	 */
-	protected $_javascript_location = 'js';
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Constructor
-	 *
-	 * @param	array	$params
-	 * @return	void
-	 */
-	public function __construct($params = array())
-	{
-		$defaults = array('js_library_driver' => 'jquery', 'autoload' => TRUE);
-
-		foreach ($defaults as $key => $val)
-		{
-			if (isset($params[$key]) && $params[$key] !== '')
-			{
-				$defaults[$key] = $params[$key];
-			}
-		}
-
-		extract($defaults);
-
-		$this->CI =& get_instance();
-
-		// load the requested js library
-		$this->CI->load->library('Javascript/'.$js_library_driver, array('autoload' => $autoload));
-		// make js to refer to current library
-		$this->js =& $this->CI->$js_library_driver;
-
-		log_message('info', 'Javascript Class Initialized and loaded. Driver used: '.$js_library_driver);
-	}
-
-	// --------------------------------------------------------------------
-	// Event Code
-	// --------------------------------------------------------------------
-
-	/**
-	 * Blur
-	 *
-	 * Outputs a javascript library blur event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function blur($element = 'this', $js = '')
-	{
-		return $this->js->_blur($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Change
-	 *
-	 * Outputs a javascript library change event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function change($element = 'this', $js = '')
-	{
-		return $this->js->_change($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Click
-	 *
-	 * Outputs a javascript library click event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @param	bool	whether or not to return false
-	 * @return	string
-	 */
-	public function click($element = 'this', $js = '', $ret_false = TRUE)
-	{
-		return $this->js->_click($element, $js, $ret_false);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Double Click
-	 *
-	 * Outputs a javascript library dblclick event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function dblclick($element = 'this', $js = '')
-	{
-		return $this->js->_dblclick($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Error
-	 *
-	 * Outputs a javascript library error event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function error($element = 'this', $js = '')
-	{
-		return $this->js->_error($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Focus
-	 *
-	 * Outputs a javascript library focus event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function focus($element = 'this', $js = '')
-	{
-		return $this->js->_focus($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Hover
-	 *
-	 * Outputs a javascript library hover event
-	 *
-	 * @param	string	- element
-	 * @param	string	- Javascript code for mouse over
-	 * @param	string	- Javascript code for mouse out
-	 * @return	string
-	 */
-	public function hover($element = 'this', $over = '', $out = '')
-	{
-		return $this->js->_hover($element, $over, $out);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Keydown
-	 *
-	 * Outputs a javascript library keydown event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function keydown($element = 'this', $js = '')
-	{
-		return $this->js->_keydown($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Keyup
-	 *
-	 * Outputs a javascript library keydown event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function keyup($element = 'this', $js = '')
-	{
-		return $this->js->_keyup($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Load
-	 *
-	 * Outputs a javascript library load event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function load($element = 'this', $js = '')
-	{
-		return $this->js->_load($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mousedown
-	 *
-	 * Outputs a javascript library mousedown event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function mousedown($element = 'this', $js = '')
-	{
-		return $this->js->_mousedown($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mouse Out
-	 *
-	 * Outputs a javascript library mouseout event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function mouseout($element = 'this', $js = '')
-	{
-		return $this->js->_mouseout($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mouse Over
-	 *
-	 * Outputs a javascript library mouseover event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function mouseover($element = 'this', $js = '')
-	{
-		return $this->js->_mouseover($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mouseup
-	 *
-	 * Outputs a javascript library mouseup event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function mouseup($element = 'this', $js = '')
-	{
-		return $this->js->_mouseup($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Output
-	 *
-	 * Outputs the called javascript to the screen
-	 *
-	 * @param	string	The code to output
-	 * @return	string
-	 */
-	public function output($js)
-	{
-		return $this->js->_output($js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Ready
-	 *
-	 * Outputs a javascript library mouseup event
-	 *
-	 * @param	string	$js	Code to execute
-	 * @return	string
-	 */
-	public function ready($js)
-	{
-		return $this->js->_document_ready($js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Resize
-	 *
-	 * Outputs a javascript library resize event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function resize($element = 'this', $js = '')
-	{
-		return $this->js->_resize($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Scroll
-	 *
-	 * Outputs a javascript library scroll event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function scroll($element = 'this', $js = '')
-	{
-		return $this->js->_scroll($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Unload
-	 *
-	 * Outputs a javascript library unload event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	public function unload($element = 'this', $js = '')
-	{
-		return $this->js->_unload($element, $js);
-	}
-
-	// --------------------------------------------------------------------
-	// Effects
-	// --------------------------------------------------------------------
-
-	/**
-	 * Add Class
-	 *
-	 * Outputs a javascript library addClass event
-	 *
-	 * @param	string	- element
-	 * @param	string	- Class to add
-	 * @return	string
-	 */
-	public function addClass($element = 'this', $class = '')
-	{
-		return $this->js->_addClass($element, $class);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Animate
-	 *
-	 * Outputs a javascript library animate event
-	 *
-	 * @param	string	$element = 'this'
-	 * @param	array	$params = array()
-	 * @param	mixed	$speed			'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	$extra
-	 * @return	string
-	 */
-	public function animate($element = 'this', $params = array(), $speed = '', $extra = '')
-	{
-		return $this->js->_animate($element, $params, $speed, $extra);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fade In
-	 *
-	 * Outputs a javascript library hide event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function fadeIn($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_fadeIn($element, $speed, $callback);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fade Out
-	 *
-	 * Outputs a javascript library hide event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function fadeOut($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_fadeOut($element, $speed, $callback);
-	}
-	// --------------------------------------------------------------------
-
-	/**
-	 * Slide Up
-	 *
-	 * Outputs a javascript library slideUp event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function slideUp($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_slideUp($element, $speed, $callback);
-
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Remove Class
-	 *
-	 * Outputs a javascript library removeClass event
-	 *
-	 * @param	string	- element
-	 * @param	string	- Class to add
-	 * @return	string
-	 */
-	public function removeClass($element = 'this', $class = '')
-	{
-		return $this->js->_removeClass($element, $class);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Slide Down
-	 *
-	 * Outputs a javascript library slideDown event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function slideDown($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_slideDown($element, $speed, $callback);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Slide Toggle
-	 *
-	 * Outputs a javascript library slideToggle event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function slideToggle($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_slideToggle($element, $speed, $callback);
-
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Hide
-	 *
-	 * Outputs a javascript library hide action
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function hide($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_hide($element, $speed, $callback);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Toggle
-	 *
-	 * Outputs a javascript library toggle event
-	 *
-	 * @param	string	- element
-	 * @return	string
-	 */
-	public function toggle($element = 'this')
-	{
-		return $this->js->_toggle($element);
-
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Toggle Class
-	 *
-	 * Outputs a javascript library toggle class event
-	 *
-	 * @param	string	$element = 'this'
-	 * @param	string	$class = ''
-	 * @return	string
-	 */
-	public function toggleClass($element = 'this', $class = '')
-	{
-		return $this->js->_toggleClass($element, $class);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Show
-	 *
-	 * Outputs a javascript library show event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function show($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_show($element, $speed, $callback);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Compile
-	 *
-	 * gather together all script needing to be output
-	 *
-	 * @param	string	$view_var
-	 * @param	bool	$script_tags
-	 * @return	string
-	 */
-	public function compile($view_var = 'script_foot', $script_tags = TRUE)
-	{
-		$this->js->_compile($view_var, $script_tags);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Clear Compile
-	 *
-	 * Clears any previous javascript collected for output
-	 *
-	 * @return	void
-	 */
-	public function clear_compile()
-	{
-		$this->js->_clear_compile();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * External
-	 *
-	 * Outputs a <script> tag with the source as an external js file
-	 *
-	 * @param	string	$external_file
-	 * @param	bool	$relative
-	 * @return	string
-	 */
-	public function external($external_file = '', $relative = FALSE)
-	{
-		if ($external_file !== '')
-		{
-			$this->_javascript_location = $external_file;
-		}
-		elseif ($this->CI->config->item('javascript_location') !== '')
-		{
-			$this->_javascript_location = $this->CI->config->item('javascript_location');
-		}
-
-		if ($relative === TRUE OR strpos($external_file, 'http://') === 0 OR strpos($external_file, 'https://') === 0)
-		{
-			$str = $this->_open_script($external_file);
-		}
-		elseif (strpos($this->_javascript_location, 'http://') !== FALSE)
-		{
-			$str = $this->_open_script($this->_javascript_location.$external_file);
-		}
-		else
-		{
-			$str = $this->_open_script($this->CI->config->slash_item('base_url').$this->_javascript_location.$external_file);
-		}
-
-		return $str.$this->_close_script();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Inline
-	 *
-	 * Outputs a <script> tag
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	bool	If a CDATA section should be added
-	 * @return	string
-	 */
-	public function inline($script, $cdata = TRUE)
-	{
-		return $this->_open_script()
-			. ($cdata ? "\n// <![CDATA[\n".$script."\n// ]]>\n" : "\n".$script."\n")
-			. $this->_close_script();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Open Script
-	 *
-	 * Outputs an opening <script>
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	protected function _open_script($src = '')
-	{
-		return '<script type="text/javascript" charset="'.strtolower($this->CI->config->item('charset')).'"'
-			.($src === '' ? '>' : ' src="'.$src.'">');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Close Script
-	 *
-	 * Outputs an closing </script>
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	protected function _close_script($extra = "\n")
-	{
-		return '</script>'.$extra;
-	}
-
-	// --------------------------------------------------------------------
-	// AJAX-Y STUFF - still a testbed
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update
-	 *
-	 * Outputs a javascript library slideDown event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	public function update($element = 'this', $speed = '', $callback = '')
-	{
-		return $this->js->_updater($element, $speed, $callback);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Generate JSON
-	 *
-	 * Can be passed a database result or associative array and returns a JSON formatted string
-	 *
-	 * @param	mixed	result set or array
-	 * @param	bool	match array types (defaults to objects)
-	 * @return	string	a json formatted string
-	 */
-	public function generate_json($result = NULL, $match_array_type = FALSE)
-	{
-		// JSON data can optionally be passed to this function
-		// either as a database result object or an array, or a user supplied array
-		if ($result !== NULL)
-		{
-			if (is_object($result))
-			{
-				$json_result = is_callable(array($result, 'result_array')) ? $result->result_array() : (array) $result;
-			}
-			elseif (is_array($result))
-			{
-				$json_result = $result;
-			}
-			else
-			{
-				return $this->_prep_args($result);
-			}
-		}
-		else
-		{
-			return 'null';
-		}
-
-		$json = array();
-		$_is_assoc = TRUE;
-
-		if ( ! is_array($json_result) && empty($json_result))
-		{
-			show_error('Generate JSON Failed - Illegal key, value pair.');
-		}
-		elseif ($match_array_type)
-		{
-			$_is_assoc = $this->_is_associative_array($json_result);
-		}
-
-		foreach ($json_result as $k => $v)
-		{
-			if ($_is_assoc)
-			{
-				$json[] = $this->_prep_args($k, TRUE).':'.$this->generate_json($v, $match_array_type);
-			}
-			else
-			{
-				$json[] = $this->generate_json($v, $match_array_type);
-			}
-		}
-
-		$json = implode(',', $json);
-
-		return $_is_assoc ? '{'.$json.'}' : '['.$json.']';
-
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Is associative array
-	 *
-	 * Checks for an associative array
-	 *
-	 * @param	array
-	 * @return	bool
-	 */
-	protected function _is_associative_array($arr)
-	{
-		foreach (array_keys($arr) as $key => $val)
-		{
-			if ($key !== $val)
-			{
-				return TRUE;
-			}
-		}
-
-		return FALSE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Prep Args
-	 *
-	 * Ensures a standard json value and escapes values
-	 *
-	 * @param	mixed	$result
-	 * @param	bool	$is_key = FALSE
-	 * @return	string
-	 */
-	protected function _prep_args($result, $is_key = FALSE)
-	{
-		if ($result === NULL)
-		{
-			return 'null';
-		}
-		elseif (is_bool($result))
-		{
-			return ($result === TRUE) ? 'true' : 'false';
-		}
-		elseif (is_string($result) OR $is_key)
-		{
-			return '"'.str_replace(array('\\', "\t", "\n", "\r", '"', '/'), array('\\\\', '\\t', '\\n', "\\r", '\"', '\/'), $result).'"';
-		}
-		elseif (is_scalar($result))
-		{
-			return $result;
-		}
-	}
-
-}
diff --git a/system/libraries/Javascript/Jquery.php b/system/libraries/Javascript/Jquery.php
deleted file mode 100644
index 11f2d2361..000000000
--- a/system/libraries/Javascript/Jquery.php
+++ /dev/null
@@ -1,1076 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, 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
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 1.0.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * Jquery Class
- *
- * @package		CodeIgniter
- * @subpackage	Libraries
- * @category	Loader
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/javascript.html
- */
-class CI_Jquery extends CI_Javascript {
-
-	/**
-	 * JavaScript directory location
-	 *
-	 * @var	string
-	 */
-	protected $_javascript_folder = 'js';
-
-	/**
-	 * JQuery code for load
-	 *
-	 * @var	array
-	 */
-	public $jquery_code_for_load = array();
-
-	/**
-	 * JQuery code for compile
-	 *
-	 * @var	array
-	 */
-	public $jquery_code_for_compile = array();
-
-	/**
-	 * JQuery corner active flag
-	 *
-	 * @var	bool
-	 */
-	public $jquery_corner_active = FALSE;
-
-	/**
-	 * JQuery table sorter active flag
-	 *
-	 * @var	bool
-	 */
-	public $jquery_table_sorter_active = FALSE;
-
-	/**
-	 * JQuery table sorter pager active
-	 *
-	 * @var	bool
-	 */
-	public $jquery_table_sorter_pager_active = FALSE;
-
-	/**
-	 * JQuery AJAX image
-	 *
-	 * @var	string
-	 */
-	public $jquery_ajax_img = '';
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Constructor
-	 *
-	 * @param	array	$params
-	 * @return	void
-	 */
-	public function __construct($params)
-	{
-		$this->CI =& get_instance();
-		extract($params);
-
-		if ($autoload === TRUE)
-		{
-			$this->script();
-		}
-
-		log_message('info', 'Jquery Class Initialized');
-	}
-
-	// --------------------------------------------------------------------
-	// Event Code
-	// --------------------------------------------------------------------
-
-	/**
-	 * Blur
-	 *
-	 * Outputs a jQuery blur event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _blur($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'blur');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Change
-	 *
-	 * Outputs a jQuery change event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _change($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'change');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Click
-	 *
-	 * Outputs a jQuery click event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @param	bool	whether or not to return false
-	 * @return	string
-	 */
-	protected function _click($element = 'this', $js = '', $ret_false = TRUE)
-	{
-		is_array($js) OR $js = array($js);
-
-		if ($ret_false)
-		{
-			$js[] = 'return false;';
-		}
-
-		return $this->_add_event($element, $js, 'click');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Double Click
-	 *
-	 * Outputs a jQuery dblclick event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _dblclick($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'dblclick');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Error
-	 *
-	 * Outputs a jQuery error event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _error($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'error');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Focus
-	 *
-	 * Outputs a jQuery focus event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _focus($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'focus');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Hover
-	 *
-	 * Outputs a jQuery hover event
-	 *
-	 * @param	string	- element
-	 * @param	string	- Javascript code for mouse over
-	 * @param	string	- Javascript code for mouse out
-	 * @return	string
-	 */
-	protected function _hover($element = 'this', $over = '', $out = '')
-	{
-		$event = "\n\t$(".$this->_prep_element($element).").hover(\n\t\tfunction()\n\t\t{\n\t\t\t{$over}\n\t\t}, \n\t\tfunction()\n\t\t{\n\t\t\t{$out}\n\t\t});\n";
-
-		$this->jquery_code_for_compile[] = $event;
-
-		return $event;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Keydown
-	 *
-	 * Outputs a jQuery keydown event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _keydown($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'keydown');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Keyup
-	 *
-	 * Outputs a jQuery keydown event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _keyup($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'keyup');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Load
-	 *
-	 * Outputs a jQuery load event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _load($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'load');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mousedown
-	 *
-	 * Outputs a jQuery mousedown event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _mousedown($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'mousedown');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mouse Out
-	 *
-	 * Outputs a jQuery mouseout event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _mouseout($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'mouseout');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mouse Over
-	 *
-	 * Outputs a jQuery mouseover event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _mouseover($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'mouseover');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Mouseup
-	 *
-	 * Outputs a jQuery mouseup event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _mouseup($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'mouseup');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Output
-	 *
-	 * Outputs script directly
-	 *
-	 * @param	array	$array_js = array()
-	 * @return	void
-	 */
-	protected function _output($array_js = array())
-	{
-		if ( ! is_array($array_js))
-		{
-			$array_js = array($array_js);
-		}
-
-		foreach ($array_js as $js)
-		{
-			$this->jquery_code_for_compile[] = "\t".$js."\n";
-		}
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Resize
-	 *
-	 * Outputs a jQuery resize event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _resize($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'resize');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Scroll
-	 *
-	 * Outputs a jQuery scroll event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _scroll($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'scroll');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Unload
-	 *
-	 * Outputs a jQuery unload event
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
-	 */
-	protected function _unload($element = 'this', $js = '')
-	{
-		return $this->_add_event($element, $js, 'unload');
-	}
-
-	// --------------------------------------------------------------------
-	// Effects
-	// --------------------------------------------------------------------
-
-	/**
-	 * Add Class
-	 *
-	 * Outputs a jQuery addClass event
-	 *
-	 * @param	string	$element
-	 * @param	string	$class
-	 * @return	string
-	 */
-	protected function _addClass($element = 'this', $class = '')
-	{
-		$element = $this->_prep_element($element);
-		return '$('.$element.').addClass("'.$class.'");';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Animate
-	 *
-	 * Outputs a jQuery animate event
-	 *
-	 * @param	string	$element
-	 * @param	array	$params
-	 * @param	string	$speed	'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	$extra
-	 * @return	string
-	 */
-	protected function _animate($element = 'this', $params = array(), $speed = '', $extra = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		$animations = "\t\t\t";
-
-		foreach ($params as $param => $value)
-		{
-			$animations .= $param.": '".$value."', ";
-		}
-
-		$animations = substr($animations, 0, -2); // remove the last ", "
-
-		if ($speed !== '')
-		{
-			$speed = ', '.$speed;
-		}
-
-		if ($extra !== '')
-		{
-			$extra = ', '.$extra;
-		}
-
-		return "$({$element}).animate({\n$animations\n\t\t}".$speed.$extra.');';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fade In
-	 *
-	 * Outputs a jQuery hide event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	protected function _fadeIn($element = 'this', $speed = '', $callback = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		if ($callback !== '')
-		{
-			$callback = ", function(){\n{$callback}\n}";
-		}
-
-		return "$({$element}).fadeIn({$speed}{$callback});";
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fade Out
-	 *
-	 * Outputs a jQuery hide event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	protected function _fadeOut($element = 'this', $speed = '', $callback = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		if ($callback !== '')
-		{
-			$callback = ", function(){\n{$callback}\n}";
-		}
-
-		return '$('.$element.').fadeOut('.$speed.$callback.');';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Hide
-	 *
-	 * Outputs a jQuery hide action
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	protected function _hide($element = 'this', $speed = '', $callback = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		if ($callback !== '')
-		{
-			$callback = ", function(){\n{$callback}\n}";
-		}
-
-		return "$({$element}).hide({$speed}{$callback});";
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Remove Class
-	 *
-	 * Outputs a jQuery remove class event
-	 *
-	 * @param	string	$element
-	 * @param	string	$class
-	 * @return	string
-	 */
-	protected function _removeClass($element = 'this', $class = '')
-	{
-		$element = $this->_prep_element($element);
-		return '$('.$element.').removeClass("'.$class.'");';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Slide Up
-	 *
-	 * Outputs a jQuery slideUp event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	protected function _slideUp($element = 'this', $speed = '', $callback = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		if ($callback !== '')
-		{
-			$callback = ", function(){\n{$callback}\n}";
-		}
-
-		return '$('.$element.').slideUp('.$speed.$callback.');';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Slide Down
-	 *
-	 * Outputs a jQuery slideDown event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	protected function _slideDown($element = 'this', $speed = '', $callback = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		if ($callback !== '')
-		{
-			$callback = ", function(){\n{$callback}\n}";
-		}
-
-		return '$('.$element.').slideDown('.$speed.$callback.');';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Slide Toggle
-	 *
-	 * Outputs a jQuery slideToggle event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	protected function _slideToggle($element = 'this', $speed = '', $callback = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		if ($callback !== '')
-		{
-			$callback = ", function(){\n{$callback}\n}";
-		}
-
-		return '$('.$element.').slideToggle('.$speed.$callback.');';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Toggle
-	 *
-	 * Outputs a jQuery toggle event
-	 *
-	 * @param	string	- element
-	 * @return	string
-	 */
-	protected function _toggle($element = 'this')
-	{
-		$element = $this->_prep_element($element);
-		return '$('.$element.').toggle();';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Toggle Class
-	 *
-	 * Outputs a jQuery toggle class event
-	 *
-	 * @param	string	$element
-	 * @param	string	$class
-	 * @return	string
-	 */
-	protected function _toggleClass($element = 'this', $class = '')
-	{
-		$element = $this->_prep_element($element);
-		return '$('.$element.').toggleClass("'.$class.'");';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Show
-	 *
-	 * Outputs a jQuery show event
-	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
-	 * @return	string
-	 */
-	protected function _show($element = 'this', $speed = '', $callback = '')
-	{
-		$element = $this->_prep_element($element);
-		$speed = $this->_validate_speed($speed);
-
-		if ($callback !== '')
-		{
-			$callback = ", function(){\n{$callback}\n}";
-		}
-
-		return '$('.$element.').show('.$speed.$callback.');';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Updater
-	 *
-	 * An Ajax call that populates the designated DOM node with
-	 * returned content
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	the controller to run the call against
-	 * @param	string	optional parameters
-	 * @return	string
-	 */
-
-	protected function _updater($container = 'this', $controller = '', $options = '')
-	{
-		$container = $this->_prep_element($container);
-		$controller = (strpos('://', $controller) === FALSE) ? $controller : $this->CI->config->site_url($controller);
-
-		// ajaxStart and ajaxStop are better choices here... but this is a stop gap
-		if ($this->CI->config->item('javascript_ajax_img') === '')
-		{
-			$loading_notifier = 'Loading...';
-		}
-		else
-		{
-			$loading_notifier = '<img src="'.$this->CI->config->slash_item('base_url').$this->CI->config->item('javascript_ajax_img').'" alt="Loading" />';
-		}
-
-		$updater = '$('.$container.").empty();\n" // anything that was in... get it out
-			."\t\t$(".$container.').prepend("'.$loading_notifier."\");\n"; // to replace with an image
-
-		$request_options = '';
-		if ($options !== '')
-		{
-			$request_options .= ', {'
-					.(is_array($options) ? "'".implode("', '", $options)."'" : "'".str_replace(':', "':'", $options)."'")
-					.'}';
-		}
-
-		return $updater."\t\t$($container).load('$controller'$request_options);";
-	}
-
-	// --------------------------------------------------------------------
-	// Pre-written handy stuff
-	// --------------------------------------------------------------------
-
-	/**
-	 * Zebra tables
-	 *
-	 * @param	string	$class
-	 * @param	string	$odd
-	 * @param	string	$hover
-	 * @return	string
-	 */
-	protected function _zebraTables($class = '', $odd = 'odd', $hover = '')
-	{
-		$class = ($class !== '') ? '.'.$class : '';
-		$zebra = "\t\$(\"table{$class} tbody tr:nth-child(even)\").addClass(\"{$odd}\");";
-
-		$this->jquery_code_for_compile[] = $zebra;
-
-		if ($hover !== '')
-		{
-			$hover = $this->hover("table{$class} tbody tr", "$(this).addClass('hover');", "$(this).removeClass('hover');");
-		}
-
-		return $zebra;
-	}
-
-	// --------------------------------------------------------------------
-	// Plugins
-	// --------------------------------------------------------------------
-
-	/**
-	 * Corner Plugin
-	 *
-	 * @link	http://www.malsup.com/jquery/corner/
-	 * @param	string	$element
-	 * @param	string	$corner_style
-	 * @return	string
-	 */
-	public function corner($element = '', $corner_style = '')
-	{
-		// may want to make this configurable down the road
-		$corner_location = '/plugins/jquery.corner.js';
-
-		if ($corner_style !== '')
-		{
-			$corner_style = '"'.$corner_style.'"';
-		}
-
-		return '$('.$this->_prep_element($element).').corner('.$corner_style.');';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Modal window
-	 *
-	 * Load a thickbox modal window
-	 *
-	 * @param	string	$src
-	 * @param	bool	$relative
-	 * @return	void
-	 */
-	public function modal($src, $relative = FALSE)
-	{
-		$this->jquery_code_for_load[] = $this->external($src, $relative);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Effect
-	 *
-	 * Load an Effect library
-	 *
-	 * @param	string	$src
-	 * @param	bool	$relative
-	 * @return	void
-	 */
-	public function effect($src, $relative = FALSE)
-	{
-		$this->jquery_code_for_load[] = $this->external($src, $relative);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Plugin
-	 *
-	 * Load a plugin library
-	 *
-	 * @param	string	$src
-	 * @param	bool	$relative
-	 * @return	void
-	 */
-	public function plugin($src, $relative = FALSE)
-	{
-		$this->jquery_code_for_load[] = $this->external($src, $relative);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * UI
-	 *
-	 * Load a user interface library
-	 *
-	 * @param	string	$src
-	 * @param	bool	$relative
-	 * @return	void
-	 */
-	public function ui($src, $relative = FALSE)
-	{
-		$this->jquery_code_for_load[] = $this->external($src, $relative);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Sortable
-	 *
-	 * Creates a jQuery sortable
-	 *
-	 * @param	string	$element
-	 * @param	array	$options
-	 * @return	string
-	 */
-	public function sortable($element, $options = array())
-	{
-		if (count($options) > 0)
-		{
-			$sort_options = array();
-			foreach ($options as $k=>$v)
-			{
-				$sort_options[] = "\n\t\t".$k.': '.$v;
-			}
-			$sort_options = implode(',', $sort_options);
-		}
-		else
-		{
-			$sort_options = '';
-		}
-
-		return '$('.$this->_prep_element($element).').sortable({'.$sort_options."\n\t});";
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Table Sorter Plugin
-	 *
-	 * @param	string	table name
-	 * @param	string	plugin location
-	 * @return	string
-	 */
-	public function tablesorter($table = '', $options = '')
-	{
-		$this->jquery_code_for_compile[] = "\t$(".$this->_prep_element($table).').tablesorter('.$options.");\n";
-	}
-
-	// --------------------------------------------------------------------
-	// Class functions
-	// --------------------------------------------------------------------
-
-	/**
-	 * Add Event
-	 *
-	 * Constructs the syntax for an event, and adds to into the array for compilation
-	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @param	string	The event to pass
-	 * @return	string
-	 */
-	protected function _add_event($element, $js, $event)
-	{
-		if (is_array($js))
-		{
-			$js = implode("\n\t\t", $js);
-		}
-
-		$event = "\n\t$(".$this->_prep_element($element).').'.$event."(function(){\n\t\t{$js}\n\t});\n";
-		$this->jquery_code_for_compile[] = $event;
-		return $event;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Compile
-	 *
-	 * As events are specified, they are stored in an array
-	 * This function compiles them all for output on a page
-	 *
-	 * @param	string	$view_var
-	 * @param	bool	$script_tags
-	 * @return	void
-	 */
-	protected function _compile($view_var = 'script_foot', $script_tags = TRUE)
-	{
-		// External references
-		$external_scripts = implode('', $this->jquery_code_for_load);
-		$this->CI->load->vars(array('library_src' => $external_scripts));
-
-		if (count($this->jquery_code_for_compile) === 0)
-		{
-			// no inline references, let's just return
-			return;
-		}
-
-		// Inline references
-		$script = '$(document).ready(function() {'."\n"
-			.implode('', $this->jquery_code_for_compile)
-			.'});';
-
-		$output = ($script_tags === FALSE) ? $script : $this->inline($script);
-
-		$this->CI->load->vars(array($view_var => $output));
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Clear Compile
-	 *
-	 * Clears the array of script events collected for output
-	 *
-	 * @return	void
-	 */
-	protected function _clear_compile()
-	{
-		$this->jquery_code_for_compile = array();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Document Ready
-	 *
-	 * A wrapper for writing document.ready()
-	 *
-	 * @param	array	$js
-	 * @return	void
-	 */
-	protected function _document_ready($js)
-	{
-		is_array($js) OR $js = array($js);
-
-		foreach ($js as $script)
-		{
-			$this->jquery_code_for_compile[] = $script;
-		}
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Script Tag
-	 *
-	 * Outputs the script tag that loads the jquery.js file into an HTML document
-	 *
-	 * @param	string	$library_src
-	 * @param	bool	$relative
-	 * @return	string
-	 */
-	public function script($library_src = '', $relative = FALSE)
-	{
-		$library_src = $this->external($library_src, $relative);
-		$this->jquery_code_for_load[] = $library_src;
-		return $library_src;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Prep Element
-	 *
-	 * Puts HTML element in quotes for use in jQuery code
-	 * unless the supplied element is the Javascript 'this'
-	 * object, in which case no quotes are added
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	protected function _prep_element($element)
-	{
-		if ($element !== 'this')
-		{
-			$element = '"'.$element.'"';
-		}
-
-		return $element;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Validate Speed
-	 *
-	 * Ensures the speed parameter is valid for jQuery
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	protected function _validate_speed($speed)
-	{
-		if (in_array($speed, array('slow', 'normal', 'fast')))
-		{
-			return '"'.$speed.'"';
-		}
-		elseif (preg_match('/[^0-9]/', $speed))
-		{
-			return '';
-		}
-
-		return $speed;
-	}
-
-}
diff --git a/system/libraries/Javascript/index.html b/system/libraries/Javascript/index.html
deleted file mode 100644
index b702fbc39..000000000
--- a/system/libraries/Javascript/index.html
+++ /dev/null
@@ -1,11 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-	<title>403 Forbidden</title>
-</head>
-<body>
-
-<p>Directory access is forbidden.</p>
-
-</body>
-</html>
diff --git a/system/libraries/Migration.php b/system/libraries/Migration.php
index 45a3cbbce..2a87d9d7c 100644
--- a/system/libraries/Migration.php
+++ b/system/libraries/Migration.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -96,9 +96,9 @@ class CI_Migration {
 	/**
 	 * Migration basename regex
 	 *
-	 * @var bool
+	 * @var string
 	 */
-	protected $_migration_regex = NULL;
+	protected $_migration_regex;
 
 	/**
 	 * Error message
@@ -217,31 +217,66 @@ class CI_Migration {
 
 		if ($target_version > $current_version)
 		{
-			// Moving Up
 			$method = 'up';
 		}
-		else
+		elseif ($target_version < $current_version)
 		{
-			// Moving Down, apply in reverse order
 			$method = 'down';
+			// We need this so that migrations are applied in reverse order
 			krsort($migrations);
 		}
-
-		if (empty($migrations))
+		else
 		{
+			// Well, there's nothing to migrate then ...
 			return TRUE;
 		}
 
-		$previous = FALSE;
-
-		// Validate all available migrations, and run the ones within our target range
+		// Validate all available migrations within our target range.
+		//
+		// Unfortunately, we'll have to use another loop to run them
+		// in order to avoid leaving the procedure in a broken state.
+		//
+		// See https://github.com/bcit-ci/CodeIgniter/issues/4539
+		$pending = array();
 		foreach ($migrations as $number => $file)
 		{
+			// Ignore versions out of our range.
+			//
+			// Because we've previously sorted the $migrations array depending on the direction,
+			// we can safely break the loop once we reach $target_version ...
+			if ($method === 'up')
+			{
+				if ($number <= $current_version)
+				{
+					continue;
+				}
+				elseif ($number > $target_version)
+				{
+					break;
+				}
+			}
+			else
+			{
+				if ($number > $current_version)
+				{
+					continue;
+				}
+				elseif ($number <= $target_version)
+				{
+					break;
+				}
+			}
+
 			// Check for sequence gaps
-			if ($this->_migration_type === 'sequential' && $previous !== FALSE && abs($number - $previous) > 1)
+			if ($this->_migration_type === 'sequential')
 			{
-				$this->_error_string = sprintf($this->lang->line('migration_sequence_gap'), $number);
-				return FALSE;
+				if (isset($previous) && abs($number - $previous) > 1)
+				{
+					$this->_error_string = sprintf($this->lang->line('migration_sequence_gap'), $number);
+					return FALSE;
+				}
+
+				$previous = $number;
 			}
 
 			include_once($file);
@@ -253,27 +288,24 @@ class CI_Migration {
 				$this->_error_string = sprintf($this->lang->line('migration_class_doesnt_exist'), $class);
 				return FALSE;
 			}
+			elseif ( ! is_callable(array($class, $method)))
+			{
+				$this->_error_string = sprintf($this->lang->line('migration_missing_'.$method.'_method'), $class);
+				return FALSE;
+			}
 
-			$previous = $number;
+			$pending[$number] = array($class, $method);
+		}
 
-			// Run migrations that are inside the target range
-			if (
-				($method === 'up'   && $number > $current_version && $number <= $target_version) OR
-				($method === 'down' && $number <= $current_version && $number > $target_version)
-			)
-			{
-				$instance = new $class();
-				if ( ! is_callable(array($instance, $method)))
-				{
-					$this->_error_string = sprintf($this->lang->line('migration_missing_'.$method.'_method'), $class);
-					return FALSE;
-				}
+		// Now just run the necessary migrations
+		foreach ($pending as $number => $migration)
+		{
+			log_message('debug', 'Migrating '.$method.' from version '.$current_version.' to version '.$number);
 
-				log_message('debug', 'Migrating '.$method.' from version '.$current_version.' to version '.$number);
-				call_user_func(array($instance, $method));
-				$current_version = $number;
-				$this->_update_version($current_version);
-			}
+			$migration[0] = new $migration[0];
+			call_user_func($migration);
+			$current_version = $number;
+			$this->_update_version($current_version);
 		}
 
 		// This is necessary when moving down, since the the last migration applied
@@ -285,7 +317,6 @@ class CI_Migration {
 		}
 
 		log_message('debug', 'Finished migrating to '.$current_version);
-
 		return $current_version;
 	}
 
diff --git a/system/libraries/Pagination.php b/system/libraries/Pagination.php
index 5b3aa01f4..f26f8a4ed 100644
--- a/system/libraries/Pagination.php
+++ b/system/libraries/Pagination.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Pagination
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/pagination.html
+ * @link		https://codeigniter.com/user_guide/libraries/pagination.html
  */
 class CI_Pagination {
 
@@ -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
@@ -497,7 +497,7 @@ class CI_Pagination {
 		{
 			$this->cur_page = $this->CI->input->get($this->query_string_segment);
 		}
-		else
+		elseif (empty($this->cur_page))
 		{
 			// Default to the last segment number if one hasn't been defined.
 			if ($this->uri_segment === 0)
@@ -513,6 +513,10 @@ class CI_Pagination {
 				$this->cur_page = str_replace(array($this->prefix, $this->suffix), '', $this->cur_page);
 			}
 		}
+		else
+		{
+			$this->cur_page = (string) $this->cur_page;
+		}
 
 		// If something isn't quite right, back to the default base page.
 		if ( ! ctype_digit($this->cur_page) OR ($this->use_page_numbers && (int) $this->cur_page === 0))
@@ -571,7 +575,7 @@ class CI_Pagination {
 		{
 			$i = ($this->use_page_numbers) ? $uri_page_number - 1 : $uri_page_number - $this->per_page;
 
-			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
+			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, ($this->cur_page - 1));
 
 			if ($i === $base_page)
 			{
@@ -592,11 +596,11 @@ class CI_Pagination {
 		if ($this->display_pages !== FALSE)
 		{
 			// Write the digit links
-			for ($loop = $start -1; $loop <= $end; $loop++)
+			for ($loop = $start - 1; $loop <= $end; $loop++)
 			{
 				$i = ($this->use_page_numbers) ? $loop : ($loop * $this->per_page) - $this->per_page;
 
-				$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
+				$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, $loop);
 
 				if ($i >= $base_page)
 				{
@@ -614,7 +618,7 @@ class CI_Pagination {
 					else
 					{
 						$append = $this->prefix.$i.$this->suffix;
-						$output .= $this->num_tag_open.'<a href="'.$base_url.$append.'"'.$attributes.$this->_attr_rel('start').'>'
+						$output .= $this->num_tag_open.'<a href="'.$base_url.$append.'"'.$attributes.'>'
 							.$loop.'</a>'.$this->num_tag_close;
 					}
 				}
@@ -626,7 +630,7 @@ class CI_Pagination {
 		{
 			$i = ($this->use_page_numbers) ? $this->cur_page + 1 : $this->cur_page * $this->per_page;
 
-			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
+			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, $this->cur_page + 1);
 
 			$output .= $this->next_tag_open.'<a href="'.$base_url.$this->prefix.$i.$this->suffix.'"'.$attributes
 				.$this->_attr_rel('next').'>'.$this->next_link.'</a>'.$this->next_tag_close;
@@ -637,7 +641,7 @@ class CI_Pagination {
 		{
 			$i = ($this->use_page_numbers) ? $num_pages : ($num_pages * $this->per_page) - $this->per_page;
 
-			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
+			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, $num_pages);
 
 			$output .= $this->last_tag_open.'<a href="'.$base_url.$this->prefix.$i.$this->suffix.'"'.$attributes.'>'
 				.$this->last_link.'</a>'.$this->last_tag_close;
diff --git a/system/libraries/Parser.php b/system/libraries/Parser.php
index 57981af95..fdd958b22 100644
--- a/system/libraries/Parser.php
+++ b/system/libraries/Parser.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Parser
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/parser.html
+ * @link		https://codeigniter.com/user_guide/libraries/parser.html
  */
 class CI_Parser {
 
diff --git a/system/libraries/Profiler.php b/system/libraries/Profiler.php
index 1e464d8b0..e9e03cfe0 100644
--- a/system/libraries/Profiler.php
+++ b/system/libraries/Profiler.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -50,7 +50,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Libraries
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/general/profiling.html
+ * @link		https://codeigniter.com/user_guide/general/profiling.html
  */
 class CI_Profiler {
 
@@ -314,12 +314,14 @@ class CI_Profiler {
 
 			foreach ($_GET as $key => $val)
 			{
-				is_int($key) OR $key = "'".$key."'";
+				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'))
+					: htmlspecialchars($val, ENT_QUOTES, config_item('charset'));
 
 				$output .= '<tr><td style="width:50%;color:#000;background-color:#ddd;padding:5px;">&#36;_GET['
 					.$key.']&nbsp;&nbsp; </td><td style="width:50%;padding:5px;color:#cd6e00;font-weight:normal;background-color:#ddd;">'
-					.((is_array($val) OR is_object($val)) ? '<pre>'.htmlspecialchars(stripslashes(print_r($val, TRUE))).'</pre>' : htmlspecialchars(stripslashes($val)))
-					."</td></tr>\n";
+					.$val."</td></tr>\n";
 			}
 
 			$output .= "</table>\n";
@@ -352,36 +354,26 @@ class CI_Profiler {
 
 			foreach ($_POST as $key => $val)
 			{
-				is_int($key) OR $key = "'".$key."'";
+				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'))
+					: htmlspecialchars($val, ENT_QUOTES, config_item('charset'));
 
 				$output .= '<tr><td style="width:50%;padding:5px;color:#000;background-color:#ddd;">&#36;_POST['
-					.$key.']&nbsp;&nbsp; </td><td style="width:50%;padding:5px;color:#009900;font-weight:normal;background-color:#ddd;">';
-
-				if (is_array($val) OR is_object($val))
-				{
-					$output .= '<pre>'.htmlspecialchars(stripslashes(print_r($val, TRUE))).'</pre>';
-				}
-				else
-				{
-					$output .= htmlspecialchars(stripslashes($val));
-				}
-
-				$output .= "</td></tr>\n";
+					.$key.']&nbsp;&nbsp; </td><td style="width:50%;padding:5px;color:#009900;font-weight:normal;background-color:#ddd;">'
+					.$val."</td></tr>\n";
 			}
 
 			foreach ($_FILES as $key => $val)
 			{
-				is_int($key) OR $key = "'".$key."'";
+				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'))
+					: htmlspecialchars($val, ENT_QUOTES, config_item('charset'));
 
 				$output .= '<tr><td style="width:50%;padding:5px;color:#000;background-color:#ddd;">&#36;_FILES['
-					.$key.']&nbsp;&nbsp; </td><td style="width:50%;padding:5px;color:#009900;font-weight:normal;background-color:#ddd;">';
-
-				if (is_array($val) OR is_object($val))
-				{
-					$output .= '<pre>'.htmlspecialchars(stripslashes(print_r($val, TRUE))).'</pre>';
-				}
-
-				$output .= "</td></tr>\n";
+					.$key.']&nbsp;&nbsp; </td><td style="width:50%;padding:5px;color:#009900;font-weight:normal;background-color:#ddd;">'
+					.$val."</td></tr>\n";
 			}
 
 			$output .= "</table>\n";
@@ -465,7 +457,7 @@ class CI_Profiler {
 
 		foreach (array('HTTP_ACCEPT', 'HTTP_USER_AGENT', 'HTTP_CONNECTION', 'SERVER_PORT', 'SERVER_NAME', 'REMOTE_ADDR', 'SERVER_SOFTWARE', 'HTTP_ACCEPT_LANGUAGE', 'SCRIPT_NAME', 'REQUEST_METHOD',' HTTP_HOST', 'REMOTE_HOST', 'CONTENT_TYPE', 'SERVER_PROTOCOL', 'QUERY_STRING', 'HTTP_ACCEPT_ENCODING', 'HTTP_X_FORWARDED_FOR', 'HTTP_DNT') as $header)
 		{
-			$val = isset($_SERVER[$header]) ? $_SERVER[$header] : '';
+			$val = isset($_SERVER[$header]) ? htmlspecialchars($_SERVER[$header], ENT_QUOTES, config_item('charset')) : '';
 			$output .= '<tr><td style="vertical-align:top;width:50%;padding:5px;color:#900;background-color:#ddd;">'
 				.$header.'&nbsp;&nbsp;</td><td style="width:50%;padding:5px;color:#000;background-color:#ddd;">'.$val."</td></tr>\n";
 		}
diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
index 05a470d86..3e4865cd1 100644
--- a/system/libraries/Session/Session.php
+++ b/system/libraries/Session/Session.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 2.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Sessions
  * @author		Andrey Andreev
- * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ * @link		https://codeigniter.com/user_guide/libraries/sessions.html
  */
 class CI_Session {
 
@@ -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';
 		}
 
@@ -98,27 +100,12 @@ class CI_Session {
 
 		// Configuration ...
 		$this->_configure($params);
+		$this->_config['_sid_regexp'] = $this->_sid_regexp;
 
 		$class = new $class($this->_config);
 		if ($class instanceof SessionHandlerInterface)
 		{
-			if (is_php('5.4'))
-			{
-				session_set_save_handler($class, TRUE);
-			}
-			else
-			{
-				session_set_save_handler(
-					array($class, 'open'),
-					array($class, 'close'),
-					array($class, 'read'),
-					array($class, 'write'),
-					array($class, 'destroy'),
-					array($class, 'gc')
-				);
-
-				register_shutdown_function('session_write_close');
-			}
+			session_set_save_handler($class, TRUE);
 		}
 		else
 		{
@@ -130,7 +117,7 @@ class CI_Session {
 		if (isset($_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']])
 			)
 		)
 		{
@@ -187,9 +174,6 @@ class CI_Session {
 	 */
 	protected function _ci_load_classes($driver)
 	{
-		// PHP 5.4 compatibility
-		interface_exists('SessionHandlerInterface', FALSE) OR require_once(BASEPATH.'libraries/Session/SessionHandlerInterface.php');
-
 		$prefix = config_item('subclass_prefix');
 
 		if ( ! class_exists('CI_Session_driver', FALSE))
@@ -231,7 +215,7 @@ class CI_Session {
 			}
 		}
 
-		if ( ! class_exists($prefix.$class) && file_exists($file_path = APPPATH.'libraries/Session/drivers/'.$prefix.$class.'.php'))
+		if ( ! class_exists($prefix.$class, FALSE) && file_exists($file_path = APPPATH.'libraries/Session/drivers/'.$prefix.$class.'.php'))
 		{
 			require_once($file_path);
 			if (class_exists($prefix.$class, FALSE))
@@ -314,8 +298,82 @@ 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.'}';
 	}
 
 	// ------------------------------------------------------------------------
@@ -584,6 +642,24 @@ class CI_Session {
 	// ------------------------------------------------------------------------
 
 	/**
+	 * __isset()
+	 *
+	 * @param	string	$key	'session_id' or a session data key
+	 * @return	bool
+	 */
+	public function __isset($key)
+	{
+		if ($key === 'session_id')
+		{
+			return (session_status() === PHP_SESSION_ACTIVE);
+		}
+
+		return isset($_SESSION[$key]);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
 	 * __set()
 	 *
 	 * @param	string	$key	Session data key
@@ -711,7 +787,7 @@ 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/system/libraries/Session/SessionHandlerInterface.php b/system/libraries/Session/SessionHandlerInterface.php
deleted file mode 100644
index 9dab5ac07..000000000
--- a/system/libraries/Session/SessionHandlerInterface.php
+++ /dev/null
@@ -1,59 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2015, 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
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
- * @since	Version 3.0.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SessionHandlerInterface
- *
- * PHP 5.4 compatibility interface
- *
- * @package	CodeIgniter
- * @subpackage	Libraries
- * @category	Sessions
- * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/libraries/sessions.html
- */
-interface SessionHandlerInterface {
-
-	public function open($save_path, $name);
-	public function close();
-	public function read($session_id);
-	public function write($session_id, $session_data);
-	public function destroy($session_id);
-	public function gc($maxlifetime);
-}
diff --git a/system/libraries/Session/Session_driver.php b/system/libraries/Session/Session_driver.php
index 47376da5b..f32f14ae0 100644
--- a/system/libraries/Session/Session_driver.php
+++ b/system/libraries/Session/Session_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Sessions
  * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/libraries/sessions.html
+ * @link	https://codeigniter.com/user_guide/libraries/sessions.html
  */
 abstract class CI_Session_driver implements SessionHandlerInterface {
 
@@ -74,6 +74,18 @@ abstract class CI_Session_driver implements SessionHandlerInterface {
 	 */
 	protected $_session_id;
 
+	/**
+	 * Success and failure return values
+	 *
+	 * Necessary due to a bug in all PHP 5 versions where return values
+	 * from userspace handlers are not handled properly. PHP 7 fixes the
+	 * bug, so we need to return different values depending on the version.
+	 *
+	 * @see	https://wiki.php.net/rfc/session.user.return-value
+	 * @var	mixed
+	 */
+	protected $_success, $_failure;
+
 	// ------------------------------------------------------------------------
 
 	/**
@@ -85,6 +97,17 @@ abstract class CI_Session_driver implements SessionHandlerInterface {
 	public function __construct(&$params)
 	{
 		$this->_config =& $params;
+
+		if (is_php('7'))
+		{
+			$this->_success = TRUE;
+			$this->_failure = FALSE;
+		}
+		else
+		{
+			$this->_success = 0;
+			$this->_failure = -1;
+		}
 	}
 
 	// ------------------------------------------------------------------------
@@ -145,4 +168,24 @@ abstract class CI_Session_driver implements SessionHandlerInterface {
 		return TRUE;
 	}
 
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fail
+	 *
+	 * Drivers other than the 'files' one don't (need to) use the
+	 * session.save_path INI setting, but that leads to confusing
+	 * error messages emitted by PHP when open() or write() fail,
+	 * as the message contains session.save_path ...
+	 * To work around the problem, the drivers will call this method
+	 * so that the INI is set just in time for the error message to
+	 * be properly generated.
+	 *
+	 * @return	mixed
+	 */
+	protected function _fail()
+	{
+		ini_set('session.save_path', config_item('sess_save_path'));
+		return $this->_failure;
+	}
 }
diff --git a/system/libraries/Session/drivers/Session_database_driver.php b/system/libraries/Session/drivers/Session_database_driver.php
index 1d01c2923..31f5a4663 100644
--- a/system/libraries/Session/drivers/Session_database_driver.php
+++ b/system/libraries/Session/drivers/Session_database_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Sessions
  * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/libraries/sessions.html
+ * @link	https://codeigniter.com/user_guide/libraries/sessions.html
  */
 class CI_Session_database_driver extends CI_Session_driver implements SessionHandlerInterface {
 
@@ -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".');
+		}
 	}
 
 	// ------------------------------------------------------------------------
@@ -125,9 +128,12 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	 */
 	public function open($save_path, $name)
 	{
-		return empty($this->_db->conn_id)
-			? (bool) $this->_db->db_connect()
-			: TRUE;
+		if (empty($this->_db->conn_id) && ! $this->_db->db_connect())
+		{
+			return $this->_fail();
+		}
+
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -144,6 +150,9 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	{
 		if ($this->_get_lock($session_id) !== FALSE)
 		{
+			// Prevent previous QB calls from messing with our queries
+			$this->_db->reset_query();
+
 			// Needed by write() to detect session_regenerate_id() calls
 			$this->_session_id = $session_id;
 
@@ -157,8 +166,12 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 				$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
 			}
 
-			if (($result = $this->_db->get()->row()) === NULL)
+			if ( ! ($result = $this->_db->get()) OR ($result = $result->row()) === NULL)
 			{
+				// PHP7 will reuse the same SessionHandler object after
+				// ID regeneration, so we need to explicitly set this to
+				// FALSE instead of relying on the default ...
+				$this->_row_exists = FALSE;
 				$this->_fingerprint = md5('');
 				return '';
 			}
@@ -192,21 +205,24 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	 */
 	public function write($session_id, $session_data)
 	{
+		// Prevent previous QB calls from messing with our queries
+		$this->_db->reset_query();
+
+		if ($this->_lock === FALSE)
+		{
+			return $this->_fail();
+		}
 		// Was the ID regenerated?
-		if ($session_id !== $this->_session_id)
+		elseif ($session_id !== $this->_session_id)
 		{
 			if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
 			{
-				return FALSE;
+				return $this->_fail();
 			}
 
 			$this->_row_exists = FALSE;
 			$this->_session_id = $session_id;
 		}
-		elseif ($this->_lock === FALSE)
-		{
-			return FALSE;
-		}
 
 		if ($this->_row_exists === FALSE)
 		{
@@ -220,10 +236,11 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 			if ($this->_db->insert($this->_config['save_path'], $insert_data))
 			{
 				$this->_fingerprint = md5($session_data);
-				return $this->_row_exists = TRUE;
+				$this->_row_exists = TRUE;
+				return $this->_success;
 			}
 
-			return FALSE;
+			return $this->_fail();
 		}
 
 		$this->_db->where('id', $session_id);
@@ -243,10 +260,10 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 		if ($this->_db->update($this->_config['save_path'], $update_data))
 		{
 			$this->_fingerprint = md5($session_data);
-			return TRUE;
+			return $this->_success;
 		}
 
-		return FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -260,9 +277,9 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	 */
 	public function close()
 	{
-		return ($this->_lock)
-			? $this->_release_lock()
-			: TRUE;
+		return ($this->_lock && ! $this->_release_lock())
+			? $this->_fail()
+			: $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -279,18 +296,28 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	{
 		if ($this->_lock)
 		{
+			// Prevent previous QB calls from messing with our queries
+			$this->_db->reset_query();
+
 			$this->_db->where('id', $session_id);
 			if ($this->_config['match_ip'])
 			{
 				$this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']);
 			}
 
-			return $this->_db->delete($this->_config['save_path'])
-				? ($this->close() && $this->_cookie_destroy())
-				: FALSE;
+			if ( ! $this->_db->delete($this->_config['save_path']))
+			{
+				return $this->_fail();
+			}
 		}
 
-		return ($this->close() && $this->_cookie_destroy());
+		if ($this->close() === $this->_success)
+		{
+			$this->_cookie_destroy();
+			return $this->_success;
+		}
+
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -305,7 +332,12 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 	 */
 	public function gc($maxlifetime)
 	{
-		return $this->_db->delete($this->_config['save_path'], 'timestamp < '.(time() - $maxlifetime));
+		// Prevent previous QB calls from messing with our queries
+		$this->_db->reset_query();
+
+		return ($this->_db->delete($this->_config['save_path'], 'timestamp < '.(time() - $maxlifetime)))
+			? $this->_success
+			: $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -322,7 +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;
@@ -385,5 +417,4 @@ class CI_Session_database_driver extends CI_Session_driver implements SessionHan
 
 		return parent::_release_lock();
 	}
-
 }
diff --git a/system/libraries/Session/drivers/Session_files_driver.php b/system/libraries/Session/drivers/Session_files_driver.php
index 45da91c46..6016e094e 100644
--- a/system/libraries/Session/drivers/Session_files_driver.php
+++ b/system/libraries/Session/drivers/Session_files_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
 */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Sessions
  * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/libraries/sessions.html
+ * @link	https://codeigniter.com/user_guide/libraries/sessions.html
  */
 class CI_Session_files_driver extends CI_Session_driver implements SessionHandlerInterface {
 
@@ -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_override flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_override;
+
 	// ------------------------------------------------------------------------
 
 	/**
@@ -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_override) OR self::$func_override = (extension_loaded('mbstring') && ini_get('mbstring.func_override'));
 	}
 
 	// ------------------------------------------------------------------------
@@ -129,7 +148,7 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 			.$name // we'll use the session cookie name as a prefix to avoid collisions
 			.($this->_config['match_ip'] ? md5($_SERVER['REMOTE_ADDR']) : '');
 
-		return TRUE;
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -148,21 +167,12 @@ 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.$session_id."' doesn't exist and cannot be created.");
-					return FALSE;
-				}
-			}
-			elseif (($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 FALSE;
+				return $this->_failure;
 			}
 
 			if (flock($this->_file_handle, LOCK_EX) === FALSE)
@@ -170,7 +180,7 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 				log_message('error', "Session: Unable to obtain lock for file '".$this->_file_path.$session_id."'.");
 				fclose($this->_file_handle);
 				$this->_file_handle = NULL;
-				return FALSE;
+				return $this->_failure;
 			}
 
 			// Needed by write() to detect session_regenerate_id() calls
@@ -183,13 +193,19 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 				return '';
 			}
 		}
+		// We shouldn't need this, but apparently we do ...
+		// See https://github.com/bcit-ci/CodeIgniter/issues/4039
+		elseif ($this->_file_handle === FALSE)
+		{
+			return $this->_failure;
+		}
 		else
 		{
 			rewind($this->_file_handle);
 		}
 
 		$session_data = '';
-		for ($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 - $read)) === FALSE)
 			{
@@ -218,20 +234,20 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 	{
 		// If the two IDs don't match, we have a session_regenerate_id() call
 		// and we need to close the old handle and open a new one
-		if ($session_id !== $this->_session_id && ( ! $this->close() OR $this->read($session_id) === FALSE))
+		if ($session_id !== $this->_session_id && ($this->close() === $this->_failure OR $this->read($session_id) === $this->_failure))
 		{
-			return FALSE;
+			return $this->_failure;
 		}
 
 		if ( ! is_resource($this->_file_handle))
 		{
-			return FALSE;
+			return $this->_failure;
 		}
 		elseif ($this->_fingerprint === md5($session_data))
 		{
-			return ($this->_file_new)
-				? TRUE
-				: touch($this->_file_path.$session_id);
+			return ( ! $this->_file_new && ! touch($this->_file_path.$session_id))
+				? $this->_failure
+				: $this->_success;
 		}
 
 		if ( ! $this->_file_new)
@@ -254,12 +270,12 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 			{
 				$this->_fingerprint = md5(substr($session_data, 0, $written));
 				log_message('error', 'Session: Unable to write data.');
-				return FALSE;
+				return $this->_failure;
 			}
 		}
 
 		$this->_fingerprint = md5($session_data);
-		return TRUE;
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -279,10 +295,9 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 			fclose($this->_file_handle);
 
 			$this->_file_handle = $this->_file_new = $this->_session_id = NULL;
-			return TRUE;
 		}
 
-		return TRUE;
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -297,21 +312,33 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 	 */
 	public function destroy($session_id)
 	{
-		if ($this->close())
+		if ($this->close() === $this->_success)
 		{
-			return file_exists($this->_file_path.$session_id)
-				? (unlink($this->_file_path.$session_id) && $this->_cookie_destroy())
-				: TRUE;
+			if (file_exists($this->_file_path.$session_id))
+			{
+				$this->_cookie_destroy();
+				return unlink($this->_file_path.$session_id)
+					? $this->_success
+					: $this->_failure;
+			}
+
+			return $this->_success;
 		}
 		elseif ($this->_file_path !== NULL)
 		{
 			clearstatcache();
-			return file_exists($this->_file_path.$session_id)
-				? (unlink($this->_file_path.$session_id) && $this->_cookie_destroy())
-				: TRUE;
+			if (file_exists($this->_file_path.$session_id))
+			{
+				$this->_cookie_destroy();
+				return unlink($this->_file_path.$session_id)
+					? $this->_success
+					: $this->_failure;
+			}
+
+			return $this->_success;
 		}
 
-		return FALSE;
+		return $this->_failure;
 	}
 
 	// ------------------------------------------------------------------------
@@ -329,15 +356,18 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 		if ( ! is_dir($this->_config['save_path']) OR ($directory = opendir($this->_config['save_path'])) === FALSE)
 		{
 			log_message('debug', "Session: Garbage collector couldn't list files under directory '".$this->_config['save_path']."'.");
-			return FALSE;
+			return $this->_failure;
 		}
 
 		$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)
@@ -356,7 +386,21 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 
 		closedir($directory);
 
-		return TRUE;
+		return $this->_success;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return (self::$func_override)
+			? mb_strlen($str, '8bit')
+			: strlen($str);
+	}
 }
diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index 97b860588..2556bf0f7 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Sessions
  * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/libraries/sessions.html
+ * @link	https://codeigniter.com/user_guide/libraries/sessions.html
  */
 class CI_Session_memcached_driver extends CI_Session_driver implements SessionHandlerInterface {
 
@@ -117,7 +117,7 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 		{
 			$this->_memcached = NULL;
 			log_message('error', 'Session: Invalid Memcached save path format: '.$this->_config['save_path']);
-			return FALSE;
+			return $this->_fail();
 		}
 
 		foreach ($matches as $match)
@@ -142,10 +142,10 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 		if (empty($server_list))
 		{
 			log_message('error', 'Session: Memcached server pool is empty.');
-			return FALSE;
+			return $this->_fail();
 		}
 
-		return TRUE;
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -170,7 +170,7 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 			return $session_data;
 		}
 
-		return FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -186,40 +186,44 @@ 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 FALSE;
+			return $this->_fail();
 		}
 		// Was the ID regenerated?
 		elseif ($session_id !== $this->_session_id)
 		{
 			if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
 			{
-				return FALSE;
+				return $this->_fail();
 			}
 
 			$this->_fingerprint = md5('');
 			$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)))
 		{
-			$this->_memcached->replace($this->_lock_key, time(), 300);
-			if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
+			if ($this->_memcached->set($key, $session_data, $this->_config['expiration']))
 			{
-				if ($this->_memcached->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration']))
-				{
-					$this->_fingerprint = $fingerprint;
-					return TRUE;
-				}
-
-				return FALSE;
+				$this->_fingerprint = $fingerprint;
+				return $this->_success;
 			}
 
-			return $this->_memcached->touch($this->_key_prefix.$session_id, $this->_config['expiration']);
+			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 FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -235,17 +239,17 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 	{
 		if (isset($this->_memcached))
 		{
-			isset($this->_lock_key) && $this->_memcached->delete($this->_lock_key);
+			$this->_release_lock();
 			if ( ! $this->_memcached->quit())
 			{
-				return FALSE;
+				return $this->_fail();
 			}
 
 			$this->_memcached = NULL;
-			return TRUE;
+			return $this->_success;
 		}
 
-		return FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -263,10 +267,11 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 		if (isset($this->_memcached, $this->_lock_key))
 		{
 			$this->_memcached->delete($this->_key_prefix.$session_id);
-			return $this->_cookie_destroy();
+			$this->_cookie_destroy();
+			return $this->_success;
 		}
 
-		return FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -282,7 +287,7 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 	public function gc($maxlifetime)
 	{
 		// Not necessary, Memcached takes care of that.
-		return TRUE;
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -297,9 +302,17 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 	 */
 	protected function _get_lock($session_id)
 	{
-		if (isset($this->_lock_key))
+		// PHP 7 reuses the SessionHandler object on regeneration,
+		// so we need to check here if the lock key is for the
+		// correct session ID.
+		if ($this->_lock_key === $this->_key_prefix.$session_id.':lock')
 		{
-			return $this->_memcached->replace($this->_lock_key, time(), 300);
+			if ( ! $this->_memcached->replace($this->_lock_key, time(), 300))
+			{
+				return ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND)
+					? $this->_memcached->set($this->_lock_key, time(), 300)
+					: FALSE;
+			}
 		}
 
 		// 30 attempts to obtain a lock, in case another request already has it
@@ -359,5 +372,4 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 
 		return TRUE;
 	}
-
 }
diff --git a/system/libraries/Session/drivers/Session_redis_driver.php b/system/libraries/Session/drivers/Session_redis_driver.php
index b098cc441..5313de04c 100644
--- a/system/libraries/Session/drivers/Session_redis_driver.php
+++ b/system/libraries/Session/drivers/Session_redis_driver.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 3.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Sessions
  * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/libraries/sessions.html
+ * @link	https://codeigniter.com/user_guide/libraries/sessions.html
  */
 class CI_Session_redis_driver extends CI_Session_driver implements SessionHandlerInterface {
 
@@ -69,6 +69,13 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 	 */
 	protected $_lock_key;
 
+	/**
+	 * Key exists flag
+	 *
+	 * @var bool
+	 */
+	protected $_key_exists = FALSE;
+
 	// ------------------------------------------------------------------------
 
 	/**
@@ -85,27 +92,40 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 		{
 			log_message('error', 'Session: No Redis save path configured.');
 		}
-		elseif (preg_match('#(?:tcp://)?([^:?]+)(?:\:(\d+))?(\?.+)?#', $this->_config['save_path'], $matches))
+		elseif (preg_match('#^unix://([^\?]+)(?<options>\?.+)?$#', $this->_config['save_path'], $matches))
+		{
+			$save_path = array('path' => $matches[1]);
+		}
+		elseif (preg_match('#(?:tcp://)?([^:?]+)(?:\:(\d+))?(?<options>\?.+)?#', $this->_config['save_path'], $matches))
 		{
-			isset($matches[3]) OR $matches[3] = ''; // Just to avoid undefined index notices below
-			$this->_config['save_path'] = array(
-				'host' => $matches[1],
-				'port' => empty($matches[2]) ? NULL : $matches[2],
-				'password' => preg_match('#auth=([^\s&]+)#', $matches[3], $match) ? $match[1] : NULL,
-				'database' => preg_match('#database=(\d+)#', $matches[3], $match) ? (int) $match[1] : NULL,
-				'timeout' => preg_match('#timeout=(\d+\.\d+)#', $matches[3], $match) ? (float) $match[1] : NULL
+			$save_path = array(
+				'host'    => $matches[1],
+				'port'    => empty($matches[2]) ? NULL : $matches[2],
+				'timeout' => NULL // We always pass this to Redis::connect(), so it needs to exist
 			);
-
-			preg_match('#prefix=([^\s&]+)#', $matches[3], $match) && $this->_key_prefix = $match[1];
 		}
 		else
 		{
 			log_message('error', 'Session: Invalid Redis save path format: '.$this->_config['save_path']);
 		}
 
-		if ($this->_config['match_ip'] === TRUE)
+		if (isset($save_path))
 		{
-			$this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':';
+			if (isset($matches['options']))
+			{
+				$save_path['password'] = preg_match('#auth=([^\s&]+)#', $matches['options'], $match) ? $match[1] : NULL;
+				$save_path['database'] = preg_match('#database=(\d+)#', $matches['options'], $match) ? (int) $match[1] : NULL;
+				$save_path['timeout']  = preg_match('#timeout=(\d+\.\d+)#', $matches['options'], $match) ? (float) $match[1] : NULL;
+
+				preg_match('#prefix=([^\s&]+)#', $matches['options'], $match) && $this->_key_prefix = $match[1];
+			}
+
+			$this->_config['save_path'] = $save_path;
+
+			if ($this->_config['match_ip'] === TRUE)
+			{
+				$this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':';
+			}
 		}
 	}
 
@@ -124,29 +144,40 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 	{
 		if (empty($this->_config['save_path']))
 		{
-			return FALSE;
+			return $this->_fail();
 		}
 
 		$redis = new Redis();
-		if ( ! $redis->connect($this->_config['save_path']['host'], $this->_config['save_path']['port'], $this->_config['save_path']['timeout']))
-		{
-			log_message('error', 'Session: Unable to connect to Redis with the configured settings.');
-		}
-		elseif (isset($this->_config['save_path']['password']) && ! $redis->auth($this->_config['save_path']['password']))
-		{
-			log_message('error', 'Session: Unable to authenticate to Redis instance.');
-		}
-		elseif (isset($this->_config['save_path']['database']) && ! $redis->select($this->_config['save_path']['database']))
+		$connected = isset($this->_config['save_path']['path'])
+			? $redis->connect($this->_config['save_path']['path'])
+			: $redis->connect(
+				$this->_config['save_path']['host'],
+				$this->_config['save_path']['port'],
+				$this->_config['save_path']['timeout']
+			);
+
+		if ($connected)
 		{
-			log_message('error', 'Session: Unable to select Redis database with index '.$this->_config['save_path']['database']);
+			if (isset($this->_config['save_path']['password']) && ! $redis->auth($this->_config['save_path']['password']))
+			{
+				log_message('error', 'Session: Unable to authenticate to Redis instance.');
+			}
+			elseif (isset($this->_config['save_path']['database']) && ! $redis->select($this->_config['save_path']['database']))
+			{
+				log_message('error', 'Session: Unable to select Redis database with index '.$this->_config['save_path']['database']);
+			}
+			else
+			{
+				$this->_redis = $redis;
+				return $this->_success;
+			}
 		}
 		else
 		{
-			$this->_redis = $redis;
-			return TRUE;
+			log_message('error', 'Session: Unable to connect to Redis with the configured settings.');
 		}
 
-		return FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -166,12 +197,17 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 			// Needed by write() to detect session_regenerate_id() calls
 			$this->_session_id = $session_id;
 
-			$session_data = (string) $this->_redis->get($this->_key_prefix.$session_id);
+			$session_data = $this->_redis->get($this->_key_prefix.$session_id);
+
+			is_string($session_data)
+				? $this->_key_exists = TRUE
+				: $session_data = '';
+
 			$this->_fingerprint = md5($session_data);
 			return $session_data;
 		}
 
-		return FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -187,40 +223,38 @@ 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 FALSE;
+			return $this->_fail();
 		}
 		// Was the ID regenerated?
 		elseif ($session_id !== $this->_session_id)
 		{
 			if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
 			{
-				return FALSE;
+				return $this->_fail();
 			}
 
-			$this->_fingerprint = md5('');
+			$this->_key_exists = FALSE;
 			$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($session_data)))
+			if ($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;
-					return TRUE;
-				}
-
-				return FALSE;
+				$this->_fingerprint = $fingerprint;
+				$this->_key_exists = TRUE;
+				return $this->_success;
 			}
 
-			return $this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_config['expiration']);
+			return $this->_fail();
 		}
 
-		return FALSE;
+		return ($this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_config['expiration']))
+			? $this->_success
+			: $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -239,10 +273,10 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 			try {
 				if ($this->_redis->ping() === '+PONG')
 				{
-					isset($this->_lock_key) && $this->_redis->delete($this->_lock_key);
-					if ( ! $this->_redis->close())
+					$this->_release_lock();
+					if ($this->_redis->close() === FALSE)
 					{
-						return FALSE;
+						return $this->_fail();
 					}
 				}
 			}
@@ -252,10 +286,10 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 			}
 
 			$this->_redis = NULL;
-			return TRUE;
+			return $this->_success;
 		}
 
-		return TRUE;
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -277,10 +311,11 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 				log_message('debug', 'Session: Redis::delete() expected to return 1, got '.var_export($result, TRUE).' instead.');
 			}
 
-			return $this->_cookie_destroy();
+			$this->_cookie_destroy();
+			return $this->_success;
 		}
 
-		return FALSE;
+		return $this->_fail();
 	}
 
 	// ------------------------------------------------------------------------
@@ -296,7 +331,7 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 	public function gc($maxlifetime)
 	{
 		// Not necessary, Redis takes care of that.
-		return TRUE;
+		return $this->_success;
 	}
 
 	// ------------------------------------------------------------------------
@@ -311,7 +346,10 @@ class CI_Session_redis_driver extends CI_Session_driver implements SessionHandle
 	 */
 	protected function _get_lock($session_id)
 	{
-		if (isset($this->_lock_key))
+		// PHP 7 reuses the SessionHandler object on regeneration,
+		// so we need to check here if the lock key is for the
+		// correct session ID.
+		if ($this->_lock_key === $this->_key_prefix.$session_id.':lock')
 		{
 			return $this->_redis->setTimeout($this->_lock_key, 300);
 		}
diff --git a/system/libraries/Table.php b/system/libraries/Table.php
index 2d9823093..dc309890b 100644
--- a/system/libraries/Table.php
+++ b/system/libraries/Table.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.1
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	HTML Tables
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/table.html
+ * @link		https://codeigniter.com/user_guide/libraries/table.html
  */
 class CI_Table {
 
@@ -277,6 +277,7 @@ class CI_Table {
 	public function set_caption($caption)
 	{
 		$this->caption = $caption;
+		return $this;
 	}
 
 	// --------------------------------------------------------------------
@@ -426,6 +427,7 @@ class CI_Table {
 		$this->rows = array();
 		$this->heading = array();
 		$this->auto_heading = TRUE;
+		$this->caption = NULL;
 		return $this;
 	}
 
diff --git a/system/libraries/Trackback.php b/system/libraries/Trackback.php
index 23bdbbd58..55e9a0ee6 100644
--- a/system/libraries/Trackback.php
+++ b/system/libraries/Trackback.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Trackbacks
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/trackback.html
+ * @link		https://codeigniter.com/user_guide/libraries/trackback.html
  */
 class CI_Trackback {
 
@@ -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/system/libraries/Typography.php b/system/libraries/Typography.php
index 3b6cb1645..b25d8fdaa 100644
--- a/system/libraries/Typography.php
+++ b/system/libraries/Typography.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Helpers
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/typography.html
+ * @link		https://codeigniter.com/user_guide/libraries/typography.html
  */
 class CI_Typography {
 
@@ -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/system/libraries/Unit_test.php b/system/libraries/Unit_test.php
index 3f986f3e8..38e0fbd24 100644
--- a/system/libraries/Unit_test.php
+++ b/system/libraries/Unit_test.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.3.1
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	UnitTesting
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/unit_testing.html
+ * @link		https://codeigniter.com/user_guide/libraries/unit_testing.html
  */
 class CI_Unit_test {
 
@@ -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/system/libraries/Upload.php b/system/libraries/Upload.php
index 8a2dec76a..3a1731e58 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -44,7 +44,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Uploads
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/file_uploading.html
+ * @link		https://codeigniter.com/user_guide/libraries/file_uploading.html
  */
 class CI_Upload {
 
@@ -286,7 +286,7 @@ class CI_Upload {
 	/**
 	 * Constructor
 	 *
-	 * @param	array	$props
+	 * @param	array	$config
 	 * @return	void
 	 */
 	public function __construct($config = array())
@@ -526,6 +526,12 @@ class CI_Upload {
 			$this->file_name = preg_replace('/\s+/', '_', $this->file_name);
 		}
 
+		if ($this->file_ext_tolower && ($ext_length = strlen($this->file_ext)))
+		{
+			// file_ext was previously lower-cased by a get_extension() call
+			$this->file_name = substr($this->file_name, 0, -$ext_length).$this->file_ext;
+		}
+
 		/*
 		 * Validate the file name
 		 * This function appends an number onto the end of
@@ -595,7 +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,
@@ -1077,16 +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
 		}
 
@@ -1201,10 +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'))
 		{
@@ -1239,9 +1259,7 @@ class CI_Upload {
 		 */
 		if (DIRECTORY_SEPARATOR !== '\\')
 		{
-			$cmd = function_exists('escapeshellarg')
-				? 'file --brief --mime '.escapeshellarg($file['tmp_name']).' 2>&1'
-				: 'file --brief --mime '.$file['tmp_name'].' 2>&1';
+			$cmd = 'file --brief --mime '.escapeshellarg($file['tmp_name']).' 2>&1';
 
 			if (function_usable('exec'))
 			{
@@ -1258,7 +1276,7 @@ class CI_Upload {
 				}
 			}
 
-			if ( ! ini_get('safe_mode') && function_usable('shell_exec'))
+			if (function_usable('shell_exec'))
 			{
 				$mime = @shell_exec($cmd);
 				if (strlen($mime) > 0)
diff --git a/system/libraries/User_agent.php b/system/libraries/User_agent.php
index 53d932a53..cda3ef0a0 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -46,7 +46,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	User Agent
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/user_agent.html
+ * @link		https://codeigniter.com/user_guide/libraries/user_agent.html
  */
 class CI_User_agent {
 
@@ -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/system/libraries/Xmlrpc.php b/system/libraries/Xmlrpc.php
index 55555f56f..e025c4508 100644
--- a/system/libraries/Xmlrpc.php
+++ b/system/libraries/Xmlrpc.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -51,7 +51,7 @@ if ( ! function_exists('xml_parser_create'))
  * @subpackage	Libraries
  * @category	XML-RPC
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/xmlrpc.html
+ * @link		https://codeigniter.com/user_guide/libraries/xmlrpc.html
  */
 class CI_Xmlrpc {
 
@@ -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;
 		}
@@ -559,7 +559,7 @@ class CI_Xmlrpc {
  *
  * @category	XML-RPC
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/xmlrpc.html
+ * @link		https://codeigniter.com/user_guide/libraries/xmlrpc.html
  */
 class XML_RPC_Client extends CI_Xmlrpc
 {
@@ -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
 			{
@@ -781,7 +780,7 @@ class XML_RPC_Client extends CI_Xmlrpc
  *
  * @category	XML-RPC
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/xmlrpc.html
+ * @link		https://codeigniter.com/user_guide/libraries/xmlrpc.html
  */
 class XML_RPC_Response
 {
@@ -837,9 +836,7 @@ class XML_RPC_Response
 		{
 			// error
 			$this->errno = $code;
-			$this->errstr = htmlspecialchars($fstr,
-							(is_php('5.4') ? ENT_XML1 | ENT_NOQUOTES : ENT_NOQUOTES),
-							'UTF-8');
+			$this->errstr = htmlspecialchars($fstr, ENT_XML1 | ENT_NOQUOTES, 'UTF-8');
 		}
 		elseif ( ! is_object($val))
 		{
@@ -1030,7 +1027,7 @@ class XML_RPC_Response
  *
  * @category	XML-RPC
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/xmlrpc.html
+ * @link		https://codeigniter.com/user_guide/libraries/xmlrpc.html
  */
 class XML_RPC_Message extends CI_Xmlrpc
 {
@@ -1649,7 +1646,7 @@ class XML_RPC_Message extends CI_Xmlrpc
  *
  * @category	XML-RPC
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/xmlrpc.html
+ * @link		https://codeigniter.com/user_guide/libraries/xmlrpc.html
  */
 class XML_RPC_Values extends CI_Xmlrpc
 {
diff --git a/system/libraries/Xmlrpcs.php b/system/libraries/Xmlrpcs.php
index 00d1feca6..21de937c8 100644
--- a/system/libraries/Xmlrpcs.php
+++ b/system/libraries/Xmlrpcs.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -56,7 +56,7 @@ if ( ! class_exists('CI_Xmlrpc', FALSE))
  * @subpackage	Libraries
  * @category	XML-RPC
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/xmlrpc.html
+ * @link		https://codeigniter.com/user_guide/libraries/xmlrpc.html
  */
 class CI_Xmlrpcs extends CI_Xmlrpc {
 
@@ -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
diff --git a/system/libraries/Zip.php b/system/libraries/Zip.php
index 3e98ac568..d6974b13a 100644
--- a/system/libraries/Zip.php
+++ b/system/libraries/Zip.php
@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2015, 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
@@ -28,10 +28,10 @@
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	http://codeigniter.com
+ * @link	https://codeigniter.com
  * @since	Version 1.0.0
  * @filesource
  */
@@ -50,7 +50,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Encryption
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/zip.html
+ * @link		https://codeigniter.com/user_guide/libraries/zip.html
  */
 class CI_Zip {
 
@@ -106,12 +106,21 @@ class CI_Zip {
 	public $compression_level = 2;
 
 	/**
+	 * mbstring.func_override flag
+	 *
+	 * @var	bool
+	 */
+	protected static $func_override;
+
+	/**
 	 * Initialize zip compression class
 	 *
 	 * @return	void
 	 */
 	public function __construct()
 	{
+		isset(self::$func_override) OR self::$func_override = (extension_loaded('mbstring') && ini_get('mbstring.func_override'));
+
 		$this->now = time();
 		log_message('info', 'Zip Compression Class Initialized');
 	}
@@ -182,7 +191,7 @@ class CI_Zip {
 			.pack('V', 0) // crc32
 			.pack('V', 0) // compressed filesize
 			.pack('V', 0) // uncompressed filesize
-			.pack('v', strlen($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 +490,40 @@ class CI_Zip {
 		return $this;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param	string	$str
+	 * @return	int
+	 */
+	protected static function strlen($str)
+	{
+		return (self::$func_override)
+			? mb_strlen($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_override)
+		{
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length)
+			? substr($str, $start, $length)
+			: substr($str, $start);
+	}
 }