Merge branch 'develop' of git://github.com/EllisLab/CodeIgniter into develop

Conflicts:
	user_guide_src/source/changelog.rst

75 files changed, 3562 insertions, 2606 deletions

diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index 8159b19f5..f3592eaf9 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -50,7 +50,7 @@
  *  Load the global functions
  * ------------------------------------------------------
  */
-	require(BASEPATH.'core/Common.php');
+	require_once(BASEPATH.'core/Common.php');
 
 /*
  * ------------------------------------------------------
diff --git a/system/core/Common.php b/system/core/Common.php
index 06b162264..2dd31d3e9 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -150,7 +150,7 @@ if ( ! function_exists('load_class'))
 
 				if (class_exists($name) === FALSE)
 				{
-					require($path.$directory.'/'.$class.'.php');
+					require_once($path.$directory.'/'.$class.'.php');
 				}
 
 				break;
@@ -164,7 +164,7 @@ if ( ! function_exists('load_class'))
 
 			if (class_exists($name) === FALSE)
 			{
-				require(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.'.php');
+				require_once(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.'.php');
 			}
 		}
 
@@ -330,6 +330,24 @@ if ( ! function_exists('get_mimes'))
 
 // ------------------------------------------------------------------------
 
+if ( ! function_exists('is_https'))
+{
+	/**
+	 * Is HTTPS?
+	 *
+	 * Determines if the application is accessed via an encrypted
+	 * (HTTPS) connection.
+	 *
+	 * @return	bool
+	 */
+	function is_https()
+	{
+		return ( ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off');
+	}
+}
+
+// ------------------------------------------------------------------------
+
 if ( ! function_exists('show_error'))
 {
 	/**
@@ -488,13 +506,9 @@ if ( ! function_exists('set_status_header'))
 		{
 			header('Status: '.$code.' '.$text, TRUE);
 		}
-		elseif ($server_protocol === 'HTTP/1.0')
-		{
-			header('HTTP/1.0 '.$code.' '.$text, TRUE, $code);
-		}
 		else
 		{
-			header('HTTP/1.1 '.$code.' '.$text, TRUE, $code);
+			header(($server_protocol ? $server_protocol : 'HTTP/1.1').' '.$code.' '.$text, TRUE, $code);
 		}
 	}
 }
@@ -524,18 +538,17 @@ if ( ! function_exists('_exception_handler'))
 	{
 		$_error =& load_class('Exceptions', 'core');
 
-		// Should we display the error? We'll get the current error_reporting
+		// Should we ignore the error? We'll get the current error_reporting
 		// level and add its bits with the severity bits to find out.
-		// And respect display_errors
-		if (($severity & error_reporting()) === $severity && (bool) ini_get('display_errors') === TRUE)
+		if (($severity & error_reporting()) !== $severity)
 		{
-			$_error->show_php_error($severity, $message, $filepath, $line);
+			return;
 		}
 
-		// Should we log the error? No? We're done...
-		if (config_item('log_threshold') === 0)
+		// Should we display the error?
+		if ((bool) ini_get('display_errors') === TRUE)
 		{
-			return;
+			$_error->show_php_error($severity, $message, $filepath, $line);
 		}
 
 		$_error->log_exception($severity, $message, $filepath, $line);
@@ -598,5 +611,44 @@ if ( ! function_exists('html_escape'))
 	}
 }
 
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('_stringify_attributes'))
+{
+	/**
+	 * Stringify attributes for use in HTML tags.
+	 *
+	 * Helper function used to convert a string, array, or object
+	 * of attributes to a string.
+	 *
+	 * @param	mixed	string, array, object
+	 * @param	bool
+	 * @return	string
+	 */
+	function _stringify_attributes($attributes, $js = FALSE)
+	{
+		$atts = NULL;
+
+		if (empty($attributes))
+		{
+			return $atts;
+		}
+
+		if (is_string($attributes))
+		{
+			return ' '.$attributes;
+		}
+
+		$attributes = (array) $attributes;
+
+		foreach ($attributes as $key => $val)
+		{
+			$atts .= ($js) ? $key.'='.$val.',' : ' '.$key.'="'.$val.'"';
+		}
+
+		return rtrim($atts, ',');
+	}
+}
+
 /* End of file Common.php */
 /* Location: ./system/core/Common.php */
\ No newline at end of file
diff --git a/system/core/Config.php b/system/core/Config.php
index 2f6a9e085..e78128c76 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -75,7 +75,7 @@ class CI_Config {
 		{
 			if (isset($_SERVER['HTTP_HOST']))
 			{
-				$base_url = ( ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off') ? 'https' : 'http';
+				$base_url = is_https() ? 'https' : 'http';
 				$base_url .= '://'.$_SERVER['HTTP_HOST']
 					.str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);
 			}
@@ -102,7 +102,7 @@ class CI_Config {
 	{
 		$file = ($file === '') ? 'config' : str_replace('.php', '', $file);
 		$found = $loaded = FALSE;
-		
+
 		$check_locations = defined('ENVIRONMENT')
 			? array(ENVIRONMENT.'/'.$file, $file)
 			: array($file);
diff --git a/system/core/Controller.php b/system/core/Controller.php
index 491414807..9196958ae 100644
--- a/system/core/Controller.php
+++ b/system/core/Controller.php
@@ -42,6 +42,7 @@ class CI_Controller {
 	/**
 	 * Reference to the global CI instance
 	 *
+	 * @static
 	 * @var	object
 	 */
 	private static $instance;
@@ -71,6 +72,7 @@ class CI_Controller {
 	/**
 	 * Return the CI object
 	 *
+	 * @static
 	 * @return	object
 	 */
 	public static function &get_instance()
diff --git a/system/core/Input.php b/system/core/Input.php
index 162e40c85..ec935d531 100644
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -328,39 +328,121 @@ class CI_Input {
 			return $this->ip_address;
 		}
 
-		if (config_item('proxy_ips') != '' && $this->server('HTTP_X_FORWARDED_FOR') && $this->server('REMOTE_ADDR'))
+		$proxy_ips = config_item('proxy_ips');
+		if ( ! empty($proxy_ips) && ! is_array($proxy_ips))
 		{
-			$proxies = preg_split('/[\s,]/', config_item('proxy_ips'), -1, PREG_SPLIT_NO_EMPTY);
-			$proxies = is_array($proxies) ? $proxies : array($proxies);
-
-			$this->ip_address = in_array($_SERVER['REMOTE_ADDR'], $proxies) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR'];
-		}
-		elseif ( ! $this->server('HTTP_CLIENT_IP') && $this->server('REMOTE_ADDR'))
-		{
-			$this->ip_address = $_SERVER['REMOTE_ADDR'];
-		}
-		elseif ($this->server('REMOTE_ADDR') && $this->server('HTTP_CLIENT_IP'))
-		{
-			$this->ip_address = $_SERVER['HTTP_CLIENT_IP'];
-		}
-		elseif ($this->server('HTTP_CLIENT_IP'))
-		{
-			$this->ip_address = $_SERVER['HTTP_CLIENT_IP'];
-		}
-		elseif ($this->server('HTTP_X_FORWARDED_FOR'))
-		{
-			$this->ip_address = $_SERVER['HTTP_X_FORWARDED_FOR'];
+			$proxy_ips = explode(',', str_replace(' ', '', $proxy_ips));
 		}
 
-		if ($this->ip_address === FALSE)
-		{
-			return $this->ip_address = '0.0.0.0';
-		}
+		$this->ip_address = $this->server('REMOTE_ADDR');
 
-		if (strpos($this->ip_address, ',') !== FALSE)
+		if ($proxy_ips)
 		{
-			$x = explode(',', $this->ip_address);
-			$this->ip_address = trim(end($x));
+			foreach (array('HTTP_X_FORWARDED_FOR', 'HTTP_CLIENT_IP', 'HTTP_X_CLIENT_IP', 'HTTP_X_CLUSTER_CLIENT_IP') as $header)
+			{
+				if (($spoof = $this->server($header)) !== NULL)
+				{
+					// Some proxies typically list the whole chain of IP
+					// addresses through which the client has reached us.
+					// e.g. client_ip, proxy_ip1, proxy_ip2, etc.
+					if (strpos($spoof, ',') !== FALSE)
+					{
+						$spoof = explode(',', $spoof, 2);
+						$spoof = $spoof[0];
+					}
+
+					if ( ! $this->valid_ip($spoof))
+					{
+						$spoof = NULL;
+					}
+					else
+					{
+						break;
+					}
+				}
+			}
+
+			if ($spoof)
+			{
+				for ($i = 0, $c = count($proxy_ips); $i < $c; $i++)
+				{
+					// Check if we have an IP address or a subnet
+					if (strpos($proxy_ips[$i], '/') === FALSE)
+					{
+						// An IP address (and not a subnet) is specified.
+						// We can compare right away.
+						if ($proxy_ips[$i] === $this->ip_address)
+						{
+							$this->ip_address = $spoof;
+							break;
+						}
+
+						continue;
+					}
+
+					// We have a subnet ... now the heavy lifting begins
+					isset($separator) OR $separator = $this->valid_ip($this->ip_address, 'ipv6') ? ':' : '.';
+
+					// If the proxy entry doesn't match the IP protocol - skip it
+					if (strpos($proxy_ips[$i], $separator) === FALSE)
+					{
+						continue;
+					}
+
+					// Convert the REMOTE_ADDR IP address to binary, if needed
+					if ( ! isset($ip, $sprintf))
+					{
+						if ($separator === ':')
+						{
+							// Make sure we're have the "full" IPv6 format
+							$ip = explode(':',
+								str_replace('::',
+									str_repeat(':', 9 - substr_count($this->ip_address, ':')),
+									$this->ip_address
+								)
+							);
+
+							for ($i = 0; $i < 8; $i++)
+							{
+								$ip[$i] = intval($ip[$i], 16);
+							}
+
+							$sprintf = '%016b%016b%016b%016b%016b%016b%016b%016b';
+						}
+						else
+						{
+							$ip = explode('.', $this->ip_address);
+							$sprintf = '%08b%08b%08b%08b';
+						}
+
+						$ip = vsprintf($sprintf, $ip);
+					}
+
+					// Split the netmask length off the network address
+					list($netaddr, $masklen) = explode('/', $proxy_ips[$i], 2);
+
+					// Again, an IPv6 address is most likely in a compressed form
+					if ($separator === ':')
+					{
+						$netaddr = explode(':', str_replace('::', str_repeat(':', 9 - substr_count($netaddr, ':')), $netaddr));
+						for ($i = 0; $i < 8; $i++)
+						{
+							$netaddr[$i] = intval($netaddr[$i], 16);
+						}
+					}
+					else
+					{
+						$netaddr = explode('.', $netaddr);
+					}
+
+					// Convert to binary and finally compare
+					if (strncmp($ip, vsprintf($sprintf, $netaddr), $masklen) === 0)
+					{
+						$this->ip_address = $spoof;
+						break;
+					}
+				}
+			}
 		}
 
 		if ( ! $this->valid_ip($this->ip_address))
@@ -518,7 +600,7 @@ class CI_Input {
 		$_SERVER['PHP_SELF'] = strip_tags($_SERVER['PHP_SELF']);
 
 		// CSRF Protection check
-		if ($this->_enable_csrf === TRUE)
+		if ($this->_enable_csrf === TRUE && ! $this->is_cli_request())
 		{
 			$this->security->csrf_verify();
 		}
diff --git a/system/core/Loader.php b/system/core/Loader.php
index 0bc6e844a..5de2e5dde 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -409,8 +409,8 @@ class CI_Loader {
 	 * 1. The name of the "view" file to be included.
 	 * 2. An associative array of data to be extracted for use in the view.
 	 * 3. TRUE/FALSE - whether to return the data or load it. In
-	 *    some cases it's advantageous to be able to return data so that
-	 *    a developer can process it in some way.
+	 *	some cases it's advantageous to be able to return data so that
+	 *	a developer can process it in some way.
 	 *
 	 * @param	string
 	 * @param	array
@@ -633,13 +633,7 @@ class CI_Loader {
 			{
 				$this->driver($driver);
 			}
-			return FALSE;
-		}
-
-		if ( ! class_exists('CI_Driver_Library'))
-		{
-			// we aren't instantiating an object here, that'll be done by the Library itself
-			require BASEPATH.'libraries/Driver.php';
+			return;
 		}
 
 		if ($library === '')
@@ -695,7 +689,7 @@ class CI_Loader {
 	 */
 	public function get_package_paths($include_base = FALSE)
 	{
-		return $include_base === TRUE ? $this->_ci_library_paths : $this->_ci_model_paths;
+		return ($include_base === TRUE) ? $this->_ci_library_paths : $this->_ci_model_paths;
 	}
 
 	// --------------------------------------------------------------------
@@ -785,11 +779,11 @@ class CI_Loader {
 			$_ci_ext = pathinfo($_ci_view, PATHINFO_EXTENSION);
 			$_ci_file = ($_ci_ext === '') ? $_ci_view.'.php' : $_ci_view;
 
-			foreach ($this->_ci_view_paths as $view_file => $cascade)
+			foreach ($this->_ci_view_paths as $_ci_view_file => $cascade)
 			{
-				if (file_exists($view_file.$_ci_file))
+				if (file_exists($_ci_view_file.$_ci_file))
 				{
-					$_ci_path = $view_file.$_ci_file;
+					$_ci_path = $_ci_view_file.$_ci_file;
 					$file_exists = TRUE;
 					break;
 				}
@@ -837,10 +831,10 @@ class CI_Loader {
 		 * We buffer the output for two reasons:
 		 * 1. Speed. You get a significant speed boost.
 		 * 2. So that the final rendered template can be post-processed by
-		 *    the output class. Why do we need post processing? For one thing,
-		 *    in order to show the elapsed page load time. Unless we can
-		 *    intercept the content right before it's sent to the browser and
-		 *    then stop the timer it won't be accurate.
+		 *	the output class. Why do we need post processing? For one thing,
+		 *	in order to show the elapsed page load time. Unless we can
+		 *	intercept the content right before it's sent to the browser and
+		 *	then stop the timer it won't be accurate.
 		 */
 		ob_start();
 
@@ -915,6 +909,13 @@ class CI_Loader {
 
 			// Get the filename from the path
 			$class = substr($class, $last_slash);
+
+			// Check for match and driver base class
+			if (strtolower(trim($subdir, '/')) == strtolower($class) && ! class_exists('CI_Driver_Library'))
+			{
+				// We aren't instantiating an object here, just making the base class available
+				require BASEPATH.'libraries/Driver.php';
+			}
 		}
 
 		// We'll test for both lowercase and capitalized versions of the file name
@@ -996,14 +997,19 @@ class CI_Loader {
 				$this->_ci_loaded_files[] = $filepath;
 				return $this->_ci_init_class($class, '', $params, $object_name);
 			}
-
 		} // END FOREACH
 
 		// One last attempt. Maybe the library is in a subdirectory, but it wasn't specified?
 		if ($subdir === '')
 		{
 			$path = strtolower($class).'/'.$class;
-			return $this->_ci_load_class($path, $params);
+			return $this->_ci_load_class($path, $params, $object_name);
+		}
+		elseif (ucfirst($subdir) != $subdir)
+		{
+			// Lowercase subdir failed - retry capitalized
+			$path = ucfirst($subdir).$class;
+			return $this->_ci_load_class($path, $params, $object_name);
 		}
 
 		// If we got this far we were unable to find the requested class.
@@ -1193,6 +1199,15 @@ class CI_Loader {
 			}
 		}
 
+		// Autoload drivers
+		if (isset($autoload['drivers']))
+		{
+			foreach ($autoload['drivers'] as $item)
+			{
+				$this->driver($item);
+			}
+		}
+
 		// Autoload models
 		if (isset($autoload['model']))
 		{
diff --git a/system/core/Output.php b/system/core/Output.php
index 5ec8c4bc0..aa0e05dc4 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -204,7 +204,8 @@ class CI_Output {
 	/**
 	 * Set Content Type Header
 	 *
-	 * @param	string	extension of the file we're outputting
+	 * @param	string	$mime_type	extension of the file we're outputting
+	 * @param	string	$charset = NULL
 	 * @return	void
 	 */
 	public function set_content_type($mime_type, $charset = NULL)
@@ -552,13 +553,13 @@ class CI_Output {
 		fclose($fp);
 
 		// Strip out the embedded timestamp
-		if ( ! preg_match('/(\d+TS--->)/', $cache, $match))
+		if ( ! preg_match('/^(\d+)TS--->/', $cache, $match))
 		{
 			return FALSE;
 		}
 
 		$last_modified = filemtime($cache_path);
-		$expire = trim(str_replace('TS--->', '', $match[1]));
+		$expire = $match[1];
 
 		// Has the file expired?
 		if ($_SERVER['REQUEST_TIME'] >= $expire && is_really_writable($cache_path))
@@ -575,7 +576,7 @@ class CI_Output {
 		}
 
 		// Display the cache
-		$this->_display(str_replace($match[0], '', $cache));
+		$this->_display(substr($cache, strlen($match[0])));
 		log_message('debug', 'Cache file is current. Sending it to browser.');
 		return TRUE;
 	}
diff --git a/system/core/Security.php b/system/core/Security.php
index b22d2cf19..2fbc5b34c 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -198,7 +198,7 @@ class CI_Security {
 		$expire = time() + $this->_csrf_expire;
 		$secure_cookie = (bool) config_item('cookie_secure');
 
-		if ($secure_cookie && (empty($_SERVER['HTTPS']) OR strtolower($_SERVER['HTTPS']) === 'off'))
+		if ($secure_cookie && ! is_https())
 		{
 			return FALSE;
 		}
diff --git a/system/core/URI.php b/system/core/URI.php
index 6a8b1a5ac..15e6a5599 100644
--- a/system/core/URI.php
+++ b/system/core/URI.php
@@ -165,11 +165,8 @@ class CI_URI {
 	 */
 	protected function _set_uri_string($str)
 	{
-		// Filter out control characters
-		$str = remove_invisible_characters($str, FALSE);
-
-		// If the URI contains only a slash we'll kill it
-		$this->uri_string = ($str === '/') ? '' : $str;
+		// Filter out control characters and trim slashes
+		$this->uri_string = trim(remove_invisible_characters($str, FALSE), '/');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/core/Utf8.php b/system/core/Utf8.php
index 0a7ec501c..1ff02981b 100644
--- a/system/core/Utf8.php
+++ b/system/core/Utf8.php
@@ -49,30 +49,31 @@ class CI_Utf8 {
 	{
 		log_message('debug', 'Utf8 Class Initialized');
 
-		global $CFG;
+		$charset = strtoupper(config_item('charset'));
+
+		// set internal encoding for multibyte string functions if necessary
+		// and set a flag so we don't have to repeatedly use extension_loaded()
+		// or function_exists()
+		if (extension_loaded('mbstring'))
+		{
+			define('MB_ENABLED', TRUE);
+			mb_internal_encoding($charset);
+		}
+		else
+		{
+			define('MB_ENABLED', FALSE);
+		}
+
 
 		if (
-			@preg_match('/./u', 'é') === 1		// PCRE must support UTF-8
-			&& function_exists('iconv')			// iconv must be installed
-			&& (bool) @ini_get('mbstring.func_overload') !== TRUE	// Multibyte string function overloading cannot be enabled
-			&& $CFG->item('charset') === 'UTF-8'		// Application charset must be UTF-8
+			@preg_match('/./u', 'é') === 1	// PCRE must support UTF-8
+			&& function_exists('iconv')	// iconv must be installed
+			&& MB_ENABLED === TRUE		// mbstring must be enabled
+			&& $charset === 'UTF-8'		// Application charset must be UTF-8
 			)
 		{
 			define('UTF8_ENABLED', TRUE);
 			log_message('debug', 'UTF-8 Support Enabled');
-
-			// set internal encoding for multibyte string functions if necessary
-			// and set a flag so we don't have to repeatedly use extension_loaded()
-			// or function_exists()
-			if (extension_loaded('mbstring'))
-			{
-				define('MB_ENABLED', TRUE);
-				mb_internal_encoding('UTF-8');
-			}
-			else
-			{
-				define('MB_ENABLED', FALSE);
-			}
 		}
 		else
 		{
@@ -135,7 +136,7 @@ class CI_Utf8 {
 		{
 			return @iconv($encoding, 'UTF-8', $str);
 		}
-		elseif (function_exists('mb_convert_encoding'))
+		elseif (MB_ENABLED === TRUE)
 		{
 			return @mb_convert_encoding($str, 'UTF-8', $encoding);
 		}
diff --git a/system/database/DB_cache.php b/system/database/DB_cache.php
index ba9110382..d07c755c6 100644
--- a/system/database/DB_cache.php
+++ b/system/database/DB_cache.php
@@ -37,12 +37,20 @@ class CI_DB_Cache {
 	public $CI;
 	public $db;	// allows passing of db object so that multiple database connections and returned db objects can be supported
 
+	/**
+	 * Constructor
+	 *
+	 * @param	object	&$db
+	 * @return	void
+	 */
 	public function __construct(&$db)
 	{
 		// Assign the main CI object to $this->CI and load the file helper since we use it a lot
 		$this->CI =& get_instance();
 		$this->db =& $db;
 		$this->CI->load->helper('file');
+
+		$this->check_path();
 	}
 
 	// --------------------------------------------------------------------
@@ -66,7 +74,9 @@ class CI_DB_Cache {
 		}
 
 		// Add a trailing slash to the path if needed
-		$path = preg_replace('/(.+?)\/*$/', '\\1/',  $path);
+		$path = realpath($path)
+			? rtrim(realpath($path), DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR
+			: rtrim($path, '/').'/';
 
 		if ( ! is_dir($path) OR ! is_really_writable($path))
 		{
@@ -86,15 +96,11 @@ class CI_DB_Cache {
 	 * The URI being requested will become the name of the cache sub-folder.
 	 * An MD5 hash of the SQL statement will become the cache file name
 	 *
+	 * @param	string	$sql
 	 * @return	string
 	 */
 	public function read($sql)
 	{
-		if ( ! $this->check_path())
-		{
-			return $this->db->cache_off();
-		}
-
 		$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
 		$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
 		$filepath = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'.md5($sql);
@@ -112,15 +118,12 @@ class CI_DB_Cache {
 	/**
 	 * Write a query to a cache file
 	 *
+	 * @param	string	$sql
+	 * @param	object	$object
 	 * @return	bool
 	 */
 	public function write($sql, $object)
 	{
-		if ( ! $this->check_path())
-		{
-			return $this->db->cache_off();
-		}
-
 		$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
 		$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
 		$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/';
@@ -150,7 +153,9 @@ class CI_DB_Cache {
 	/**
 	 * Delete cache files within a particular directory
 	 *
-	 * @return	bool
+	 * @param	string	$segment_one = ''
+	 * @param	string	$segment_two = ''
+	 * @return	void
 	 */
 	public function delete($segment_one = '', $segment_two = '')
 	{
@@ -173,7 +178,7 @@ class CI_DB_Cache {
 	/**
 	 * Delete all existing cache files
 	 *
-	 * @return	bool
+	 * @return	void
 	 */
 	public function delete_all()
 	{
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index d63a1d955..7f1434fc1 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -51,6 +51,7 @@ abstract class CI_DB_driver {
 	public $char_set		= 'utf8';
 	public $dbcollat		= 'utf8_general_ci';
 	public $autoinit		= TRUE; // Whether to automatically initialize the DB
+	public $encrypt			= FALSE;
 	public $swap_pre		= '';
 	public $port			= '';
 	public $pconnect		= FALSE;
@@ -78,6 +79,10 @@ abstract class CI_DB_driver {
 	protected $_protect_identifiers		= TRUE;
 	protected $_reserved_identifiers	= array('*'); // Identifiers that should NOT be escaped
 
+	// clause and character used for LIKE escape sequences
+	protected $_like_escape_str = " ESCAPE '%s' ";
+	protected $_like_escape_chr = '!';
+
 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is
@@ -305,8 +310,9 @@ abstract class CI_DB_driver {
 	 * FALSE upon failure, and if the $db_debug variable is set to TRUE
 	 * will raise an error.
 	 *
-	 * @param	string	An SQL query string
-	 * @param	array	An array of binding data
+	 * @param	string	$sql
+	 * @param	array	$binds = FALSE		An array of binding data
+	 * @param	bool	$return_object = NULL
 	 * @return	mixed
 	 */
 	public function query($sql, $binds = FALSE, $return_object = NULL)
@@ -509,6 +515,7 @@ abstract class CI_DB_driver {
 	 * If strict mode is disabled, each group is treated autonomously, meaning
 	 * a failure of one group will not affect any others
 	 *
+	 * @param	bool	$mode = TRUE
 	 * @return	void
 	 */
 	public function trans_strict($mode = TRUE)
@@ -521,6 +528,7 @@ abstract class CI_DB_driver {
 	/**
 	 * Start Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	void
 	 */
 	public function trans_start($test_mode = FALSE)
@@ -669,7 +677,7 @@ abstract class CI_DB_driver {
 	 */
 	public function is_write_type($sql)
 	{
-		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s+/i', $sql);
+		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s+/i', $sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -805,6 +813,7 @@ abstract class CI_DB_driver {
 	/**
 	 * Returns an array of table names
 	 *
+	 * @param	string	$constrain_by_prefix = FALSE
 	 * @return	array
 	 */
 	public function list_tables($constrain_by_prefix = FALSE)
@@ -859,6 +868,7 @@ abstract class CI_DB_driver {
 	/**
 	 * Determine if a particular table exists
 	 *
+	 * @param	string	$table_name
 	 * @return	bool
 	 */
 	public function table_exists($table_name)
@@ -1119,30 +1129,19 @@ abstract class CI_DB_driver {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @param	array	the like clause
 	 * @return	string
 	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
 		foreach ($values as $key => $val)
 		{
 			$valstr[] = $key.' = '.$val;
 		}
 
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
 		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
-			.$where
-			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
-			.($limit ? ' LIMIT '.$limit : '');
+			.$this->_compile_wh('qb_where')
+			.$this->_compile_order_by()
+			.($this->qb_limit ? ' LIMIT '.$this->qb_limit : '');
 	}
 
 	// --------------------------------------------------------------------
@@ -1155,7 +1154,7 @@ abstract class CI_DB_driver {
 	 */
 	protected function _has_operator($str)
 	{
-		return (bool) preg_match('/(\s|<|>|!|=|IS NULL|IS NOT NULL|BETWEEN)/i', trim($str));
+		return (bool) preg_match('/(<|>|!|=|\sIS NULL|\sIS NOT NULL|\sBETWEEN|\sLIKE|\sIN\s*\(|\s)/i', trim($str));
 	}
 
 	// --------------------------------------------------------------------
@@ -1168,8 +1167,30 @@ abstract class CI_DB_driver {
 	 */
 	protected function _get_operator($str)
 	{
-		return preg_match('/(=|!|<|>| IS NULL| IS NOT NULL| BETWEEN)/i', $str, $match)
-			? $match[1] : FALSE;
+		static $_operators;
+
+		if (empty($_operators))
+		{
+			$_les = ($this->_like_escape_str !== '')
+				? '\s+'.preg_quote(trim(sprintf($this->_like_escape_str, $this->_like_escape_chr)))
+				: '';
+			$_operators = array(
+				'\s*(?:<|>|!)?=\s*',		// =, <=, >=, !=
+				'\s*<>?\s*',			// <, <>
+				'\s*>\s*',			// >
+				'\s+IS NULL',			// IS NULL
+				'\s+IS NOT NULL',		// IS NOT NULL
+				'\s+BETWEEN\s+\S+\s+AND\s+\S+',	// BETWEEN value AND value
+				'\s+IN\s*\([^\)]+\)',		// IN(list)
+				'\s+NOT IN\s*\([^\)]+\)',	// NOT IN (list)
+				'\s+LIKE\s+\S+'.$_les,		// LIKE 'expr'[ ESCAPE '%s']
+				'\s+NOT LIKE\s+\S+'.$_les	// NOT LIKE 'expr'[ ESCAPE '%s']
+			);
+
+		}
+
+		return preg_match('/'.implode('|', $_operators).'/i', $str, $match)
+			? $match[0] : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1177,8 +1198,8 @@ abstract class CI_DB_driver {
 	/**
 	 * Enables a native PHP function to be run, using a platform agnostic wrapper.
 	 *
-	 * @param	string	the function name
-	 * @param	mixed	any parameters needed by the function
+	 * @param	string	$function	the function name
+	 * @param	mixed	$param,...	optional parameters needed by the function
 	 * @return	mixed
 	 */
 	public function call_function($function)
@@ -1242,6 +1263,8 @@ abstract class CI_DB_driver {
 	/**
 	 * Delete the cache files associated with a particular URI
 	 *
+	 * @param	string	$segment_one = ''
+	 * @param	string	$segment_two = ''
 	 * @return	bool
 	 */
 	public function cache_delete($segment_one = '', $segment_two = '')
@@ -1343,7 +1366,7 @@ abstract class CI_DB_driver {
 		}
 		else
 		{
-			$message = ( ! is_array($error)) ? array(str_replace('%s', $swap, $LANG->line($error))) : $error;
+			$message = is_array($error) ? $error : array(str_replace('%s', $swap, $LANG->line($error)));
 		}
 
 		// Find the most likely culprit of the error by going through
@@ -1352,7 +1375,13 @@ abstract class CI_DB_driver {
 		$trace = debug_backtrace();
 		foreach ($trace as $call)
 		{
-			if (isset($call['file']) && strpos($call['file'], BASEPATH.'database') === FALSE)
+			// We'll need this on Windows, as APPPATH and BASEPATH will always use forward slashes
+			if (DIRECTORY_SEPARATOR !== '/')
+			{
+				$call['file'] = str_replace('\\', '/', $call['file']);
+			}
+
+			if (isset($call['file'], $call['class']) && strpos($call['file'], BASEPATH.'database') === FALSE && strpos($call['class'], 'Loader') !== FALSE)
 			{
 				// Found it - use a relative path for safety
 				$message[] = 'Filename: '.str_replace(array(APPPATH, BASEPATH), '', $call['file']);
diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 91f9d560c..119d78d38 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -37,7 +37,7 @@ abstract class CI_DB_forge {
 	public $fields		= array();
 	public $keys		= array();
 	public $primary_keys	= array();
-	public $db_char_set	=	'';
+	public $db_char_set	= '';
 
 	// Platform specific SQL strings
 	protected $_create_database	= 'CREATE DATABASE %s';
@@ -45,6 +45,11 @@ abstract class CI_DB_forge {
 	protected $_drop_table		= 'DROP TABLE IF EXISTS %s';
 	protected $_rename_table	= 'ALTER TABLE %s RENAME TO %s';
 
+	/**
+	 * Constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		// Assign the main database object to $this->db
@@ -206,7 +211,8 @@ abstract class CI_DB_forge {
 	/**
 	 * Create Table
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table = ''
+	 * @param	bool	$if_not_exists = FALSE
 	 * @return	bool
 	 */
 	public function create_table($table = '', $if_not_exists = FALSE)
@@ -378,9 +384,8 @@ abstract class CI_DB_forge {
 	/**
 	 * Column Modify
 	 *
-	 * @param	string	the table name
-	 * @param	string	the column name
-	 * @param	string	the column definition
+	 * @param	string	$table = ''
+	 * @param	string	$field = array()	column definition
 	 * @return	bool
 	 */
 	public function modify_column($table = '', $field = array())
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index 479b7f24a..5ea9643fe 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -47,7 +47,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	protected $qb_from			= array();
 	protected $qb_join			= array();
 	protected $qb_where			= array();
-	protected $qb_like			= array();
 	protected $qb_groupby			= array();
 	protected $qb_having			= array();
 	protected $qb_keys			= array();
@@ -55,7 +54,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	protected $qb_offset			= FALSE;
 	protected $qb_orderby			= array();
 	protected $qb_set			= array();
-	protected $qb_wherein			= array();
 	protected $qb_aliased_tables		= array();
 	protected $qb_store_array		= array();
 	protected $qb_where_group_started	= FALSE;
@@ -184,15 +182,17 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Processing Function for the four functions above:
+	 * Processing Function for the following functions:
 	 *
 	 *	select_max()
 	 *	select_min()
 	 *	select_avg()
 	 *	select_sum()
 	 *
-	 * @param	string	the field
-	 * @param	string	an alias
+	 *
+	 * @param	string	$select = ''	field name
+	 * @param	string	$alias = ''
+	 * @param	string	$type = 'MAX'
 	 * @return	object
 	 */
 	protected function _max_min_avg_sum($select = '', $alias = '', $type = 'MAX')
@@ -417,7 +417,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	public function where($key, $value = NULL, $escape = NULL)
 	{
-		return $this->_where($key, $value, 'AND ', $escape);
+		return $this->_wh('qb_where', $key, $value, 'AND ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -435,24 +435,27 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	public function or_where($key, $value = NULL, $escape = NULL)
 	{
-		return $this->_where($key, $value, 'OR ', $escape);
+		return $this->_wh('qb_where', $key, $value, 'OR ', $escape);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where
+	 * WHERE, HAVING
 	 *
-	 * Called by where() or or_where()
+	 * Called by where(), or_where(), having(), or_having()
 	 *
+	 * @param	string	'qb_where' or 'qb_having'
 	 * @param	mixed
 	 * @param	mixed
 	 * @param	string
-	 * @param	mixed
+	 * @param	bool
 	 * @return	object
 	 */
-	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
+	protected function _wh($qb_key, $key, $value = NULL, $type = 'AND ', $escape = NULL)
 	{
+		$qb_cache_key = ($qb_key === 'qb_having') ? 'qb_cache_having' : 'qb_cache_where';
+
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
@@ -463,17 +466,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+			$prefix = (count($this->$qb_key) === 0 && count($this->$qb_cache_key) === 0)
 				? $this->_group_get_type('')
 				: $this->_group_get_type($type);
 
-			if ($escape === TRUE)
-			{
-				$k = (($op = $this->_get_operator($k)) !== FALSE)
-					? $this->escape_identifiers(trim(substr($k, 0, strpos($k, $op)))).' '.strstr($k, $op)
-					: $this->escape_identifiers(trim($k));
-			}
-
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
 				// value appears not to have been set, assign the test to IS NULL
@@ -484,7 +480,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			{
 				if ($escape === TRUE)
 				{
-					$v = ' '.$this->escape($v);
+					$v = ' '.(is_int($v) ? $v : $this->escape($v));
 				}
 
 				if ( ! $this->_has_operator($k))
@@ -493,11 +489,11 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				}
 			}
 
-			$this->qb_where[] = $prefix.$k.$v;
+			$this->{$qb_key}[] = array('condition' => $prefix.$k.$v, 'escape' => $escape);
 			if ($this->qb_caching === TRUE)
 			{
-				$this->qb_cache_where[] = $prefix.$k.$v;
-				$this->qb_cache_exists[] = 'where';
+				$this->{$qb_cache_key}[] = array('condition' => $prefix.$k.$v, 'escape' => $escape);
+				$this->qb_cache_exists[] = substr($qb_key, 3);
 			}
 
 		}
@@ -510,11 +506,12 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Where_in
 	 *
-	 * Generates a WHERE field IN ('item', 'item') SQL query joined with
+	 * Generates a WHERE field IN('item', 'item') SQL query joined with
 	 * AND if appropriate
 	 *
-	 * @param	string	The field to search
-	 * @param	array	The values searched on
+	 * @param	string	$key = NULL	The field to search
+	 * @param	array	$values = NULL	The values searched on
+	 * @param	bool	$escape = NULL
 	 * @return	object
 	 */
 	public function where_in($key = NULL, $values = NULL, $escape = NULL)
@@ -525,13 +522,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where_in_or
+	 * Or_where_in
 	 *
-	 * Generates a WHERE field IN ('item', 'item') SQL query joined with
+	 * Generates a WHERE field IN('item', 'item') SQL query joined with
 	 * OR if appropriate
 	 *
-	 * @param	string	The field to search
-	 * @param	array	The values searched on
+	 * @param	string	$key = NULL	The field to search
+	 * @param	array	$values = NULL	The values searched on
+	 * @param	bool	$escape = NULL
 	 * @return	object
 	 */
 	public function or_where_in($key = NULL, $values = NULL, $escape = NULL)
@@ -544,11 +542,12 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Where_not_in
 	 *
-	 * Generates a WHERE field NOT IN ('item', 'item') SQL query joined
+	 * Generates a WHERE field NOT IN('item', 'item') SQL query joined
 	 * with AND if appropriate
 	 *
-	 * @param	string	The field to search
-	 * @param	array	The values searched on
+	 * @param	string	$key = NULL	The field to search
+	 * @param	array	$values = NULL	The values searched on
+	 * @param	bool	$escape = NULL
 	 * @return	object
 	 */
 	public function where_not_in($key = NULL, $values = NULL, $escape = NULL)
@@ -559,13 +558,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where_not_in_or
+	 * Or_where_not_in
 	 *
-	 * Generates a WHERE field NOT IN ('item', 'item') SQL query joined
+	 * Generates a WHERE field NOT IN('item', 'item') SQL query joined
 	 * with OR if appropriate
 	 *
-	 * @param	string	The field to search
-	 * @param	array	The values searched on
+	 * @param	string	$key = NULL	The field to search
+	 * @param	array	$values = NULL	The values searched on
+	 * @param	bool	$escape = NULL
 	 * @return	object
 	 */
 	public function or_where_not_in($key = NULL, $values = NULL, $escape = NULL)
@@ -578,12 +578,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Where_in
 	 *
-	 * Called by where_in, where_in_or, where_not_in, where_not_in_or
+	 * Called by where_in(), or_where_in(), where_not_in(), or_where_not_in()
 	 *
-	 * @param	string	The field to search
-	 * @param	array	The values searched on
-	 * @param	bool	If the statement would be IN or NOT IN
-	 * @param	string
+	 * @param	string	$key = NULL	The field to search
+	 * @param	array	$values = NULL	The values searched on
+	 * @param	bool	$not = FALSE	If the statement would be IN or NOT IN
+	 * @param	string	$type = 'AND '
+	 * @param	bool	$escape = NULL
 	 * @return	object
 	 */
 	protected function _where_in($key = NULL, $values = NULL, $not = FALSE, $type = 'AND ', $escape = NULL)
@@ -602,27 +603,25 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		$not = ($not) ? ' NOT' : '';
 
+		$where_in = array();
 		foreach ($values as $value)
 		{
-			$this->qb_wherein[] = $this->escape($value);
-		}
-
-		if ($escape === TRUE)
-		{
-			$key = $this->escape_identifiers(trim($key));
+			$where_in[] = $this->escape($value);
 		}
 
 		$prefix = (count($this->qb_where) === 0) ? $this->_group_get_type('') : $this->_group_get_type($type);
-		$this->qb_where[] = $where_in = $prefix.$key.$not.' IN ('.implode(', ', $this->qb_wherein).') ';
+		$where_in = array(
+			'condition' => $prefix.$key.$not.' IN('.implode(', ', $where_in).')',
+			'escape' => $escape
+		);
 
+		$this->qb_where[] = $where_in;
 		if ($this->qb_caching === TRUE)
 		{
 			$this->qb_cache_where[] = $where_in;
 			$this->qb_cache_exists[] = 'where';
 		}
 
-		// reset the array for multiple calls
-		$this->qb_wherein = array();
 		return $this;
 	}
 
@@ -635,12 +634,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * multiple calls with AND
 	 *
 	 * @param	mixed
-	 * @param	mixed
+	 * @param	string
+	 * @param	string
+	 * @param	bool
 	 * @return	object
 	 */
-	public function like($field, $match = '', $side = 'both')
+	public function like($field, $match = '', $side = 'both', $escape = NULL)
 	{
-		return $this->_like($field, $match, 'AND ', $side);
+		return $this->_like($field, $match, 'AND ', $side, '', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -652,12 +653,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * multiple calls with AND
 	 *
 	 * @param	mixed
-	 * @param	mixed
+	 * @param	string
+	 * @param	string
+	 * @param	bool
 	 * @return	object
 	 */
-	public function not_like($field, $match = '', $side = 'both')
+	public function not_like($field, $match = '', $side = 'both', $escape = NULL)
 	{
-		return $this->_like($field, $match, 'AND ', $side, 'NOT');
+		return $this->_like($field, $match, 'AND ', $side, 'NOT', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -669,12 +672,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * multiple calls with OR
 	 *
 	 * @param	mixed
-	 * @param	mixed
+	 * @param	string
+	 * @param	string
+	 * @param	bool
 	 * @return	object
 	 */
-	public function or_like($field, $match = '', $side = 'both')
+	public function or_like($field, $match = '', $side = 'both', $escape = NULL)
 	{
-		return $this->_like($field, $match, 'OR ', $side);
+		return $this->_like($field, $match, 'OR ', $side, '', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -686,12 +691,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * multiple calls with OR
 	 *
 	 * @param	mixed
-	 * @param	mixed
+	 * @param	string
+	 * @param	string
+	 * @param	bool
 	 * @return	object
 	 */
-	public function or_not_like($field, $match = '', $side = 'both')
+	public function or_not_like($field, $match = '', $side = 'both', $escape = NULL)
 	{
-		return $this->_like($field, $match, 'OR ', $side, 'NOT');
+		return $this->_like($field, $match, 'OR ', $side, 'NOT', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -699,56 +706,60 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	/**
 	 * Like
 	 *
-	 * Called by like() or orlike()
+	 * Called by like(), or_like(), not_like, or_not_like()
 	 *
 	 * @param	mixed
-	 * @param	mixed
 	 * @param	string
+	 * @param	string
+	 * @param	string
+	 * @param	string
+	 * @param	bool
 	 * @return	object
 	 */
-	protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $not = '')
+	protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $not = '', $escape = NULL)
 	{
 		if ( ! is_array($field))
 		{
 			$field = array($field => $match);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+		$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+			? $this->_group_get_type('') : $this->_group_get_type($type);
+
 		foreach ($field as $k => $v)
 		{
-			$k = $this->protect_identifiers($k);
-			$prefix = (count($this->qb_like) === 0) ? $this->_group_get_type('') : $this->_group_get_type($type);
 			$v = $this->escape_like_str($v);
 
 			if ($side === 'none')
 			{
-				$like_statement = "{$prefix} $k $not LIKE '{$v}'";
+				$like_statement = "{$prefix} {$k} {$not} LIKE '{$v}'";
 			}
 			elseif ($side === 'before')
 			{
-				$like_statement = "{$prefix} $k $not LIKE '%{$v}'";
+				$like_statement = "{$prefix} {$k} {$not} LIKE '%{$v}'";
 			}
 			elseif ($side === 'after')
 			{
-				$like_statement = "{$prefix} $k $not LIKE '{$v}%'";
+				$like_statement = "{$prefix} {$k} {$not} LIKE '{$v}%'";
 			}
 			else
 			{
-				$like_statement = "{$prefix} $k $not LIKE '%{$v}%'";
+				$like_statement = "{$prefix} {$k} {$not} LIKE '%{$v}%'";
 			}
 
 			// some platforms require an escape sequence definition for LIKE wildcards
 			if ($this->_like_escape_str !== '')
 			{
-				$like_statement = $like_statement.sprintf($this->_like_escape_str, $this->_like_escape_chr);
+				$like_statement .= sprintf($this->_like_escape_str, $this->_like_escape_chr);
 			}
 
-			$this->qb_like[] = $like_statement;
+			$this->qb_where[] = array('condition' => $like_statement, 'escape' => $escape);
 			if ($this->qb_caching === TRUE)
 			{
-				$this->qb_cache_like[] = $like_statement;
-				$this->qb_cache_exists[] = 'like';
+				$this->qb_cache_where[] = $like_statement;
+				$this->qb_cache_exists[] = 'where';
 			}
-
 		}
 
 		return $this;
@@ -769,11 +780,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		$this->qb_where_group_started = TRUE;
 		$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0) ? '' : $type;
-		$this->qb_where[] = $value = $prefix.$not.str_repeat(' ', ++$this->qb_where_group_count).' (';
+		$where = array(
+			'condition' => $prefix.$not.str_repeat(' ', ++$this->qb_where_group_count).' (',
+			'escape' => FALSE
+		);
 
+		$this->qb_where[] = $where;
 		if ($this->qb_caching)
 		{
-			$this->qb_cache_where[] = $value;
+			$this->qb_cache_where[] = $where;
 		}
 
 		return $this;
@@ -825,11 +840,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	public function group_end()
 	{
 		$this->qb_where_group_started = FALSE;
-		$this->qb_where[] = $value = str_repeat(' ', $this->qb_where_group_count--) . ')';
+		$where = array(
+			'condition' => str_repeat(' ', $this->qb_where_group_count--).')',
+			'escape' => FALSE
+		);
 
+		$this->qb_where[] = $where;
 		if ($this->qb_caching)
 		{
-			$this->qb_cache_where[] = $value;
+			$this->qb_cache_where[] = $where;
 		}
 
 		return $this;
@@ -862,13 +881,18 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * GROUP BY
 	 *
 	 * @param	string
+	 * @param	bool
 	 * @return	object
 	 */
-	public function group_by($by)
+	public function group_by($by, $escape = NULL)
 	{
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		if (is_string($by))
 		{
-			$by = explode(',', $by);
+			$by = ($escape === TRUE)
+				? explode(',', $by)
+				: array($by);
 		}
 
 		foreach ($by as $val)
@@ -877,8 +901,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 			if ($val !== '')
 			{
-				$this->qb_groupby[] = $val = $this->protect_identifiers($val);
+				$val = array('field' => $val, 'escape' => $escape);
 
+				$this->qb_groupby[] = $val;
 				if ($this->qb_caching === TRUE)
 				{
 					$this->qb_cache_groupby[] = $val;
@@ -902,9 +927,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function having($key, $value = '', $escape = NULL)
+	public function having($key, $value = NULL, $escape = NULL)
 	{
-		return $this->_having($key, $value, 'AND ', $escape);
+		return $this->_wh('qb_having', $key, $value, 'AND ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -919,60 +944,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function or_having($key, $value = '', $escape = NULL)
+	public function or_having($key, $value = NULL, $escape = NULL)
 	{
-		return $this->_having($key, $value, 'OR ', $escape);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Sets the HAVING values
-	 *
-	 * Called by having() or or_having()
-	 *
-	 * @param	string
-	 * @param	string
-	 * @param	string
-	 * @param	bool
-	 * @return	object
-	 */
-	protected function _having($key, $value = '', $type = 'AND ', $escape = NULL)
-	{
-		if ( ! is_array($key))
-		{
-			$key = array($key => $value);
-		}
-
-		is_bool($escape) OR $escape = $this->_protect_identifiers;
-
-		foreach ($key as $k => $v)
-		{
-			$prefix = (count($this->qb_having) === 0) ? '' : $type;
-
-			$k = $this->_has_operator($k)
-				? $this->protect_identifiers(substr($k, 0, strpos(rtrim($k), ' ')), FALSE, $escape).strchr(rtrim($k), ' ')
-				: $this->protect_identifiers($k, FALSE, $escape);
-
-			if ( ! $this->_has_operator($k))
-			{
-				$k .= ' = ';
-			}
-
-			if ($v !== '')
-			{
-				$v = ' '.$this->escape($v);
-			}
-
-			$this->qb_having[] = $prefix.$k.$v;
-			if ($this->qb_caching === TRUE)
-			{
-				$this->qb_cache_having[] = $prefix.$k.$v;
-				$this->qb_cache_exists[] = 'having';
-			}
-		}
-
-		return $this;
+		return $this->_wh('qb_having', $key, $value, 'OR ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -981,54 +955,50 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * Sets the ORDER BY value
 	 *
 	 * @param	string
-	 * @param	string	direction: asc or desc
+	 * @param	string	direction: ASC or DESC
 	 * @param	bool	enable field name escaping
 	 * @return	object
 	 */
 	public function order_by($orderby, $direction = '', $escape = NULL)
 	{
-		if (strtolower($direction) === 'random')
+		$direction = trim($direction);
+
+		if (strtolower($direction) === 'random' OR $orderby === $this->_random_keyword)
+		{
+			// Random ordered results don't need a field name
+			$orderby = $this->_random_keyword;
+			$direction = '';
+		}
+		elseif (empty($orderby))
 		{
-			$orderby = ''; // Random results want or don't need a field name
-			$direction = $this->_random_keyword;
+			return $this;
 		}
-		elseif (trim($direction) !== '')
+		elseif ($direction !== '')
 		{
-			$direction = in_array(strtoupper(trim($direction)), array('ASC', 'DESC'), TRUE) ? ' '.$direction : ' ASC';
+			$direction = in_array(strtoupper(trim($direction)), array('ASC', 'DESC'), TRUE) ? ' '.$direction : '';
 		}
 
 		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
-		if ($escape === TRUE && strpos($orderby, ',') !== FALSE)
+		if ($escape === FALSE)
 		{
-			$temp = array();
-			foreach (explode(',', $orderby) as $part)
-			{
-				$part = trim($part);
-				if ( ! in_array($part, $this->qb_aliased_tables))
-				{
-					$part = preg_match('/^(.+)\s+(ASC|DESC)$/i', $part, $matches)
-						? $this->protect_identifiers(rtrim($matches[1])).' '.$matches[2]
-						: $this->protect_identifiers($part);
-				}
-
-				$temp[] = $part;
-			}
-
-			$orderby = implode(', ', $temp);
+			$qb_orderby[] = array('field' => $orderby, 'direction' => $direction, 'escape' => FALSE);
 		}
-		elseif ($direction !== $this->_random_keyword && $escape === TRUE)
+		else
 		{
-			$orderby = preg_match('/^(.+)\s+(ASC|DESC)$/i', $orderby, $matches)
-				? $this->protect_identifiers(rtrim($matches[1])).' '.$matches[2]
-				: $this->protect_identifiers($orderby);
+			$qb_orderby = array();
+			foreach (explode(',', $orderby) as $field)
+			{
+				$qb_orderby[] = ($direction === '' && preg_match('/\s+(ASC|DESC)$/i', rtrim($field), $match, PREG_OFFSET_CAPTURE))
+					? array('field' => ltrim(substr($field, 0, $match[0][1])), 'direction' => ' '.$match[1][0], 'escape' => TRUE)
+					: array('field' => trim($field), 'direction' => $direction, 'escape' => TRUE);
+			}
 		}
 
-		$this->qb_orderby[] = $orderby_statement = $orderby.$direction;
-
+		$this->qb_orderby = array_merge($this->qb_orderby, $qb_orderby);
 		if ($this->qb_caching === TRUE)
 		{
-			$this->qb_cache_orderby[] = $orderby_statement;
+			$this->qb_cache_orderby = array_merge($this->qb_cache_orderby, $qb_orderby);
 			$this->qb_cache_exists[] = 'orderby';
 		}
 
@@ -1044,7 +1014,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	int	the offset value
 	 * @return	object
 	 */
-	public function limit($value, $offset = NULL)
+	public function limit($value, $offset = FALSE)
 	{
 		is_null($value) OR $this->qb_limit = (int) $value;
 		empty($offset) OR $this->qb_offset = (int) $offset;
@@ -1074,13 +1044,11 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.($offset ? $offset.', ' : '').$limit;
+		return $sql.' LIMIT '.($this->qb_offset ? $this->qb_offset.', ' : '').$this->qb_limit;
 	}
 
 	// --------------------------------------------------------------------
@@ -1213,9 +1181,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Allows the where clause, limit and offset to be added directly
 	 *
-	 * @param	string	the where clause
-	 * @param	string	the limit clause
-	 * @param	string	the offset clause
+	 * @param	string	$table = ''
+	 * @param	string	$where = NULL
+	 * @param	int	$limit = NULL
+	 * @param	int	$offset = NULL
 	 * @return	object
 	 */
 	public function get_where($table = '', $where = NULL, $limit = NULL, $offset = NULL)
@@ -1247,9 +1216,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Compiles batch insert strings and runs the queries
 	 *
-	 * @param	string	the table to retrieve the results from
-	 * @param	array	an associative array of insert values
-	 * @return	object
+	 * @param	string	$table = ''	table to insert into
+	 * @param	array	$set 		an associative array of insert values
+	 * @return	int	number of rows inserted or FALSE on failure
 	 */
 	public function insert_batch($table = '', $set = NULL)
 	{
@@ -1260,12 +1229,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		if (count($this->qb_set) === 0)
 		{
-			if ($this->db_debug)
-			{
-				// No valid data array. Folds in cases where keys and values did not match up
-				return $this->display_error('db_must_use_set');
-			}
-			return FALSE;
+			// No valid data array. Folds in cases where keys and values did not match up
+			return ($this->db_debug) ? $this->display_error('db_must_use_set') : FALSE;
 		}
 
 		if ($table === '')
@@ -1279,13 +1244,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		}
 
 		// Batch this baby
+		$affected_rows = 0;
 		for ($i = 0, $total = count($this->qb_set); $i < $total; $i += 100)
 		{
 			$this->query($this->_insert_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), $this->qb_keys, array_slice($this->qb_set, $i, 100)));
+			$affected_rows += $this->affected_rows();
 		}
 
 		$this->_reset_write();
-		return TRUE;
+		return $affected_rows;
 	}
 
 	// --------------------------------------------------------------------
@@ -1522,19 +1489,18 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
+	 * FROM tables
+	 *
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
 	 *
-	 * This public function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
+	 * Note: This is only used (and overriden) by MySQL and CUBRID.
 	 *
-	 * @param       array
-	 * @return      string
+	 * @return	string
 	 */
-	protected function _from_tables($tables)
+	protected function _from_tables()
 	{
-		is_array($tables) OR $tables = array($tables);
-
-		return (count($tables) === 1) ? $tables[0] : '('.implode(', ', $tables).')';
+		return implode(', ', $this->qb_from);
 	}
 
 	// --------------------------------------------------------------------
@@ -1558,7 +1524,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			return FALSE;
 		}
 
-		$sql = $this->_update($this->protect_identifiers($this->qb_from[0], TRUE, NULL, FALSE), $this->qb_set, $this->qb_where, $this->qb_orderby, $this->qb_limit);
+		$sql = $this->_update($this->protect_identifiers($this->qb_from[0], TRUE, NULL, FALSE), $this->qb_set);
 
 		if ($reset === TRUE)
 		{
@@ -1575,9 +1541,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Compiles an update string and runs the query
 	 *
-	 * @param	string	the table to retrieve the results from
-	 * @param	array	an associative array of update values
-	 * @param	mixed	the where clause
+	 * @param	string	$table = ''
+	 * @param	array	$set = NULL	an associative array of update values
+	 * @param	mixed	$where = NULL
+	 * @param	int	$limit = NULL
 	 * @return	object
 	 */
 	public function update($table = '', $set = NULL, $where = NULL, $limit = NULL)
@@ -1605,7 +1572,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$this->limit($limit);
 		}
 
-		$sql = $this->_update($this->protect_identifiers($this->qb_from[0], TRUE, NULL, FALSE), $this->qb_set, $this->qb_where, $this->qb_orderby, $this->qb_limit, $this->qb_like);
+		$sql = $this->_update($this->protect_identifiers($this->qb_from[0], TRUE, NULL, FALSE), $this->qb_set);
 
 		$this->_reset_write();
 		return $this->query($sql);
@@ -1652,7 +1619,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	string	the table to retrieve the results from
 	 * @param	array	an associative array of update values
 	 * @param	string	the where key
-	 * @return	bool
+	 * @return	int	number of rows affected or FALSE on failure
 	 */
 	public function update_batch($table = '', $set = NULL, $index = NULL)
 	{
@@ -1685,13 +1652,15 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		}
 
 		// Batch this baby
+		$affected_rows = 0;
 		for ($i = 0, $total = count($this->qb_set); $i < $total; $i += 100)
 		{
-			$this->query($this->_update_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), array_slice($this->qb_set, $i, 100), $this->protect_identifiers($index), $this->qb_where));
+			$this->query($this->_update_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), array_slice($this->qb_set, $i, 100), $this->protect_identifiers($index)));
+			$affected_rows += $this->affected_rows();
 		}
 
 		$this->_reset_write();
-		return TRUE;
+		return $affected_rows;
 	}
 
 	// --------------------------------------------------------------------
@@ -1852,7 +1821,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	mixed	the where clause
 	 * @param	mixed	the limit clause
 	 * @param	bool
-	 * @return	object
+	 * @return	mixed
 	 */
 	public function delete($table = '', $where = '', $limit = NULL, $reset_data = TRUE)
 	{
@@ -1872,10 +1841,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		{
 			foreach ($table as $single_table)
 			{
-				$this->delete($single_table, $where, $limit, FALSE);
+				$this->delete($single_table, $where, $limit, $reset_data);
 			}
-
-			$this->_reset_write();
 			return;
 		}
 		else
@@ -1893,12 +1860,12 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$this->limit($limit);
 		}
 
-		if (count($this->qb_where) === 0 && count($this->qb_wherein) === 0 && count($this->qb_like) === 0)
+		if (count($this->qb_where) === 0)
 		{
 			return ($this->db_debug) ? $this->display_error('db_del_must_use_where') : FALSE;
 		}
 
-		$sql = $this->_delete($table, $this->qb_where, $this->qb_like, $this->qb_limit);
+		$sql = $this->_delete($table);
 		if ($reset_data)
 		{
 			$this->_reset_write();
@@ -1915,21 +1882,12 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		return 'DELETE FROM '.$table
-			.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '')
-			.($limit ? ' LIMIT '.(int) $limit : '');
+		return 'DELETE FROM '.$table.$this->_compile_wh('qb_where')
+			.($this->qb_limit ? ' LIMIT '.$this->qb_limit : '');
 	}
 
 	// --------------------------------------------------------------------
@@ -2018,8 +1976,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * Compile the SELECT statement
 	 *
 	 * Generates a query string based on which functions were used.
-	 * Should not be called directly.  The get() function calls it.
+	 * Should not be called directly.
 	 *
+	 * @param	bool	$select_override = FALSE
 	 * @return	string
 	 */
 	protected function _compile_select($select_override = FALSE)
@@ -2058,7 +2017,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		// Write the "FROM" portion of the query
 		if (count($this->qb_from) > 0)
 		{
-			$sql .= "\nFROM ".$this->_from_tables($this->qb_from);
+			$sql .= "\nFROM ".$this->_from_tables();
 		}
 
 		// Write the "JOIN" portion of the query
@@ -2067,50 +2026,156 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$sql .= "\n".implode("\n", $this->qb_join);
 		}
 
-		// Write the "WHERE" portion of the query
-		if (count($this->qb_where) > 0 OR count($this->qb_like) > 0)
+		$sql .= $this->_compile_wh('qb_where')
+			.$this->_compile_group_by()
+			.$this->_compile_wh('qb_having')
+			.$this->_compile_order_by(); // ORDER BY
+
+		// LIMIT
+		if ($this->qb_limit)
 		{
-			$sql .= "\nWHERE ";
+			return $this->_limit($sql."\n");
 		}
 
-		$sql .= implode("\n", $this->qb_where);
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
 
-		// Write the "LIKE" portion of the query
-		if (count($this->qb_like) > 0)
+	/**
+	 * Compile WHERE, HAVING statements
+	 *
+	 * Escapes identifiers in WHERE and HAVING statements at execution time.
+	 *
+	 * Required so that aliases are tracked properly, regardless of wether
+	 * where(), or_where(), having(), or_having are called prior to from(),
+	 * join() and dbprefix is added only if needed.
+	 *
+	 * @param	string	'qb_where' or 'qb_having'
+	 * @return	string	SQL statement
+	 */
+	protected function _compile_wh($qb_key)
+	{
+		if (count($this->$qb_key) > 0)
 		{
-			if (count($this->qb_where) > 0)
+			for ($i = 0, $c = count($this->$qb_key); $i < $c; $i++)
 			{
-				$sql .= "\nAND ";
+				if ($this->{$qb_key}[$i]['escape'] === FALSE)
+				{
+					$this->{$qb_key}[$i] = $this->{$qb_key}[$i]['condition'];
+					continue;
+				}
+
+				// Split multiple conditions
+				$conditions = preg_split(
+					'/(\s*AND\s+|\s*OR\s+)/i',
+					$this->{$qb_key}[$i]['condition'],
+					-1,
+					PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY
+				);
+
+				for ($ci = 0, $cc = count($conditions); $ci < $cc; $ci++)
+				{
+					if (($op = $this->_get_operator($conditions[$ci])) === FALSE
+						OR ! preg_match('/^(\(?)(.*)('.preg_quote($op).')\s*(.*(?<!\)))?(\)?)$/i', $conditions[$ci], $matches))
+					{
+						continue;
+					}
+
+					// $matches = array(
+					//	0 => '(test <= foo)',	/* the whole thing */
+					//	1 => '(',		/* optional */
+					//	2 => 'test',		/* the field name */
+					//	3 => ' <= ',		/* $op */
+					//	4 => 'foo',		/* optional, if $op is e.g. 'IS NULL' */
+					//	5 => ')'		/* optional */
+					// );
+
+					if ( ! empty($matches[4]))
+					{
+						$this->_is_literal($matches[4]) OR $matches[4] = $this->protect_identifiers(trim($matches[4]));
+						$matches[4] = ' '.$matches[4];
+					}
+
+					$conditions[$ci] = $matches[1].$this->protect_identifiers(trim($matches[2]))
+						.' '.trim($matches[3]).$matches[4].$matches[5];
+				}
+
+				$this->{$qb_key}[$i] = implode('', $conditions);
 			}
 
-			$sql .= implode("\n", $this->qb_like);
+			return ($qb_key === 'qb_having' ? "\nHAVING " : "\nWHERE ")
+				.implode("\n", $this->$qb_key);
 		}
 
-		// Write the "GROUP BY" portion of the query
+		return '';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Compile GROUP BY
+	 *
+	 * Escapes identifiers in GROUP BY statements at execution time.
+	 *
+	 * Required so that aliases are tracked properly, regardless of wether
+	 * group_by() is called prior to from(), join() and dbprefix is added
+	 * only if needed.
+	 *
+	 * @return	string	SQL statement
+	 */
+	protected function _compile_group_by()
+	{
 		if (count($this->qb_groupby) > 0)
 		{
-			$sql .= "\nGROUP BY ".implode(', ', $this->qb_groupby);
-		}
+			for ($i = 0, $c = count($this->qb_groupby); $i < $c; $i++)
+			{
+				$this->qb_groupby[$i] = ($this->qb_groupby[$i]['escape'] === FALSE OR $this->_is_literal($this->qb_groupby[$i]['field']))
+					? $this->qb_groupby[$i]['field']
+					: $this->protect_identifiers($this->qb_groupby[$i]['field']);
+			}
 
-		// Write the "HAVING" portion of the query
-		if (count($this->qb_having) > 0)
-		{
-			$sql .= "\nHAVING ".implode("\n", $this->qb_having);
+			return "\nGROUP BY ".implode(', ', $this->qb_groupby);
 		}
 
-		// Write the "ORDER BY" portion of the query
-		if (count($this->qb_orderby) > 0)
+		return '';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Compile ORDER BY
+	 *
+	 * Escapes identifiers in ORDER BY statements at execution time.
+	 *
+	 * Required so that aliases are tracked properly, regardless of wether
+	 * order_by() is called prior to from(), join() and dbprefix is added
+	 * only if needed.
+	 *
+	 * @return	string	SQL statement
+	 */
+	protected function _compile_order_by()
+	{
+		if (is_array($this->qb_orderby) && count($this->qb_orderby) > 0)
 		{
-			$sql .= "\nORDER BY ".implode(', ', $this->qb_orderby);
-		}
+			for ($i = 0, $c = count($this->qb_orderby); $i < $c; $i++)
+			{
+				if ($this->qb_orderby[$i]['escape'] !== FALSE && ! $this->_is_literal($this->qb_orderby[$i]['field']))
+				{
+					$this->qb_orderby[$i]['field'] = $this->protect_identifiers($this->qb_orderby[$i]['field']);
+				}
+
+				$this->qb_orderby[$i] = $this->qb_orderby[$i]['field'].$this->qb_orderby[$i]['direction'];
+			}
 
-		// Write the "LIMIT" portion of the query
-		if (is_numeric($this->qb_limit))
+			return $this->qb_orderby = "\nORDER BY ".implode(', ', $this->qb_orderby);
+		}
+		elseif (is_string($this->qb_orderby))
 		{
-			return $this->_limit($sql."\n", $this->qb_limit, $this->qb_offset);
+			return $this->qb_orderby;
 		}
 
-		return $sql;
+		return '';
 	}
 
 	// --------------------------------------------------------------------
@@ -2277,6 +2342,36 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Is literal
+	 *
+	 * Determines if a string represents a literal value or a field name
+	 *
+	 * @param	string
+	 * @return	bool
+	 */
+	protected function _is_literal($str)
+	{
+		$str = trim($str);
+
+		if (empty($str))
+		{
+			return TRUE;
+		}
+
+		static $_str;
+
+		if (empty($_str))
+		{
+			$_str = ($this->_escape_char !== '"')
+				? array('"', "'") : array("'");
+		}
+
+		return (ctype_digit($str) OR in_array($str[0], $_str, TRUE));
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Reset Query Builder values.
 	 *
 	 * Publicly-visible method to reset the QB values.
@@ -2322,11 +2417,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 					'qb_from'		=> array(),
 					'qb_join'		=> array(),
 					'qb_where'		=> array(),
-					'qb_like'		=> array(),
 					'qb_groupby'		=> array(),
 					'qb_having'		=> array(),
 					'qb_orderby'		=> array(),
-					'qb_wherein'		=> array(),
 					'qb_aliased_tables'	=> array(),
 					'qb_no_escape'		=> array(),
 					'qb_distinct'		=> FALSE,
@@ -2351,7 +2444,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			'qb_set'	=> array(),
 			'qb_from'	=> array(),
 			'qb_where'	=> array(),
-			'qb_like'	=> array(),
 			'qb_orderby'	=> array(),
 			'qb_keys'	=> array(),
 			'qb_limit'	=> FALSE
diff --git a/system/database/DB_result.php b/system/database/DB_result.php
index d44df6c02..76093f918 100644
--- a/system/database/DB_result.php
+++ b/system/database/DB_result.php
@@ -251,27 +251,24 @@ class CI_DB_result {
 	/**
 	 * Query result.  Acts as a wrapper function for the following functions.
 	 *
-	 * @param	string
-	 * @param	string	can be "object" or "array"
-	 * @return	mixed	either a result object or array
+	 * @param	mixed	$n = 0
+	 * @param	string	$type = 'object'	'object' or 'array'
+	 * @return	mixed
 	 */
 	public function row($n = 0, $type = 'object')
 	{
 		if ( ! is_numeric($n))
 		{
 			// We cache the row data for subsequent uses
-			if ( ! is_array($this->row_data))
-			{
-				$this->row_data = $this->row_array(0);
-			}
+			is_array($this->row_data) OR $this->row_data = $this->row_array(0);
 
-			// array_key_exists() instead of isset() to allow for MySQL NULL values
-			if (array_key_exists($n, $this->row_data))
+			// array_key_exists() instead of isset() to allow for NULL values
+			if (empty($this->row_data) OR ! array_key_exists($n, $this->row_data))
 			{
-				return $this->row_data[$n];
+				return NULL;
 			}
-			// reset the $n variable if the result was not achieved
-			$n = 0;
+
+			return $this->row_data[$n];
 		}
 
 		if ($type === 'object') return $this->row_object($n);
@@ -284,6 +281,8 @@ class CI_DB_result {
 	/**
 	 * Assigns an item into a particular column slot
 	 *
+	 * @param	mixed	$key
+	 * @param	mixed	$value
 	 * @return	void
 	 */
 	public function set_row($key, $value = NULL)
@@ -314,6 +313,8 @@ class CI_DB_result {
 	/**
 	 * Returns a single result row - custom object version
 	 *
+	 * @param	int	$n
+	 * @param	string	$type
 	 * @return	object
 	 */
 	public function custom_row_object($n, $type)
@@ -338,6 +339,7 @@ class CI_DB_result {
 	/**
 	 * Returns a single result row - object version
 	 *
+	 * @param	int	$n = 0
 	 * @return	object
 	 */
 	public function row_object($n = 0)
@@ -361,6 +363,7 @@ class CI_DB_result {
 	/**
 	 * Returns a single result row - array version
 	 *
+	 * @param	int	$n = 0
 	 * @return	array
 	 */
 	public function row_array($n = 0)
@@ -384,7 +387,8 @@ class CI_DB_result {
 	/**
 	 * Returns the "first" row
 	 *
-	 * @return	object
+	 * @param	string	$type = 'object'
+	 * @return	mixed
 	 */
 	public function first_row($type = 'object')
 	{
@@ -397,7 +401,8 @@ class CI_DB_result {
 	/**
 	 * Returns the "last" row
 	 *
-	 * @return	object
+	 * @param	string	$type = 'object'
+	 * @return	mixed
 	 */
 	public function last_row($type = 'object')
 	{
@@ -410,7 +415,8 @@ class CI_DB_result {
 	/**
 	 * Returns the "next" row
 	 *
-	 * @return	object
+	 * @param	string	$type = 'object'
+	 * @return	mixed
 	 */
 	public function next_row($type = 'object')
 	{
@@ -433,7 +439,8 @@ class CI_DB_result {
 	/**
 	 * Returns the "previous" row
 	 *
-	 * @return	object
+	 * @param	string	$type = 'object'
+	 * @return	mixed
 	 */
 	public function previous_row($type = 'object')
 	{
@@ -455,8 +462,8 @@ class CI_DB_result {
 	/**
 	 * Returns an unbuffered row and move pointer to next row
 	 *
-	 * @param	string	'array', 'object' or a custom class name
-	 * @return	mixed	either a result object or array
+	 * @param	string	$type = 'object'	'array', 'object' or a custom class name
+	 * @return	mixed
 	 */
 	public function unbuffered_row($type = 'object')
 	{
diff --git a/system/database/DB_utility.php b/system/database/DB_utility.php
index 6a3b40779..8078e2bf6 100644
--- a/system/database/DB_utility.php
+++ b/system/database/DB_utility.php
@@ -41,6 +41,11 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	protected $_optimize_table	= FALSE;
 	protected $_repair_table	= FALSE;
 
+	/**
+	 * Constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		// Assign the main database object to $this->db
@@ -275,6 +280,7 @@ abstract class CI_DB_utility extends CI_DB_forge {
 	/**
 	 * Database Backup
 	 *
+	 * @param	array	$params = array()
 	 * @return	void
 	 */
 	public function backup($params = array())
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index a3d0287f5..8e77d8396 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -45,15 +45,17 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// The character used for escaping - no need in CUBRID
 	protected $_escape_char = '`';
 
-	// clause and character used for LIKE escape sequences - not used in CUBRID
-	protected $_like_escape_str = '';
-	protected $_like_escape_chr = '';
-
 	protected $_random_keyword = ' RAND()'; // database specific random keyword
 
 	// CUBRID-specific properties
 	public $auto_commit = TRUE;
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array	$params
+	 * @return	void
+	 */
 	public function __construct($params)
 	{
 		parent::__construct($params);
@@ -72,6 +74,8 @@ class CI_DB_cubrid_driver extends CI_DB {
 		}
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
@@ -182,6 +186,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -396,10 +401,10 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -423,9 +428,29 @@ class CI_DB_cubrid_driver extends CI_DB {
 				.'ELSE '.$k.' END, ';
 		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN ('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * FROM tables
+	 *
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
+	 *
+	 * @return	string
+	 */
+	protected function _from_tables()
+	{
+		if ( ! empty($this->qb_join) && count($this->qb_from) > 1)
+		{
+			return '('.implode(', ', $this->qb_from).')';
+		}
+
+		return implode(', ', $this->qb_from);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/cubrid/cubrid_result.php b/system/database/drivers/cubrid/cubrid_result.php
index 4a06a2d39..360c50dc2 100644
--- a/system/database/drivers/cubrid/cubrid_result.php
+++ b/system/database/drivers/cubrid/cubrid_result.php
@@ -132,6 +132,7 @@ class CI_DB_cubrid_result extends CI_DB_result {
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
+	 * @param	int	$n = 0
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/ibase/ibase_driver.php b/system/database/drivers/ibase/ibase_driver.php
index c9027670d..c3be519bf 100644
--- a/system/database/drivers/ibase/ibase_driver.php
+++ b/system/database/drivers/ibase/ibase_driver.php
@@ -45,10 +45,6 @@ class CI_DB_ibase_driver extends CI_DB {
 	// The character used to escape with
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " ESCAPE '%s' ";
-	protected $_like_escape_chr = '!';
-
 	protected $_random_keyword = ' Random()'; // database specific random keyword
 
 	// Keeps track of the resource for the current transaction
@@ -120,6 +116,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -285,7 +282,10 @@ class CI_DB_ibase_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return $this->_limit('SELECT * FROM '.$this->protect_identifiers($table), 1, NULL);
+		$this->qb_limit = 1;
+		$sql = $this->_limit('SELECT * FROM '.$this->protect_identifiers($table));
+		$this->qb_limit = 0;
+		return $sql;
 	}
 
 	// --------------------------------------------------------------------
@@ -306,51 +306,18 @@ class CI_DB_ibase_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This public function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
 	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
-			.$where
-			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '');
+		$this->qb_limit = FALSE;
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -379,19 +346,12 @@ class CI_DB_ibase_driver extends CI_DB {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause (ignored)
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		return 'DELETE FROM '.$table.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '');
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -402,22 +362,20 @@ class CI_DB_ibase_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// Limit clause depends on if Interbase or Firebird
 		if (stripos($this->version(), 'firebird') !== FALSE)
 		{
-			$select = 'FIRST '. (int) $limit
-				.($offset ? ' SKIP '. (int) $offset : '');
+			$select = 'FIRST '.$this->qb_limit
+				.($this->qb_offset ? ' SKIP '.$this->qb_offset : '');
 		}
 		else
 		{
 			$select = 'ROWS '
-				.($offset ? (int) $offset.' TO '.($limit + $offset) : (int) $limit);
+				.($this->qb_offset ? $this->qb_offset.' TO '.($this->qb_limit + $this->qb_offset) : $this->qb_limit);
 		}
 
 		return preg_replace('`SELECT`i', 'SELECT '.$select, $sql);
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 1714704a8..2063dad90 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -45,21 +45,17 @@ class CI_DB_mssql_driver extends CI_DB {
 	// The character used for escaping
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " ESCAPE '%s' ";
-	protected $_like_escape_chr = '!';
-
 	protected $_random_keyword = ' NEWID()';
 
 	// MSSQL-specific properties
 	protected $_quoted_identifier = TRUE;
 
-	/*
+	/**
 	 * Constructor
 	 *
 	 * Appends the port number to the hostname, if needed.
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -156,6 +152,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -366,49 +363,19 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
 	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).' WHERE '.$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -437,23 +404,16 @@ class CI_DB_mssql_driver extends CI_DB {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
+		if ($this->qb_limit)
+		{
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+		}
 
-		return ($limit)
-			? 'WITH ci_delete AS (SELECT TOP '.$limit.' * FROM '.$table.$conditions.') DELETE FROM ci_delete'
-			: 'DELETE FROM '.$table.$conditions;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -464,33 +424,44 @@ class CI_DB_mssql_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		// As of SQL Server 2012 (11.0.*) OFFSET is supported
-		if (version_compare($this->version(), '11', '>='))
-		{
-			return $sql.' OFFSET '.(int) $offset.' ROWS FETCH NEXT '.(int) $limit.' ROWS ONLY';
-		}
-
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// As of SQL Server 2005 (9.0.*) ROW_NUMBER() is supported,
 		// however an ORDER BY clause is required for it to work
-		if (version_compare($this->version(), '9', '>=') && $offset && ! empty($this->qb_orderby))
+		if (version_compare($this->version(), '9', '>=') && $this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = $this->_compile_order_by();
 
 			// We have to strip the ORDER BY clause
-			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
+			$sql = trim(substr($sql, 0, strrpos($sql, $orderby)));
+
+			// Get the fields to select from our subquery, so that we can avoid CI_rownum appearing in the actual results
+			if (count($this->qb_select) === 0)
+			{
+				$select = '*'; // Inevitable
+			}
+			else
+			{
+				// Use only field names and their aliases, everything else is out of our scope.
+				$select = array();
+				$field_regexp = ($this->_quoted_identifier)
+					? '("[^\"]+")' : '(\[[^\]]+\])';
+				for ($i = 0, $c = count($this->qb_select); $i < $c; $i++)
+				{
+					$select[] = preg_match('/(?:\s|\.)'.$field_regexp.'$/i', $this->qb_select[$i], $m)
+						? $m[1] : $this->qb_select[$i];
+				}
+				$select = implode(', ', $select);
+			}
 
-			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
-				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
-				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+			return 'SELECT '.$select." FROM (\n\n"
+				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.trim($orderby).') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
+				."\n\n) ".$this->escape_identifiers('CI_subquery')
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
diff --git a/system/database/drivers/mssql/mssql_result.php b/system/database/drivers/mssql/mssql_result.php
index aeede3f4b..84d2814f1 100644
--- a/system/database/drivers/mssql/mssql_result.php
+++ b/system/database/drivers/mssql/mssql_result.php
@@ -133,6 +133,7 @@ class CI_DB_mssql_result extends CI_DB_result {
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
+	 * @param	int	$n = 0
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 29db90408..f82e775e6 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -41,14 +41,11 @@
 class CI_DB_mysql_driver extends CI_DB {
 
 	public $dbdriver = 'mysql';
+	public $compress = FALSE;
 
 	// The character used for escaping
 	protected $_escape_char = '`';
 
-	// clause and character used for LIKE escape sequences - not used in MySQL
-	protected $_like_escape_str = '';
-	protected $_like_escape_chr = '\\';
-
 	protected $_random_keyword = ' RAND()'; // database specific random keyword
 
 	/**
@@ -79,11 +76,21 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Non-persistent database connection
 	 *
+	 * @param	bool
 	 * @return	resource
 	 */
-	public function db_connect()
+	public function db_connect($persistent = FALSE)
 	{
-		return @mysql_connect($this->hostname, $this->username, $this->password, TRUE);
+		$client_flags = ($this->compress === FALSE) ? 0 : MYSQL_CLIENT_COMPRESS;
+
+		if ($this->encrypt === TRUE)
+		{
+			$client_flags = $client_flags | MYSQL_CLIENT_SSL;
+		}
+
+		return ($persistent === TRUE)
+			? @mysql_pconnect($this->hostname, $this->username, $this->password, $client_flags)
+			: @mysql_connect($this->hostname, $this->username, $this->password, TRUE, $client_flags);
 	}
 
 	// --------------------------------------------------------------------
@@ -95,7 +102,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	public function db_pconnect()
 	{
-		return @mysql_pconnect($this->hostname, $this->username, $this->password);
+		return $this->db_connect(TRUE);
 	}
 
 	// --------------------------------------------------------------------
@@ -207,6 +214,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -420,10 +428,10 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -447,9 +455,29 @@ class CI_DB_mysql_driver extends CI_DB {
 				.'ELSE '.$k.' END, ';
 		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * FROM tables
+	 *
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
+	 *
+	 * @return	string
+	 */
+	protected function _from_tables()
+	{
+		if ( ! empty($this->qb_join) && count($this->qb_from) > 1)
+		{
+			return '('.implode(', ', $this->qb_from).')';
+		}
+
+		return implode(', ', $this->qb_from);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysql/mysql_result.php b/system/database/drivers/mysql/mysql_result.php
index 7fbb65496..b3f669e40 100644
--- a/system/database/drivers/mysql/mysql_result.php
+++ b/system/database/drivers/mysql/mysql_result.php
@@ -146,6 +146,7 @@ class CI_DB_mysql_result extends CI_DB_result {
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
+	 * @param	int	$n = 0
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index be61aab20..6c4f87513 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -41,14 +41,11 @@
 class CI_DB_mysqli_driver extends CI_DB {
 
 	public $dbdriver = 'mysqli';
+	public $compress = FALSE;
 
 	// The character used for escaping
 	protected $_escape_char = '`';
 
-	// clause and character used for LIKE escape sequences - not used in MySQL
-	protected $_like_escape_str = '';
-	protected $_like_escape_chr = '\\';
-
 	protected $_random_keyword = ' RAND()'; // database specific random keyword
 
 	/**
@@ -61,13 +58,21 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Non-persistent database connection
 	 *
+	 * @param	bool
 	 * @return	object
+	 * @todo	SSL support
 	 */
-	public function db_connect()
+	public function db_connect($persistent = FALSE)
 	{
-		return empty($this->port)
-			? @new mysqli($this->hostname, $this->username, $this->password, $this->database)
-			: @new mysqli($this->hostname, $this->username, $this->password, $this->database, $this->port);
+		// Persistent connection support was added in PHP 5.3.0
+		$hostname = ($persistent === TRUE && is_php('5.3'))
+			? 'p:'.$this->hostname : $this->hostname;
+		$port = empty($this->port) ? NULL : $this->port;
+		$client_flags = ($this->compress === TRUE) ? MYSQLI_CLIENT_COMPRESS : 0;
+		$mysqli = mysqli_init();
+
+		return @$mysqli->real_connect($hostname, $this->username, $this->password, $this->database, $port, NULL, $client_flags)
+			? $mysqli : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -79,15 +84,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function db_pconnect()
 	{
-		// Persistent connection support was added in PHP 5.3.0
-		if ( ! is_php('5.3'))
-		{
-			return $this->db_connect();
-		}
-
-		return empty($this->port)
-			? @new mysqli('p:'.$this->hostname, $this->username, $this->password, $this->database)
-			: @new mysqli('p:'.$this->hostname, $this->username, $this->password, $this->database, $this->port);
+		return $this->db_connect(TRUE);
 	}
 
 	// --------------------------------------------------------------------
@@ -199,6 +196,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -400,6 +398,14 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	public function error()
 	{
+		if ( ! empty($this->conn_id->connect_errno))
+		{
+			return array(
+				'code' => $this->conn_id->connect_errno,
+				'message' => is_php('5.2.9') ? $this->conn_id->connect_error : mysqli_connect_error()
+			);
+		}
+
 		return array('code' => $this->conn_id->errno, 'message' => $this->conn_id->error);
 	}
 
@@ -412,10 +418,10 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -439,11 +445,29 @@ class CI_DB_mysqli_driver extends CI_DB {
 				.'ELSE '.$k.' END, ';
 		}
 
-		$where = ($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * FROM tables
+	 *
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
+	 *
+	 * @return	string
+	 */
+	protected function _from_tables()
+	{
+		if ( ! empty($this->qb_join) && count($this->qb_from) > 1)
+		{
+			return '('.implode(', ', $this->qb_from).')';
+		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN('.implode(',', $ids).')';
+		return implode(', ', $this->qb_from);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysqli/mysqli_result.php b/system/database/drivers/mysqli/mysqli_result.php
index c1ec4da76..f036302bb 100644
--- a/system/database/drivers/mysqli/mysqli_result.php
+++ b/system/database/drivers/mysqli/mysqli_result.php
@@ -132,6 +132,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
+	 * @param	int	$n = 0
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 691247fee..81d73d073 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -54,10 +54,6 @@ class CI_DB_oci8_driver extends CI_DB {
 	// The character used for excaping
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " ESCAPE '%s' ";
-	protected $_like_escape_chr = '!';
-
 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is
@@ -79,6 +75,12 @@ class CI_DB_oci8_driver extends CI_DB {
 	// throw off num_fields later
 	public $limit_used;
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array	$params
+	 * @return	void
+	 */
 	public function __construct($params)
 	{
 		parent::__construct($params);
@@ -547,22 +549,6 @@ class CI_DB_oci8_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Insert_batch statement
 	 *
 	 * Generates a platform-specific insert string from the supplied data
@@ -611,20 +597,17 @@ class CI_DB_oci8_driver extends CI_DB {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-		empty($limit) OR $conditions[] = 'rownum <= '.$limit;
+		if ($this->qb_limit)
+		{
+			$this->where('rownum <= ',$this->qb_limit, FALSE);
+			$this->qb_limit = FALSE;
+		}
 
-		return 'DELETE FROM '.$table.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '');
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -635,15 +618,13 @@ class CI_DB_oci8_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		$this->limit_used = TRUE;
-		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($offset + $limit + 1).')'
-			.($offset ? ' WHERE rnum >= '.($offset + 1): '');
+		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
+			.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1): '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index 8f0a474b0..063a04b98 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -45,12 +45,16 @@ class CI_DB_odbc_driver extends CI_DB {
 	// the character used to excape - not necessary for ODBC
 	protected $_escape_char = '';
 
-	// clause and character used for LIKE escape sequences
 	protected $_like_escape_str = " {escape '%s'} ";
-	protected $_like_escape_chr = '!';
 
 	protected $_random_keyword;
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array	$params
+	 * @return	void
+	 */
 	public function __construct($params)
 	{
 		parent::__construct($params);
@@ -64,6 +68,8 @@ class CI_DB_odbc_driver extends CI_DB {
 		}
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
@@ -104,6 +110,7 @@ class CI_DB_odbc_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -291,17 +298,19 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
+	 * Update statement
 	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
+	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @param	array
+	 * @param	string	the table name
+	 * @param	array	the update data
 	 * @return	string
-	 */
-	protected function _from_tables($tables)
+         */
+	protected function _update($table, $values)
 	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -325,6 +334,22 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Delete statement
+	 *
+	 * Generates a platform-specific delete string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @return	string
+	 */
+	protected function _delete($table)
+	{
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index 705b16560..32a9e7509 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -45,10 +45,6 @@ class CI_DB_pdo_driver extends CI_DB {
 	// The character used to escaping
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " ESCAPE '%s' ";
-	protected $_like_escape_chr = '!';
-
 	protected $_random_keyword;
 
 	public $trans_enabled = FALSE;
@@ -61,7 +57,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * Validates the DSN string and/or detects the subdriver
 	 *
-	 * @param	array
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -187,6 +183,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -360,14 +357,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
-		$where = ($where !== '' && count($where) >=1) ? implode(' ', $where).' AND ' : '';
-
 		foreach ($values as $key => $val)
 		{
 			$ids[] = $val[$index];
@@ -381,9 +376,7 @@ class CI_DB_pdo_driver extends CI_DB {
 			}
 		}
 
-		$sql   = 'UPDATE '.$table.' SET ';
 		$cases = '';
-
 		foreach ($final as $k => $v)
 		{
 			$cases .= $k.' = CASE '."\n";
@@ -396,10 +389,9 @@ class CI_DB_pdo_driver extends CI_DB {
 			$cases .= 'ELSE '.$k.' END, ';
 		}
 
-		$sql .= substr($cases, 0, -2);
-		$sql .= ' WHERE '.$where.$index.' IN ('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
 
-		return $sql;
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
index e287f5c63..438d312a1 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
@@ -130,49 +130,19 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
          */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -183,21 +153,12 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause (ignored)
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
-
-		return 'DELETE FROM '.$table.$conditions;
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -208,13 +169,11 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
+		return $sql.' LIMIT '.$this->qb_limit.($this->qb_offset ? ' OFFSET '.$this->qb_offset : '');
 	}
 
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
index 05eeacfe6..d2a484d9e 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
@@ -44,10 +44,6 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 
 	protected $_escape_char = '`';
 
-	// clause and character used for LIKE escape sequences - not used in CUBRID
-	protected $_like_escape_str = '';
-	protected $_like_escape_chr = '\\';
-
 	protected $_random_keyword = ' RAND()';
 
 	/**
@@ -133,10 +129,10 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -160,9 +156,9 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 				.'ELSE '.$k.' END), ';
 		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
 
 	// --------------------------------------------------------------------
@@ -183,6 +179,26 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 		return 'TRUNCATE '.$table;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * FROM tables
+	 *
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
+	 *
+	 * @return	string
+	 */
+	protected function _from_tables()
+	{
+		if ( ! empty($this->qb_join) && count($this->qb_from) > 1)
+		{
+			return '('.implode(', ', $this->qb_from).')';
+		}
+
+		return implode(', ', $this->qb_from);
+	}
+
 }
 
 /* End of file pdo_cubrid_driver.php */
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index 7060c9eb9..785b2795c 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -153,49 +153,19 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
          */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -206,23 +176,16 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
+		if ($this->qb_limit)
+		{
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+		}
 
-		return ($limit)
-			? 'WITH ci_delete AS (SELECT TOP '.$limit.' * FROM '.$table.$conditions.') DELETE FROM ci_delete'
-			: 'DELETE FROM '.$table.$conditions;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -233,27 +196,44 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// As of SQL Server 2005 (9.0.*) ROW_NUMBER() is supported,
 		// however an ORDER BY clause is required for it to work
-		if (version_compare($this->version(), '9', '>=') && $offset && ! empty($this->qb_orderby))
+		if (version_compare($this->version(), '9', '>=') && $this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = $this->_compile_order_by();
 
 			// We have to strip the ORDER BY clause
-			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
+			$sql = trim(substr($sql, 0, strrpos($sql, $orderby)));
+
+			// Get the fields to select from our subquery, so that we can avoid CI_rownum appearing in the actual results
+			if (count($this->qb_select) === 0)
+			{
+				$select = '*'; // Inevitable
+			}
+			else
+			{
+				// Use only field names and their aliases, everything else is out of our scope.
+				$select = array();
+				$field_regexp = ($this->_quoted_identifier)
+					? '("[^\"]+")' : '(\[[^\]]+\])';
+				for ($i = 0, $c = count($this->qb_select); $i < $c; $i++)
+				{
+					$select[] = preg_match('/(?:\s|\.)'.$field_regexp.'$/i', $this->qb_select[$i], $m)
+						? $m[1] : $this->qb_select[$i];
+				}
+				$select = implode(', ', $select);
+			}
 
-			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
-				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
-				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+			return 'SELECT '.$select." FROM (\n\n"
+				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.trim($orderby).') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
+				."\n\n) ".$this->escape_identifiers('CI_subquery')
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
@@ -262,4 +242,4 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 }
 
 /* End of file pdo_dblib_driver.php */
-/* Location: ./system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index c074a9a78..32d1f219a 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -139,51 +139,18 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return 	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
 	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
-			.$where
-			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '');
+		$this->qb_limit = FALSE;
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -212,19 +179,12 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause (ignored)
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		return 'DELETE FROM '.$table.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '');
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -235,22 +195,20 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// Limit clause depends on if Interbase or Firebird
 		if (stripos($this->version(), 'firebird') !== FALSE)
 		{
-			$select = 'FIRST '. (int) $limit
-				.($offset > 0 ? ' SKIP '. (int) $offset : '');
+			$select = 'FIRST '.$this->qb_limit
+				.($this->qb_offset > 0 ? ' SKIP '.$this->qb_offset : '');
 		}
 		else
 		{
 			$select = 'ROWS '
-				.($offset > 0 ? (int) $offset.' TO '.($limit + $offset) : (int) $limit);
+				.($this->qb_offset > 0 ? $this->qb_offset.' TO '.($this->qb_limit + $this->qb_offset) : $this->qb_limit);
 		}
 
 		return preg_replace('`SELECT`i', 'SELECT '.$select, $sql);
diff --git a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
index 832c03c96..22a5f928c 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
@@ -165,49 +165,19 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
          */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -218,21 +188,12 @@ class CI_DB_pdo_ibm_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause (ignored)
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
-
-		return 'DELETE FROM '.$table.$conditions;
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
index a3efc63dc..8dd430184 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
@@ -159,49 +159,19 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
          */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -230,21 +200,12 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause (ignored)
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
-
-		return 'DELETE FROM '.$table.$conditions;
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -255,13 +216,11 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		$select = 'SELECT '.($offset ? 'SKIP '.$offset : '').'FIRST '.$limit.' ';
+		$select = 'SELECT '.($this->qb_offset ? 'SKIP '.$this->qb_offset : '').'FIRST '.$this->qb_limit.' ';
 		return preg_replace('/^(SELECT\s)/i', $select, $sql, 1);
 	}
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index 78afe246c..0fb5d8f12 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -41,13 +41,10 @@
 class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 
 	public $subdriver = 'mysql';
+	public $compress = FALSE;
 
 	protected $_escape_char = '`';
 
-	// clause and character used for LIKE escape sequences - not used in MySQL
-	protected $_like_escape_str = '';
-	protected $_like_escape_chr = '\\';
-
 	protected $_random_keyword = ' RAND()';
 
 	/**
@@ -83,6 +80,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * @param	bool
 	 * @return	object
+	 * @todo	SSL support
 	 */
 	public function db_connect($persistent = FALSE)
 	{
@@ -97,6 +95,11 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 				.(empty($this->dbcollat) ? '' : ' COLLATE '.$this->dbcollat);
 		}
 
+		if ($this->compress === TRUE)
+		{
+			$this->options[PDO::MYSQL_ATTR_COMPRESS] = TRUE;
+		}
+
 		return parent::db_connect($persistent);
 	}
 
@@ -161,10 +164,10 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -188,9 +191,9 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 				.'ELSE '.$k.' END), ';
 		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
 
 	// --------------------------------------------------------------------
@@ -211,6 +214,26 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 		return 'TRUNCATE '.$table;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * FROM tables
+	 *
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
+	 *
+	 * @return	string
+	 */
+	protected function _from_tables()
+	{
+		if ( ! empty($this->qb_join) && count($this->qb_from) > 1)
+		{
+			return '('.implode(', ', $this->qb_from).')';
+		}
+
+		return implode(', ', $this->qb_from);
+	}
+
 }
 
 /* End of file pdo_mysql_driver.php */
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
index 56ec1bce1..b03218fad 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
@@ -146,22 +146,6 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Insert_batch statement
 	 *
 	 * @param	string	the table name
@@ -190,20 +174,17 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-		empty($limit) OR $conditions[] = 'rownum <= '.$limit;
+		if ($this->qb_limit)
+		{
+			$this->where('rownum <= ',$this->qb_limit, FALSE);
+			$this->qb_limit = FALSE;
+		}
 
-		return 'DELETE FROM '.$table.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '');
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -214,14 +195,12 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($offset + $limit + 1).')'
-			.($offset ? ' WHERE rnum >= '.($offset + 1): '');
+		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
+			.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1): '');
 	}
 
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
index 392754ff7..5944d55f4 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
@@ -46,7 +46,6 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	protected $_escape_char = '';
 
 	// clause and character used for LIKE escape sequences
-	protected $_like_escape_chr = '!';
 	protected $_like_escape_str = " {escape '%s'} ";
 
 	protected $_random_keyword = ' RAND()';
@@ -157,49 +156,19 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
          */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -228,21 +197,12 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
-
-		return 'DELETE FROM '.$table.$conditions;
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -253,13 +213,11 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
+		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$this->qb_limit.' ', $sql);
 	}
 
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
index 9a476f143..74d56e6b8 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
@@ -142,49 +142,19 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
          */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -196,10 +166,10 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -218,14 +188,14 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 		$cases = '';
 		foreach ($final as $k => $v)
 		{
-			$cases .= $k.' = (CASE '.$k."\n"
+			$cases .= $k.' = (CASE '.$index."\n"
 				.implode("\n", $v)."\n"
 				.'ELSE '.$k.' END), ';
 		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
 
 	// --------------------------------------------------------------------
@@ -236,19 +206,12 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause (ignored)
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		return 'DELETE FROM '.$table.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '');
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -259,29 +222,31 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
+		return $sql.' LIMIT '.$this->qb_limit.($this->qb_offset ? ' OFFSET '.$this->qb_offset : '');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where
+	 * WHERE, HAVING
 	 *
-	 * Called by where() or or_where()
+	 * Called by where(), or_where(), having(), or_having()
 	 *
+	 * @param	string	'qb_where' or 'qb_having'
 	 * @param	mixed
 	 * @param	mixed
 	 * @param	string
+	 * @param	bool
 	 * @return	object
 	 */
-	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
+	protected function _wh($qb_key, $key, $value = NULL, $type = 'AND ', $escape = NULL)
 	{
+		$qb_cache_key = ($qb_key === 'qb_having') ? 'qb_cache_having' : 'qb_cache_where';
+
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
@@ -292,14 +257,10 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+			$prefix = (count($this->$qb_key) === 0 && count($this->$qb_cache_key) === 0)
 				? $this->_group_get_type('')
 				: $this->_group_get_type($type);
 
-			$k = (($op = $this->_get_operator($k)) !== FALSE)
-				? $this->protect_identifiers(substr($k, 0, strpos($k, $op)), FALSE, $escape).strstr($k, $op)
-				: $this->protect_identifiers($k, FALSE, $escape);
-
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
 				// value appears not to have been set, assign the test to IS NULL
@@ -308,13 +269,13 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 
 			if ( ! is_null($v))
 			{
-				if ($escape === TRUE)
+				if (is_bool($v))
 				{
-					$v = ' '.$this->escape($v);
+					$v = ' '.($v ? 'TRUE' : 'FALSE');
 				}
-				elseif (is_bool($v))
+				elseif ($escape === TRUE)
 				{
-					$v = ($v ? ' TRUE' : ' FALSE');
+					$v = ' '.(is_int($v) ? $v : $this->escape($v));
 				}
 
 				if ( ! $this->_has_operator($k))
@@ -323,11 +284,11 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 				}
 			}
 
-			$this->qb_where[] = $prefix.$k.$v;
+			$this->{$qb_key}[] = array('condition' => $prefix.$k.$v, 'escape' => $escape);
 			if ($this->qb_caching === TRUE)
 			{
-				$this->qb_cache_where[] = $prefix.$k.$v;
-				$this->qb_cache_exists[] = 'where';
+				$this->{$qb_cache_key}[] = array('condition' => $prefix.$k.$v, 'escape' => $escape);
+				$this->qb_cache_exists[] = substr($qb_key, 3);
 			}
 
 		}
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index f125b8f50..33bd7bea5 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -78,9 +78,9 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 				$this->dsn .= ';ConnectionPooling='.$this->ConnectionPooling;
 			}
 
-			if (isset($this->Encrypt))
+			if ($this->encrypt === TRUE)
 			{
-				$this->dsn .= ';Encrypt='.$this->Encrypt;
+				$this->dsn .= ';Encrypt=1';
 			}
 
 			if (isset($this->TraceOn))
@@ -182,49 +182,19 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
          */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -235,23 +205,16 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
+		if ($this->qb_limit)
+		{
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+		}
 
-		return ($limit)
-			? 'WITH ci_delete AS (SELECT TOP '.$limit.' * FROM '.$table.$conditions.') DELETE FROM ci_delete'
-			: 'DELETE FROM '.$table.$conditions;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -262,32 +225,49 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// As of SQL Server 2012 (11.0.*) OFFSET is supported
 		if (version_compare($this->version(), '11', '>='))
 		{
-			return $sql.' OFFSET '.(int) $offset.' ROWS FETCH NEXT '.(int) $limit.' ROWS ONLY';
+			return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
 		}
 
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// An ORDER BY clause is required for ROW_NUMBER() to work
-		if ($offset && ! empty($this->qb_orderby))
+		if ($this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = $this->_compile_order_by();
 
 			// We have to strip the ORDER BY clause
-			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
+			$sql = trim(substr($sql, 0, strrpos($sql, $orderby)));
+
+			// Get the fields to select from our subquery, so that we can avoid CI_rownum appearing in the actual results
+			if (count($this->qb_select) === 0)
+			{
+				$select = '*'; // Inevitable
+			}
+			else
+			{
+				// Use only field names and their aliases, everything else is out of our scope.
+				$select = array();
+				$field_regexp = ($this->_quoted_identifier)
+					? '("[^\"]+")' : '(\[[^\]]+\])';
+				for ($i = 0, $c = count($this->qb_select); $i < $c; $i++)
+				{
+					$select[] = preg_match('/(?:\s|\.)'.$field_regexp.'$/i', $this->qb_select[$i], $m)
+						? $m[1] : $this->qb_select[$i];
+				}
+				$select = implode(', ', $select);
+			}
 
-			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
-				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
-				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+			return 'SELECT '.$select." FROM (\n\n"
+				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.trim($orderby).') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
+				."\n\n) ".$this->escape_identifiers('CI_subquery')
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
@@ -296,4 +276,4 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 }
 
 /* End of file pdo_sqlsrv_driver.php */
-/* Location: ./system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 031740851..1b9474920 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -44,10 +44,6 @@ class CI_DB_postgre_driver extends CI_DB {
 
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " ESCAPE '%s' ";
-	protected $_like_escape_chr = '!';
-
 	protected $_random_keyword = ' RANDOM()'; // database specific random keyword
 
 	/**
@@ -55,6 +51,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Creates a DSN string to be used for db_connect() and db_pconnect()
 	 *
+	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
@@ -132,7 +129,15 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public function db_pconnect()
 	{
-		return @pg_pconnect($this->dsn);
+		$conn = @pg_pconnect($this->dsn);
+		if ($conn && pg_connection_status($conn) === PGSQL_CONNECTION_BAD)
+		{
+			if (pg_ping($conn) === FALSE)
+			{
+				return FALSE;
+			}
+		}
+		return $conn;
 	}
 
 	// --------------------------------------------------------------------
@@ -453,49 +458,19 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
 	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -507,10 +482,10 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	the where key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -534,9 +509,9 @@ class CI_DB_postgre_driver extends CI_DB {
 				.'ELSE '.$k.' END), ';
 		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where !== '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
 
 	// --------------------------------------------------------------------
@@ -547,19 +522,12 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause (ignored)
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		return 'DELETE FROM '.$table.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '');
+		$this->qb_limit = FALSE;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -570,30 +538,31 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
+		return $sql.' LIMIT '.$this->qb_limit.($this->qb_offset ? ' OFFSET '.$this->qb_offset : '');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Where
+	 * WHERE, HAVING
 	 *
-	 * Called by where() or or_where()
+	 * Called by where(), or_where(), having(), or_having()
 	 *
+	 * @param	string	'qb_where' or 'qb_having'
 	 * @param	mixed
 	 * @param	mixed
 	 * @param	string
-	 * @param	mixed
+	 * @param	bool
 	 * @return	object
 	 */
-	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
+	protected function _wh($qb_key, $key, $value = NULL, $type = 'AND ', $escape = NULL)
 	{
+		$qb_cache_key = ($qb_key === 'qb_having') ? 'qb_cache_having' : 'qb_cache_where';
+
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
@@ -604,17 +573,10 @@ class CI_DB_postgre_driver extends CI_DB {
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+			$prefix = (count($this->$qb_key) === 0 && count($this->$qb_cache_key) === 0)
 				? $this->_group_get_type('')
 				: $this->_group_get_type($type);
 
-			if ($escape === TRUE)
-			{
-				$k = (($op = $this->_get_operator($k)) !== FALSE)
-					? $this->escape_identifiers(trim(substr($k, 0, strpos($k, $op)))).' '.strstr($k, $op)
-					: $this->escape_identifiers(trim($k));
-			}
-
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
 				// value appears not to have been set, assign the test to IS NULL
@@ -623,13 +585,13 @@ class CI_DB_postgre_driver extends CI_DB {
 
 			if ( ! is_null($v))
 			{
-				if ($escape === TRUE)
+				if (is_bool($v))
 				{
-					$v = ' '.$this->escape($v);
+					$v = ' '.($v ? 'TRUE' : 'FALSE');
 				}
-				elseif (is_bool($v))
+				elseif ($escape === TRUE)
 				{
-					$v = ($v ? ' TRUE' : ' FALSE');
+					$v = ' '.(is_int($v) ? $v : $this->escape($v));
 				}
 
 				if ( ! $this->_has_operator($k))
@@ -638,11 +600,11 @@ class CI_DB_postgre_driver extends CI_DB {
 				}
 			}
 
-			$this->qb_where[] = $prefix.$k.$v;
+			$this->{$qb_key}[] = array('condition' => $prefix.$k.$v, 'escape' => $escape);
 			if ($this->qb_caching === TRUE)
 			{
-				$this->qb_cache_where[] = $prefix.$k.$v;
-				$this->qb_cache_exists[] = 'where';
+				$this->{$qb_cache_key}[] = array('condition' => $prefix.$k.$v, 'escape' => $escape);
+				$this->qb_cache_exists[] = substr($qb_key, 3);
 			}
 
 		}
diff --git a/system/database/drivers/postgre/postgre_forge.php b/system/database/drivers/postgre/postgre_forge.php
index c434e9510..1164d9bb3 100644
--- a/system/database/drivers/postgre/postgre_forge.php
+++ b/system/database/drivers/postgre/postgre_forge.php
@@ -39,7 +39,8 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 	/**
 	 * Process Fields
 	 *
-	 * @param	mixed	the fields
+	 * @param	mixed	$fields
+	 * @param	array	$primary_keys = array()
 	 * @return	string
 	 */
 	protected function _process_fields($fields, $primary_keys = array())
@@ -190,13 +191,10 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 	 * Generates a platform-specific query so that a table can be altered
 	 * Called by add_column(), drop_column(), and column_alter(),
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	string	the table name
-	 * @param	string	the column definition
-	 * @param	string	the default value
-	 * @param	bool	should 'NOT NULL' be added
-	 * @param	string	the field after which we should add the new field
+	 * @param	string	$alter_type	the ALTER type (ADD, DROP, CHANGE)
+	 * @param	string	$table		the table name
+	 * @param	string	$fields		the column definition
+	 * @param	string	$after_field = ''
 	 * @return	string
 	 */
 	protected function _alter_table($alter_type, $table, $fields, $after_field = '')
diff --git a/system/database/drivers/postgre/postgre_result.php b/system/database/drivers/postgre/postgre_result.php
index eb9d647e7..458ae869c 100644
--- a/system/database/drivers/postgre/postgre_result.php
+++ b/system/database/drivers/postgre/postgre_result.php
@@ -131,6 +131,7 @@ class CI_DB_postgre_result extends CI_DB_result {
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
+	 * @param	int	$n = 0
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 19824dbbf..2fd39346f 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -45,10 +45,6 @@ class CI_DB_sqlite_driver extends CI_DB {
 	// The character used to escape with - not needed for SQLite
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " ESCAPE '%s' ";
-	protected $_like_escape_chr = '!';
-
 	protected $_random_keyword = ' Random()'; // database specific random keyword
 
 	/**
@@ -131,6 +127,7 @@ class CI_DB_sqlite_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
diff --git a/system/database/drivers/sqlite/sqlite_result.php b/system/database/drivers/sqlite/sqlite_result.php
index eef9787a1..214841412 100644
--- a/system/database/drivers/sqlite/sqlite_result.php
+++ b/system/database/drivers/sqlite/sqlite_result.php
@@ -115,6 +115,7 @@ class CI_DB_sqlite_result extends CI_DB_result {
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
+	 * @param	int	$n = 0
 	 * @return	bool
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index cc35d319f..22c72b9b8 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -46,10 +46,6 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// The character used for escaping
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = ' ESCAPE \'%s\' ';
-	protected $_like_escape_chr = '!';
-
 	protected $_random_keyword = ' RANDOM()';
 
 	/**
@@ -107,13 +103,12 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @todo	Implement use of SQLite3::querySingle(), if needed
+	 * @param	string	$sql
 	 * @return	mixed	SQLite3Result object or bool
 	 */
 	protected function _execute($sql)
 	{
-		// TODO: Implement use of SQLite3::querySingle(), if needed
-
 		return $this->is_write_type($sql)
 			? $this->conn_id->exec($sql)
 			: $this->conn_id->query($sql);
@@ -124,6 +119,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -288,25 +284,16 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * The error message string
+	 * Error
 	 *
-	 * @return	string
-	 */
-	protected function _error_message()
-	{
-		return $this->conn_id->lastErrorMsg();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * The error message number
+	 * Returns an array containing code and message of the last
+	 * database error that has occured.
 	 *
-	 * @return	int
+	 * @return	array
 	 */
-	protected function _error_number()
+	public function error()
 	{
-		return $this->conn_id->lastErrorCode();
+		return array('code' => $this->conn_id->lastErrorCode(), 'message' => $this->conn_id->lastErrorMsg());
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/sqlite3/sqlite3_result.php b/system/database/drivers/sqlite3/sqlite3_result.php
index 117fb3ce8..35aecda36 100644
--- a/system/database/drivers/sqlite3/sqlite3_result.php
+++ b/system/database/drivers/sqlite3/sqlite3_result.php
@@ -167,6 +167,7 @@ class CI_DB_sqlite3_result extends CI_DB_result {
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
+	 * @param	$n = 0	(ignored)
 	 * @return	array
 	 */
 	protected function _data_seek($n = 0)
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 8bd18bd76..32f1a59d6 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -45,10 +45,6 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	// The character used for escaping
 	protected $_escape_char = '"';
 
-	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str = " ESCAPE '%s' ";
-	protected $_like_escape_chr = '!';
-
 	protected $_random_keyword = ' NEWID()';
 
 	// SQLSRV-specific properties
@@ -57,19 +53,21 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	/**
 	 * Non-persistent database connection
 	 *
+	 * @param	bool	$pooling = FALSE
 	 * @return	resource
 	 */
 	public function db_connect($pooling = FALSE)
 	{
-		// Check for a UTF-8 charset being passed as CI's default 'utf8'.
-		$character_set = (0 === strcasecmp('utf8', $this->char_set)) ? 'UTF-8' : $this->char_set;
+		$charset = in_array(strtolower($this->char_set), array('utf-8', 'utf8'), TRUE)
+			? 'UTF-8' : SQLSRV_ENC_CHAR;
 
 		$connection = array(
 			'UID'			=> empty($this->username) ? '' : $this->username,
 			'PWD'			=> empty($this->password) ? '' : $this->password,
 			'Database'		=> $this->database,
-			'ConnectionPooling'	=> $pooling ? 1 : 0,
-			'CharacterSet'		=> $character_set,
+			'ConnectionPooling'	=> ($pooling === TRUE) ? 1 : 0,
+			'CharacterSet'		=> $charset,
+			'Encrypt'		=> ($this->encrypt === TRUE) ? 1 : 0,
 			'ReturnDatesAsStrings'	=> 1
 		);
 
@@ -147,6 +145,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode = FALSE
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -225,7 +224,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 */
 	public function affected_rows()
 	{
-		return sqlrv_rows_affected($this->result_id);
+		return sqlsrv_rows_affected($this->result_id);
 	}
 
 	// --------------------------------------------------------------------
@@ -362,49 +361,19 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		return is_array($tables) ? implode(', ', $tables) : $tables;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause (ignored)
-	 * @param	array	the limit clause (ignored)
-	 * @param	array	the like clause
 	 * @return	string
 	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
+	protected function _update($table, $values)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
-
-		if ( ! empty($like))
-		{
-			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -433,23 +402,16 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	array	the like clause
-	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table)
 	{
-		$conditions = array();
-
-		empty($where) OR $conditions[] = implode(' ', $where);
-		empty($like) OR $conditions[] = implode(' ', $like);
-
-		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
+		if ($this->qb_limit)
+		{
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+		}
 
-		return ($limit)
-			? 'WITH ci_delete AS (SELECT TOP '.$limit.' * FROM '.$table.$conditions.') DELETE FROM ci_delete'
-			: 'DELETE FROM '.$table.$conditions;
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -460,32 +422,49 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// As of SQL Server 2012 (11.0.*) OFFSET is supported
 		if (version_compare($this->version(), '11', '>='))
 		{
-			return $sql.' OFFSET '.(int) $offset.' ROWS FETCH NEXT '.(int) $limit.' ROWS ONLY';
+			return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
 		}
 
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// An ORDER BY clause is required for ROW_NUMBER() to work
-		if ($offset && ! empty($this->qb_orderby))
+		if ($this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = $this->_compile_order_by();
 
 			// We have to strip the ORDER BY clause
-			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
-
-			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
-				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
-				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+			$sql = trim(substr($sql, 0, strrpos($sql, $orderby)));
+
+			// Get the fields to select from our subquery, so that we can avoid CI_rownum appearing in the actual results
+			if (count($this->qb_select) === 0)
+			{
+				$select = '*'; // Inevitable
+			}
+			else
+			{
+				// Use only field names and their aliases, everything else is out of our scope.
+				$select = array();
+				$field_regexp = ($this->_quoted_identifier)
+					? '("[^\"]+")' : '(\[[^\]]+\])';
+				for ($i = 0, $c = count($this->qb_select); $i < $c; $i++)
+				{
+					$select[] = preg_match('/(?:\s|\.)'.$field_regexp.'$/i', $this->qb_select[$i], $m)
+						? $m[1] : $this->qb_select[$i];
+				}
+				$select = implode(', ', $select);
+			}
+
+			return 'SELECT '.$select." FROM (\n\n"
+				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.trim($orderby).') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
+				."\n\n) ".$this->escape_identifiers('CI_subquery')
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
diff --git a/system/helpers/captcha_helper.php b/system/helpers/captcha_helper.php
index a4383c9d3..3aac14db8 100644
--- a/system/helpers/captcha_helper.php
+++ b/system/helpers/captcha_helper.php
@@ -80,8 +80,7 @@ if ( ! function_exists('create_captcha'))
 		$current_dir = @opendir($img_path);
 		while ($filename = @readdir($current_dir))
 		{
-			if ($filename !== '.' && $filename !== '..' && $filename !== 'index.html'
-				&& (str_replace('.jpg', '', $filename) + $expiration) < $now)
+			if (substr($filename, -4) === '.jpg' && (str_replace('.jpg', '', $filename) + $expiration) < $now)
 			{
 				@unlink($img_path.$filename);
 			}
diff --git a/system/helpers/date_helper.php b/system/helpers/date_helper.php
index a45b3d7ac..51b2b76db 100644
--- a/system/helpers/date_helper.php
+++ b/system/helpers/date_helper.php
@@ -575,22 +575,7 @@ if ( ! function_exists('timezone_menu'))
 			$menu .= ' class="'.$class.'"';
 		}
 
-		// Generate a string from the attributes submitted, if any
-		if (is_array($attributes))
-		{
-			$atts = '';
-			foreach ($attributes as $key => $val)
-			{
-				$atts .= ' '.$key.'="'.$val.'"';
-			}
-			$attributes = $atts;
-		}
-		elseif (is_string($attributes) && strlen($attributes) > 0)
-		{
-			$attributes = ' '.$attributes;
-		}
-
-		$menu .= $attributes.">\n";
+		$menu .= _stringify_attributes($attributes).">\n";
 
 		foreach (timezones() as $key => $val)
 		{
@@ -672,5 +657,136 @@ if ( ! function_exists('timezones'))
 	}
 }
 
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('date_range'))
+{
+	/**
+	 * Date range
+	 *
+	 * Returns a list of dates within a specified period.
+	 *
+	 * @param	int	unix_start	UNIX timestamp of period start date
+	 * @param	int	unix_end|days	UNIX timestamp of period end date
+	 *					or interval in days.
+	 * @param	mixed	is_unix		Specifies whether the second parameter
+	 *					is a UNIX timestamp or a day interval
+	 *					 - TRUE or 'unix' for a timestamp
+	 *					 - FALSE or 'days' for an interval
+	 * @param	string  date_format	Output date format, same as in date()
+	 * @return	array
+	 */
+	function date_range($unix_start = '', $mixed = '', $is_unix = TRUE, $format = 'Y-m-d')
+	{
+		if ($unix_start == '' OR $mixed == '' OR $format == '')
+		{
+			return FALSE;
+		}
+
+		$is_unix = ! ( ! $is_unix OR $is_unix === 'days');
+
+		// Validate input and try strtotime() on invalid timestamps/intervals, just in case
+		if ( ( ! preg_match('/^[0-9]+$/', $unix_start) && ($unix_start = @strtotime($unix_time)) === FALSE)
+			OR ( ! preg_match('/^[0-9]+$/', $mixed) && ($is_unix === FALSE OR ($mixed = @strtotime($mixed)) === FALSE))
+			OR ($is_unix === TRUE && $mixed < $unix_start))
+		{
+			return FALSE;
+		}
+
+		if ($is_unix && ($unix_start == $mixed OR date($format, $unix_start) === date($format, $mixed)))
+		{
+			return array($start_date);
+		}
+
+		$range = array();
+
+		/* NOTE: Even though the DateTime object has many useful features, it appears that
+		 *	 it doesn't always handle properly timezones, when timestamps are passed
+		 *	 directly to its constructor. Neither of the following gave proper results:
+		 *
+		 *		new DateTime('<timestamp>')
+		 *		new DateTime('<timestamp>', '<timezone>')
+		 *
+		 *	 --- available in PHP 5.3:
+		 *
+		 *		DateTime::createFromFormat('<format>', '<timestamp>')
+		 *		DateTime::createFromFormat('<format>', '<timestamp>', '<timezone')
+		 *
+		 *	 ... so we'll have to set the timestamp after the object is instantiated.
+		 *	 Furthermore, in PHP 5.3 we can use DateTime::setTimestamp() to do that and
+		 *	 given that we have UNIX timestamps - we should use it.
+		*/
+		$from = new DateTime();
+
+		if (is_php('5.3'))
+		{
+			$from->setTimestamp($unix_start);
+			if ($is_unix)
+			{
+				$arg = new DateTime();
+				$arg->setTimestamp($mixed);
+			}
+			else
+			{
+				$arg = (int) $mixed;
+			}
+
+			$period = new DatePeriod($from, new DateInterval('P1D'), $arg);
+			foreach ($period as $date)
+			{
+				$range[] = $date->format($format);
+			}
+
+			/* If a period end date was passed to the DatePeriod constructor, it might not
+			 * be in our results. Not sure if this is a bug or it's just possible because
+			 * the end date might actually be less than 24 hours away from the previously
+			 * generated DateTime object, but either way - we have to append it manually.
+			 */
+			if ( ! is_int($arg) && $range[count($range) - 1] !== $arg->format($format))
+			{
+				$range[] = $arg->format($format);
+			}
+
+			return $range;
+		}
+
+		$from->setDate(date('Y', $unix_start), date('n', $unix_start), date('j', $unix_start));
+		$from->setTime(date('G', $unix_start), date('i', $unix_start), date('s', $unix_start));
+		if ($is_unix)
+		{
+			$arg = new DateTime();
+			$arg->setDate(date('Y', $mixed), date('n', $mixed), date('j', $mixed));
+			$arg->setTime(date('G', $mixed), date('i', $mixed), date('s', $mixed));
+		}
+		else
+		{
+			$arg = (int) $mixed;
+		}
+		$range[] = $from->format($format);
+
+		if (is_int($arg)) // Day intervals
+		{
+			do
+			{
+				$from->modify('+1 day');
+				$range[] = $from->format($format);
+			}
+			while (--$arg > 0);
+		}
+		else // end date UNIX timestamp
+		{
+			for ($from->modify('+1 day'), $end_check = $arg->format('Ymd'); $from->format('Ymd') < $end_check; $from->modify('+1 day'))
+			{
+				$range[] = $from->format($format);
+			}
+
+			// Our loop only appended dates prior to our end date
+			$range[] = $arg->format($format);
+		}
+
+		return $range;
+	}
+}
+
 /* End of file date_helper.php */
 /* Location: ./system/helpers/date_helper.php */
\ No newline at end of file
diff --git a/system/helpers/directory_helper.php b/system/helpers/directory_helper.php
index e7d3b5e8a..7d6b6770e 100644
--- a/system/helpers/directory_helper.php
+++ b/system/helpers/directory_helper.php
@@ -62,7 +62,7 @@ if ( ! function_exists('directory_map'))
 			while (FALSE !== ($file = readdir($fp)))
 			{
 				// Remove '.', '..', and hidden files [optional]
-				if ( ! trim($file, '.') OR ($hidden === FALSE && $file[0] === '.'))
+				if ($file === '.' OR $file === '..' OR ($hidden === FALSE && $file[0] === '.'))
 				{
 					continue;
 				}
diff --git a/system/helpers/download_helper.php b/system/helpers/download_helper.php
index 09c4de578..0232adfe4 100644
--- a/system/helpers/download_helper.php
+++ b/system/helpers/download_helper.php
@@ -95,7 +95,10 @@ if ( ! function_exists('force_download'))
 		}
 
 		// Clean output buffer
-		ob_clean();
+		if (ob_get_level() !== 0)
+		{
+			ob_clean();
+		}
 
 		// Generate the server headers
 		header('Content-Type: '.$mime);
diff --git a/system/helpers/file_helper.php b/system/helpers/file_helper.php
index 3834d4895..441345b05 100644
--- a/system/helpers/file_helper.php
+++ b/system/helpers/file_helper.php
@@ -109,7 +109,7 @@ if ( ! function_exists('delete_files'))
 	function delete_files($path, $del_dir = FALSE, $level = 0, $htdocs = FALSE)
 	{
 		// Trim the trailing slash
-		$path = rtrim($path, DIRECTORY_SEPARATOR);
+		$path = rtrim($path, '/\\');
 
 		if ( ! $current_dir = @opendir($path))
 		{
@@ -124,7 +124,7 @@ if ( ! function_exists('delete_files'))
 				{
 					delete_files($path.DIRECTORY_SEPARATOR.$filename, $del_dir, $level + 1, $htdocs);
 				}
-				elseif ($htdocs === TRUE && ! preg_match('/^(\.htaccess|index\.(html|htm|php)|web\.config)$/i', $filename))
+				elseif ($htdocs !== TRUE OR ! preg_match('/^(\.htaccess|index\.(html|htm|php)|web\.config)$/i', $filename))
 				{
 					@unlink($path.DIRECTORY_SEPARATOR.$filename);
 				}
diff --git a/system/helpers/html_helper.php b/system/helpers/html_helper.php
index 68ce70248..2372e8174 100644
--- a/system/helpers/html_helper.php
+++ b/system/helpers/html_helper.php
@@ -51,7 +51,7 @@ if ( ! function_exists('heading'))
 	 */
 	function heading($data = '', $h = '1', $attributes = '')
 	{
-		return '<h'.$h.($attributes !== '' ? ' ' : '').$attributes.'>'.$data.'</h'.$h.'>';
+		return '<h'.$h._stringify_attributes($attributes).'>'.$data.'</h'.$h.'>';
 	}
 }
 
@@ -119,23 +119,8 @@ if ( ! function_exists('_list'))
 		// Set the indentation based on the depth
 		$out = str_repeat(' ', $depth);
 
-		// Were any attributes submitted?  If so generate a string
-		if (is_array($attributes))
-		{
-			$atts = '';
-			foreach ($attributes as $key => $val)
-			{
-				$atts .= ' '.$key.'="'.$val.'"';
-			}
-			$attributes = $atts;
-		}
-		elseif (is_string($attributes) && strlen($attributes) > 0)
-		{
-			$attributes = ' '.$attributes;
-		}
-
 		// Write the opening list tag
-		$out .= '<'.$type.$attributes.">\n";
+		$out .= '<'.$type._stringify_attributes($attributes).">\n";
 
 		// Cycle through the list elements.  If an array is
 		// encountered we will recursively call _list()
@@ -191,9 +176,10 @@ if ( ! function_exists('img'))
 	 *
 	 * @param	mixed
 	 * @param	bool
+	 * @param	mixed
 	 * @return	string
 	 */
-	function img($src = '', $index_page = FALSE)
+	function img($src = '', $index_page = FALSE, $attributes = '')
 	{
 		if ( ! is_array($src) )
 		{
@@ -229,7 +215,7 @@ if ( ! function_exists('img'))
 			}
 		}
 
-		return $img.'/>';
+		return $img._stringify_attributes($attributes).' />';
 	}
 }
 
@@ -242,9 +228,9 @@ if ( ! function_exists('doctype'))
 	 *
 	 * Generates a page document type declaration
 	 *
-	 * Valid options are xhtml-11, xhtml-strict, xhtml-trans, xhtml-frame,
-	 * html4-strict, html4-trans, and html4-frame. Values are saved in the
-	 * doctypes config file.
+	 * Examples of valid options: html5, xhtml-11, xhtml-strict, xhtml-trans,
+	 * xhtml-frame, html4-strict, html4-trans, and html4-frame.
+	 * All values are saved in the doctypes config file.
 	 *
 	 * @param	string	type	The doctype to be generated
 	 * @return	string
diff --git a/system/helpers/text_helper.php b/system/helpers/text_helper.php
index 8a1f01b51..016a36c57 100644
--- a/system/helpers/text_helper.php
+++ b/system/helpers/text_helper.php
@@ -89,7 +89,8 @@ if ( ! function_exists('character_limiter'))
 			return $str;
 		}
 
-		$str = preg_replace('/\s+/', ' ', str_replace(array("\r\n", "\r", "\n"), ' ', $str));
+		// a bit complicated, but faster than preg_replace with \s+
+		$str = preg_replace('/ {2,}/', ' ', str_replace(array("\r", "\n", "\t", "\x0B", "\x0C"), ' ', $str));
 
 		if (strlen($str) <= $n)
 		{
@@ -389,19 +390,19 @@ if ( ! function_exists('convert_accented_characters'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Word Wrap
- *
- * Wraps text at the specified character. Maintains the integrity of words.
- * Anything placed between {unwrap}{/unwrap} will not be word wrapped, nor
- * will URLs.
- *
- * @param	string	the text string
- * @param	int	the number of characters to wrap at
- * @return	string
- */
 if ( ! function_exists('word_wrap'))
 {
+	/**
+	 * Word Wrap
+	 *
+	 * Wraps text at the specified character. Maintains the integrity of words.
+	 * Anything placed between {unwrap}{/unwrap} will not be word wrapped, nor
+	 * will URLs.
+	 *
+	 * @param	string	$str		the text string
+	 * @param	int	$charlim = 76	the number of characters to wrap at
+	 * @return	string
+	 */
 	function word_wrap($str, $charlim = 76)
 	{
 		// Set the character limit
diff --git a/system/helpers/typography_helper.php b/system/helpers/typography_helper.php
index af9d16a89..96bedd026 100644
--- a/system/helpers/typography_helper.php
+++ b/system/helpers/typography_helper.php
@@ -60,16 +60,15 @@ if ( ! function_exists('auto_typography'))
 	/**
 	 * Auto Typography Wrapper Function
 	 *
-	 * @param	string
-	 * @param	bool	whether to allow javascript event handlers
-	 * @param	bool	whether to reduce multiple instances of double newlines to two
+	 * @param	string	$str
+	 * @param	bool	$reduce_linebreaks = FALSE	whether to reduce multiple instances of double newlines to two
 	 * @return	string
 	 */
-	function auto_typography($str, $strip_js_event_handlers = TRUE, $reduce_linebreaks = FALSE)
+	function auto_typography($str, $reduce_linebreaks = FALSE)
 	{
 		$CI =& get_instance();
 		$CI->load->library('typography');
-		return $CI->typography->auto_typography($str, $strip_js_event_handlers, $reduce_linebreaks);
+		return $CI->typography->auto_typography($str, $reduce_linebreaks);
 	}
 }
 
diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 39e6343a6..de5bdec31 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -165,7 +165,7 @@ if ( ! function_exists('anchor'))
 
 		if ($attributes !== '')
 		{
-			$attributes = _parse_attributes($attributes);
+			$attributes = _stringify_attributes($attributes);
 		}
 
 		return '<a href="'.$site_url.'"'.$attributes.'>'.$title.'</a>';
@@ -221,10 +221,10 @@ if ( ! function_exists('anchor_popup'))
 			unset($attributes[$key]);
 		}
 
-		$attributes = empty($attributes) ? '' : _parse_attributes($attributes);
+		$attributes = _stringify_attributes($attributes);
 
 		return '<a href="'.$site_url
-			.'" onclick="window.open(\''.$site_url."', '".$window_name."', '"._parse_attributes($atts, TRUE)."'); return false;\""
+			.'" onclick="window.open(\''.$site_url."', '".$window_name."', '"._stringify_attributes($atts, TRUE)."'); return false;\""
 			.$attributes.'>'.$title.'</a>';
 	}
 }
@@ -250,7 +250,7 @@ if ( ! function_exists('mailto'))
 			$title = $email;
 		}
 
-		return '<a href="mailto:'.$email.'"'._parse_attributes($attributes).'>'.$title.'</a>';
+		return '<a href="mailto:'.$email.'"'._stringify_attributes($attributes).'>'.$title.'</a>';
 	}
 }
 
@@ -388,40 +388,43 @@ if ( ! function_exists('auto_link'))
 
 			for ($i = 0, $c = count($matches[0]); $i < $c; $i++)
 			{
-				if (preg_match('|\.$|', $matches[6][$i]))
+				if (preg_match('/(\.|\,)$/i', $matches[6][$i], $m))
 				{
-					$period = '.';
+					$punct = $m[1];
 					$matches[6][$i] = substr($matches[6][$i], 0, -1);
 				}
 				else
 				{
-					$period = '';
+					$punct = '';
 				}
 
 				$str = str_replace($matches[0][$i],
 							$matches[1][$i].'<a href="http'.$matches[4][$i].'://'
 								.$matches[5][$i].$matches[6][$i].'"'.$pop.'>http'
 								.$matches[4][$i].'://'.$matches[5][$i]
-								.$matches[6][$i].'</a>'.$period,
+								.$matches[6][$i].'</a>'.$punct,
 							$str);
 			}
 		}
 
-		if ($type !== 'url' && preg_match_all('/([a-zA-Z0-9_\.\-\+]+)@([a-zA-Z0-9\-]+)\.([a-zA-Z0-9\-\.]*)/i', $str, $matches))
+		if ($type !== 'url' && preg_match_all('/([a-zA-Z0-9_\.\-\+]+)@([a-zA-Z0-9\-]+)\.([a-zA-Z0-9\-\.]+)/i', $str, $matches))
 		{
 			for ($i = 0, $c = count($matches); $i < $c; $i++)
 			{
-				if (preg_match('|\.$|', $matches[3][$i]))
+				if (preg_match('/(\.|\,)$/i', $matches[3][$i], $m))
 				{
-					$period = '.';
+					$punct = $m[1];
 					$matches[3][$i] = substr($matches[3][$i], 0, -1);
 				}
 				else
 				{
-					$period = '';
+					$punct = '';
 				}
 
-				$str = str_replace($matches[0][$i], safe_mailto($matches[1][$i].'@'.$matches[2][$i].'.'.$matches[3][$i]).$period, $str);
+				if (filter_var(($m = $matches[1][$i].'@'.$matches[2][$i].'.'.$matches[3][$i]), FILTER_VALIDATE_EMAIL) !== FALSE)
+				{
+					$str = str_replace($matches[0][$i], safe_mailto($m).$punct, $str);
+				}
 			}
 		}
 
@@ -534,7 +537,7 @@ if ( ! function_exists('redirect'))
 		}
 
 		// IIS environment likely? Use 'refresh' for better compatibility
-		if (DIRECTORY_SEPARATOR !== '/' && $method === 'auto')
+		if ($method === 'auto' && isset($_SERVER['SERVER_SOFTWARE']) && strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS') !== FALSE)
 		{
 			$method = 'refresh';
 		}
@@ -560,47 +563,5 @@ if ( ! function_exists('redirect'))
 	}
 }
 
-// ------------------------------------------------------------------------
-
-if ( ! function_exists('_parse_attributes'))
-{
-	/**
-	 * Parse out the attributes
-	 *
-	 * Some of the functions use this
-	 *
-	 * @param	array
-	 * @param	bool
-	 * @return	string
-	 */
-	function _parse_attributes($attributes, $javascript = FALSE)
-	{
-		if (is_string($attributes))
-		{
-			return ($attributes !== '') ? ' '.$attributes : '';
-		}
-
-		$att = '';
-		foreach ($attributes as $key => $val)
-		{
-			if ($javascript === TRUE)
-			{
-				$att .= $key.'='.$val.',';
-			}
-			else
-			{
-				$att .= ' '.$key.'="'.$val.'"';
-			}
-		}
-
-		if ($javascript === TRUE && $att !== '')
-		{
-			return substr($att, 0, -1);
-		}
-
-		return $att;
-	}
-}
-
 /* End of file url_helper.php */
 /* Location: ./system/helpers/url_helper.php */
\ No newline at end of file
diff --git a/system/language/english/date_lang.php b/system/language/english/date_lang.php
index 229d33d2e..6683e4c69 100644
--- a/system/language/english/date_lang.php
+++ b/system/language/english/date_lang.php
@@ -25,20 +25,20 @@
  * @filesource
  */
 
-$lang['date_year'] = "Year";
-$lang['date_years'] = "Years";
-$lang['date_month'] = "Month";
-$lang['date_months'] = "Months";
-$lang['date_week'] = "Week";
-$lang['date_weeks'] = "Weeks";
-$lang['date_day'] = "Day";
-$lang['date_days'] = "Days";
-$lang['date_hour'] = "Hour";
-$lang['date_hours'] = "Hours";
-$lang['date_minute'] = "Minute";
-$lang['date_minutes'] = "Minutes";
-$lang['date_second'] = "Second";
-$lang['date_seconds'] = "Seconds";
+$lang['date_year'] = 'Year';
+$lang['date_years'] = 'Years';
+$lang['date_month'] = 'Month';
+$lang['date_months'] = 'Months';
+$lang['date_week'] = 'Week';
+$lang['date_weeks'] = 'Weeks';
+$lang['date_day'] = 'Day';
+$lang['date_days'] = 'Days';
+$lang['date_hour'] = 'Hour';
+$lang['date_hours'] = 'Hours';
+$lang['date_minute'] = 'Minute';
+$lang['date_minutes'] = 'Minutes';
+$lang['date_second'] = 'Second';
+$lang['date_seconds'] = 'Seconds';
 
 $lang['UM12']	= '(UTC -12:00) Baker/Howland Island';
 $lang['UM11']	= '(UTC -11:00) Niue';
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index 021776161..6ff0cc2f4 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -42,9 +42,10 @@ $lang['is_numeric']				= 'The %s field must contain only numeric characters.';
 $lang['integer']				= 'The %s field must contain an integer.';
 $lang['regex_match']			= 'The %s field is not in the correct format.';
 $lang['matches']				= 'The %s field does not match the %s field.';
+$lang['differs']        		= 'The %s field must differ from the %s field.';
 $lang['is_unique'] 				= 'The %s field must contain a unique value.';
-$lang['is_natural']				= 'The %s field must contain only positive numbers.';
-$lang['is_natural_no_zero']		= 'The %s field must contain a number greater than zero.';
+$lang['is_natural']				= 'The %s field must only contain digits.';
+$lang['is_natural_no_zero']		= 'The %s field must only contain digits and must be greater than zero.';
 $lang['decimal']				= 'The %s field must contain a decimal number.';
 $lang['less_than']				= 'The %s field must contain a number less than %s.';
 $lang['less_than_equal_to']		= 'The %s field must contain a number less than or equal to %s.';
diff --git a/system/libraries/Driver.php b/system/libraries/Driver.php
index d67ee2549..5d642b982 100644
--- a/system/libraries/Driver.php
+++ b/system/libraries/Driver.php
@@ -54,14 +54,30 @@ class CI_Driver_Library {
 	protected $lib_name;
 
 	/**
+	 * Get magic method
+	 *
 	 * The first time a child is used it won't exist, so we instantiate it
 	 * subsequents calls will go straight to the proper child.
 	 *
-	 * @param	mixed	$child
-	 * @return	mixed
+	 * @param   string  Child class name
+	 * @return  object  Child class
 	 */
 	public function __get($child)
 	{
+		// Try to load the driver
+		return $this->load_driver($child);
+	}
+
+	/**
+	 * Load driver
+	 *
+	 * Separate load_driver call to support explicit driver load by library or user
+	 *
+	 * @param   string  Child class name
+	 * @return  object  Child class
+	 */
+	public function load_driver($child)
+	{
 		if ( ! isset($this->lib_name))
 		{
 			$this->lib_name = get_class($this);
@@ -156,7 +172,8 @@ class CI_Driver {
 	/**
 	 * Array of methods and properties for the parent class(es)
 	 *
-	 * @var array
+	 * @static
+	 * @var	array
 	 */
 	protected static $_reflections = array();
 
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index fdb9be4da..83b442f58 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -94,10 +94,13 @@ class CI_Email {
 	 *
 	 * The constructor can be passed an array of config values
 	 *
+	 * @param	array	$config = array()
 	 * @return	void
 	 */
 	public function __construct($config = array())
 	{
+		$this->charset = config_item('charset');
+
 		if (count($config) > 0)
 		{
 			$this->initialize($config);
@@ -108,6 +111,8 @@ class CI_Email {
 			$this->_safe_mode = (bool) @ini_get('safe_mode');
 		}
 
+		$this->charset = strtoupper($this->charset);
+
 		log_message('debug', 'Email Class Initialized');
 	}
 
@@ -184,11 +189,12 @@ class CI_Email {
 	/**
 	 * Set FROM
 	 *
-	 * @param	string
-	 * @param	string
+	 * @param	string	$from
+	 * @param	string	$name
+	 * @param	string	$return_path = NULL	Return-Path
 	 * @return	object
 	 */
-	public function from($from, $name = '')
+	public function from($from, $name = '', $return_path = NULL)
 	{
 		if (preg_match('/\<(.*)\>/', $from, $match))
 		{
@@ -198,6 +204,10 @@ class CI_Email {
 		if ($this->validate)
 		{
 			$this->validate_email($this->_str_to_array($from));
+			if ($return_path)
+			{
+				$this->validate_email($this->_str_to_array($return_path));
+			}
 		}
 
 		// prepare the display name
@@ -211,12 +221,14 @@ class CI_Email {
 			}
 			else
 			{
-				$name = $this->_prep_q_encoding($name, TRUE);
+				$name = $this->_prep_q_encoding($name);
 			}
 		}
 
 		$this->set_header('From', $name.' <'.$from.'>');
-		$this->set_header('Return-Path', '<'.$from.'>');
+
+		isset($return_path) OR $return_path = $from;
+		$this->set_header('Return-Path', '<'.$return_path.'>');
 
 		return $this;
 	}
@@ -281,16 +293,7 @@ class CI_Email {
 			$this->set_header('To', implode(', ', $to));
 		}
 
-		switch ($this->_get_protocol())
-		{
-			case 'smtp':
-				$this->_recipients = $to;
-			break;
-			case 'sendmail':
-			case 'mail':
-				$this->_recipients = implode(', ', $to);
-			break;
-		}
+		$this->_recipients = $to;
 
 		return $this;
 	}
@@ -404,7 +407,10 @@ class CI_Email {
 	/**
 	 * Assign file attachments
 	 *
-	 * @param	string
+	 * @param	string	$filename
+	 * @param	string	$disposition = 'attachment'
+	 * @param	string	$newname = NULL
+	 * @param	string	$mime = ''
 	 * @return	object
 	 */
 	public function attach($filename, $disposition = '', $newname = NULL, $mime = '')
@@ -741,8 +747,8 @@ class CI_Email {
 	/**
 	 * Build alternative plain text message
 	 *
-	 * This public function provides the raw message for use
-	 * in plain-text headers of HTML-formatted emails.
+	 * Provides the raw message for use in plain-text headers of
+	 * HTML-formatted emails.
 	 * If the user hasn't specified his own alternative message
 	 * it creates one by stripping the HTML
 	 *
@@ -750,9 +756,11 @@ class CI_Email {
 	 */
 	protected function _get_alt_message()
 	{
-		if ($this->alt_message !== '')
+		if ( ! empty($this->alt_message))
 		{
-			return $this->word_wrap($this->alt_message, '76');
+			return ($this->wordwrap)
+				? $this->word_wrap($this->alt_message, 76)
+				: $this->alt_message;
 		}
 
 		$body = preg_match('/\<body.*?\>(.*)\<\/body\>/si', $this->_body, $match) ? $match[1] : $this->_body;
@@ -763,7 +771,9 @@ class CI_Email {
 			$body = str_replace(str_repeat("\n", $i), "\n\n", $body);
 		}
 
-		return $this->word_wrap($body, 76);
+		return ($this->wordwrap)
+			? $this->word_wrap($body, 76)
+			: $body;
 	}
 
 	// --------------------------------------------------------------------
@@ -772,15 +782,15 @@ class CI_Email {
 	 * Word Wrap
 	 *
 	 * @param	string
-	 * @param	int
+	 * @param	int	line-length limit
 	 * @return	string
 	 */
-	public function word_wrap($str, $charlim = '')
+	public function word_wrap($str, $charlim = NULL)
 	{
-		// Se the character limit
-		if ($charlim === '')
+		// Set the character limit, if not already present
+		if (empty($charlim))
 		{
-			$charlim = ($this->wrapchars === '') ? 76 : $this->wrapchars;
+			$charlim = empty($this->wrapchars) ? 76 : $this->wrapchars;
 		}
 
 		// Reduce multiple spaces
@@ -971,7 +981,6 @@ class CI_Email {
 
 				$this->_finalbody = $body.$this->_prep_quoted_printable($this->_body).$this->newline.$this->newline;
 
-
 				if ($this->_get_protocol() === 'mail')
 				{
 					$this->_header_str .= $hdr;
@@ -1091,17 +1100,28 @@ class CI_Email {
 	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
 	 *
 	 * @param	string
-	 * @param	int
 	 * @return	string
 	 */
-	protected function _prep_quoted_printable($str, $charlim = '')
+	protected function _prep_quoted_printable($str)
 	{
-		// Set the character limit
-		// Don't allow over 76, as that will make servers and MUAs barf
-		// all over quoted-printable data
-		if ($charlim === '' OR $charlim > 76)
+		// 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}'), '', $str);
+
+		// RFC 2045 specifies CRLF as "\r\n".
+		// However, many developers choose to override that and violate
+		// the RFC rules due to (apparently) a bug in MS Exchange,
+		// which only works with "\n".
+		if ($this->crlf === "\r\n")
 		{
-			$charlim = 76;
+			if (is_php('5.3'))
+			{
+				return quoted_printable_encode($str);
+			}
+			elseif (function_exists('imap_8bit'))
+			{
+				return imap_8bit($str);
+			}
 		}
 
 		// Reduce multiple spaces & remove nulls
@@ -1113,10 +1133,6 @@ class CI_Email {
 			$str = str_replace(array("\r\n", "\r"), "\n", $str);
 		}
 
-		// 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);
-
 		$escape = '=';
 		$output = '';
 
@@ -1146,7 +1162,7 @@ class CI_Email {
 
 				// If we're at the character limit, add the line to the output,
 				// reset our temp variable, and keep on chuggin'
-				if ((strlen($temp) + strlen($char)) >= $charlim)
+				if ((strlen($temp) + strlen($char)) >= 76)
 				{
 					$output .= $temp.$escape.$this->crlf;
 					$temp = '';
@@ -1169,66 +1185,75 @@ class CI_Email {
 	/**
 	 * Prep Q Encoding
 	 *
-	 * Performs "Q Encoding" on a string for use in email headers.  It's related
-	 * but not identical to quoted-printable, so it has its own method
+	 * Performs "Q Encoding" on a string for use in email headers.
+	 * It's related but not identical to quoted-printable, so it has its
+	 * own method.
 	 *
 	 * @param	string
-	 * @param	bool	set to TRUE for processing From: headers
 	 * @return	string
 	 */
-	protected function _prep_q_encoding($str, $from = FALSE)
+	protected function _prep_q_encoding($str)
 	{
-		$str = str_replace(array("\r", "\n"), array('', ''), $str);
-
-		// Line length must not exceed 76 characters, so we adjust for
-		// a space, 7 extra characters =??Q??=, and the charset that we will add to each line
-		$limit = 75 - 7 - strlen($this->charset);
+		$str = str_replace(array("\r", "\n"), '', $str);
 
-		// these special characters must be converted too
-		$convert = array('_', '=', '?');
-
-		if ($from === TRUE)
+		if ($this->charset === 'UTF-8')
 		{
-			$convert[] = ',';
-			$convert[] = ';';
+			if (MB_ENABLED === TRUE)
+			{
+				return mb_encode_mimeheader($str, $this->charset, 'Q', $this->crlf);
+			}
+			elseif (extension_loaded('iconv'))
+			{
+				$output = @iconv_mime_encode('', $str,
+					array(
+						'scheme' => 'Q',
+						'line-length' => 76,
+						'input-charset' => $this->charset,
+						'output-charset' => $this->charset,
+						'line-break-chars' => $this->crlf
+					)
+				);
+
+				// There are reports that iconv_mime_encode() might fail and return FALSE
+				if ($output !== FALSE)
+				{
+					// 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);
+				}
+
+				$chars = iconv_strlen($str, 'UTF-8');
+			}
 		}
 
-		$output = '';
-		$temp = '';
+		// We might already have this set for UTF-8
+		isset($chars) OR $chars = strlen($str);
 
-		for ($i = 0, $length = strlen($str); $i < $length; $i++)
+		$output = '=?'.$this->charset.'?Q?';
+		for ($i = 0, $length = strlen($output), $iconv = extension_loaded('iconv'); $i < $chars; $i++)
 		{
-			// Grab the next character
-			$char = $str[$i];
-			$ascii = ord($char);
-
-			// convert ALL non-printable ASCII characters and our specials
-			if ($ascii < 32 OR $ascii > 126 OR in_array($char, $convert))
-			{
-				$char = '='.dechex($ascii);
-			}
+			$chr = ($this->charset === 'UTF-8' && $iconv === TRUE)
+				? '='.implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2))
+				: '='.strtoupper(bin2hex($str[$i]));
 
-			// handle regular spaces a bit more compactly than =20
-			if ($ascii === 32)
+			// RFC 2045 sets a limit of 76 characters per line.
+			// We'll append ?= to the end of each line though.
+			if ($length + ($l = strlen($chr)) > 74)
 			{
-				$char = '_';
+				$output .= '?='.$this->crlf // EOL
+					.' =?'.$this->charset.'?Q?'.$chr; // New line
+				$length = 6 + strlen($this->charset) + $l; // Reset the length for the new line
 			}
-
-			// If we're at the character limit, add the line to the output,
-			// reset our temp variable, and keep on chuggin'
-			if ((strlen($temp) + strlen($char)) >= $limit)
+			else
 			{
-				$output .= $temp.$this->crlf;
-				$temp = '';
+				$output .= $chr;
+				$length += $l;
 			}
-
-			// Add the character to our temporary line
-			$temp .= $char;
 		}
 
-		// wrap each line with the shebang, charset, and transfer encoding
-		// the preceding space on successive lines is required for header "folding"
-		return trim(preg_replace('/^(.*)$/m', ' =?'.$this->charset.'?Q?$1?=', $output.$temp));
+		// End the header
+		return $output.'?=';
 	}
 
 	// --------------------------------------------------------------------
@@ -1236,9 +1261,10 @@ class CI_Email {
 	/**
 	 * Send Email
 	 *
+	 * @param	bool	$auto_clear = TRUE
 	 * @return	bool
 	 */
-	public function send()
+	public function send($auto_clear = TRUE)
 	{
 		if ($this->_replyto_flag === FALSE)
 		{
@@ -1257,11 +1283,25 @@ class CI_Email {
 
 		if ($this->bcc_batch_mode && count($this->_bcc_array) > $this->bcc_batch_size)
 		{
-			return $this->batch_bcc_send();
+			$result = $this->batch_bcc_send();
+
+			if ($result && $auto_clear)
+			{
+				$this->clear();
+			}
+
+			return $result;
 		}
 
 		$this->_build_message();
-		return $this->_spool_email();
+		$result = $this->_spool_email();
+
+		if ($result && $auto_clear)
+		{
+			$this->clear();
+		}
+
+		return $result;
 	}
 
 	// --------------------------------------------------------------------
@@ -1334,6 +1374,7 @@ class CI_Email {
 	/**
 	 * Strip line-breaks via callback
 	 *
+	 * @param	string	$matches
 	 * @return	string
 	 */
 	protected function _remove_nl_callback($matches)
@@ -1377,6 +1418,11 @@ class CI_Email {
 	 */
 	protected function _send_with_mail()
 	{
+		if (is_array($this->_recipients))
+		{
+			$this->_recipients = implode(', ', $this->_recipients);
+		}
+
 		if ($this->_safe_mode === TRUE)
 		{
 			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str);
@@ -1385,7 +1431,7 @@ class CI_Email {
 		{
 			// most documentation of sendmail using the "-f" flag lacks a space after it, however
 			// we've encountered servers that seem to require it to be in place.
-			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$this->clean_email($this->_headers['From']));
+			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$this->clean_email($this->_headers['Return-Path']));
 		}
 	}
 
@@ -1398,7 +1444,7 @@ class CI_Email {
 	 */
 	protected function _send_with_sendmail()
 	{
-		$fp = @popen($this->mailpath.' -oi -f '.$this->clean_email($this->_headers['From']).' -t', 'w');
+		$fp = @popen($this->mailpath.' -oi -f '.$this->clean_email($this->_headers['From']).' -t'.' -r '.$this->clean_email($this->_headers['Return-Path']), 'w');
 
 		if ($fp === FALSE OR $fp === NULL)
 		{
@@ -1496,7 +1542,6 @@ class CI_Email {
 	/**
 	 * SMTP Connect
 	 *
-	 * @param	string
 	 * @return	string
 	 */
 	protected function _smtp_connect()
@@ -1671,11 +1716,12 @@ class CI_Email {
 	/**
 	 * Send SMTP data
 	 *
+	 * @param	string	$data
 	 * @return	bool
 	 */
 	protected function _send_data($data)
 	{
-		if ( ! fwrite($this->_smtp_connect, $data . $this->newline))
+		if ( ! fwrite($this->_smtp_connect, $data.$this->newline))
 		{
 			$this->_set_error_message('lang:email_smtp_data_failure', $data);
 			return FALSE;
@@ -1723,47 +1769,6 @@ class CI_Email {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Get IP
-	 *
-	 * @return	string
-	 */
-	protected function _get_ip()
-	{
-		if ($this->_IP !== FALSE)
-		{
-			return $this->_IP;
-		}
-
-		$cip = ( ! empty($_SERVER['HTTP_CLIENT_IP'])) ? $_SERVER['HTTP_CLIENT_IP'] : FALSE;
-		$rip = ( ! empty($_SERVER['REMOTE_ADDR'])) ? $_SERVER['REMOTE_ADDR'] : FALSE;
-		if ($cip) $this->_IP = $cip;
-		elseif ($rip) $this->_IP = $rip;
-		else
-		{
-			$fip = ( ! empty($_SERVER['HTTP_X_FORWARDED_FOR'])) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : FALSE;
-			if ($fip)
-			{
-				$this->_IP = $fip;
-			}
-		}
-
-		if (strpos($this->_IP, ',') !== FALSE)
-		{
-			$x = explode(',', $this->_IP);
-			$this->_IP = end($x);
-		}
-
-		if ( ! preg_match('/^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/', $this->_IP))
-		{
-			$this->_IP = '0.0.0.0';
-		}
-
-		return $this->_IP;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Get Debug Message
 	 *
 	 * @return	string
@@ -1788,7 +1793,8 @@ class CI_Email {
 	/**
 	 * Set Message
 	 *
-	 * @param	string
+	 * @param	string	$msg
+	 * @param	string	$val = ''
 	 * @return	void
 	 */
 	protected function _set_error_message($msg, $val = '')
diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
index 8ffd93aea..73ab8ca7d 100644
--- a/system/libraries/Encrypt.php
+++ b/system/libraries/Encrypt.php
@@ -165,7 +165,7 @@ class CI_Encrypt {
 	 */
 	public function decode($string, $key = '')
 	{
-		if (preg_match('/[^a-zA-Z0-9\/\+=]/', $string))
+		if (preg_match('/[^a-zA-Z0-9\/\+=]/', $string) OR base64_encode(base64_decode($string)) !== $string)
 		{
 			return FALSE;
 		}
@@ -484,7 +484,7 @@ class CI_Encrypt {
 	 */
 	public function set_hash($type = 'sha1')
 	{
-		$this->_hash_type = ($type !== 'sha1' && $type !== 'md5') ? 'sha1' : $type;
+		$this->_hash_type = in_array($type, hash_algos()) ? $type : 'sha1';
 	}
 
 	// --------------------------------------------------------------------
@@ -497,7 +497,7 @@ class CI_Encrypt {
 	 */
 	public function hash($str)
 	{
-		return ($this->_hash_type === 'sha1') ? sha1($str) : md5($str);
+		return hash($this->_hash_type, $str);
 	}
 
 }
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index b490a34ca..91f46b6de 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -134,12 +134,6 @@ class CI_Form_validation {
 		// Automatically load the form helper
 		$this->CI->load->helper('form');
 
-		// Set the character encoding in MB.
-		if (MB_ENABLED === TRUE)
-		{
-			mb_internal_encoding($this->CI->config->item('charset'));
-		}
-
 		log_message('debug', 'Form Validation Class Initialized');
 	}
 
@@ -977,6 +971,20 @@ class CI_Form_validation {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Differs from another field
+	 *
+	 * @param	string
+	 * @param	string	field
+	 * @return	bool
+	 */
+	public function differs($str, $field)
+	{
+		return ! (isset($this->_field_data[$field]) && $this->_field_data[$field]['postdata'] === $str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Is Unique
 	 *
 	 * Check if the input value doesn't already exist
diff --git a/system/libraries/Ftp.php b/system/libraries/Ftp.php
index 76f5e151a..ae85fdf37 100644
--- a/system/libraries/Ftp.php
+++ b/system/libraries/Ftp.php
@@ -44,6 +44,12 @@ class CI_FTP {
 	public $debug		= FALSE;
 	public $conn_id		= FALSE;
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array	$config = array()
+	 * @return	void
+	 */
 	public function __construct($config = array())
 	{
 		if (count($config) > 0)
@@ -474,6 +480,7 @@ class CI_FTP {
 	/**
 	 * FTP List files in the specified directory
 	 *
+	 * @param	string	$path = '.'
 	 * @return	array
 	 */
 	public function list_files($path = '.')
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index 899b995d4..ef4187847 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -1320,6 +1320,13 @@ class CI_Image_lib {
 				imagestring($src_img, $this->wm_font_size, $x_shad, $y_shad, $this->wm_text, $drp_color);
 				imagestring($src_img, $this->wm_font_size, $x_axis, $y_axis, $this->wm_text, $txt_color);
 			}
+
+			// We can preserve transparency for PNG images
+			if ($this->image_type === 3)
+			{
+				imagealphablending($src_img, FALSE);
+				imagesavealpha($src_img, TRUE);
+			}
 		}
 
 		// Output the final image
diff --git a/system/libraries/Javascript.php b/system/libraries/Javascript.php
index 5c8b09217..60309cd83 100644
--- a/system/libraries/Javascript.php
+++ b/system/libraries/Javascript.php
@@ -38,6 +38,12 @@ class CI_Javascript {
 
 	protected $_javascript_location = 'js';
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array	$params = array()
+	 * @return	void
+	 */
 	public function __construct($params = array())
 	{
 		$defaults = array('js_library_driver' => 'jquery', 'autoload' => TRUE);
@@ -312,8 +318,7 @@ class CI_Javascript {
 	 *
 	 * Outputs a javascript library mouseup event
 	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
+	 * @param	string	$js	Code to execute
 	 * @return	string
 	 */
 	public function ready($js)
@@ -394,9 +399,10 @@ class CI_Javascript {
 	 *
 	 * Outputs a javascript library animate event
 	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
+	 * @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 = '')
@@ -546,10 +552,11 @@ class CI_Javascript {
 	 *
 	 * Outputs a javascript library toggle class event
 	 *
-	 * @param	string	- element
+	 * @param	string	$element = 'this'
+	 * @param	string	$class = ''
 	 * @return	string
 	 */
-	public function toggleClass($element = 'this', $class='')
+	public function toggleClass($element = 'this', $class = '')
 	{
 		return $this->js->_toggleClass($element, $class);
 	}
@@ -579,7 +586,8 @@ class CI_Javascript {
 	 *
 	 * gather together all script needing to be output
 	 *
-	 * @param	string	The element to attach the event to
+	 * @param	string	$view_var = 'script_foot'
+	 * @param	bool	$script_tags = TRUE
 	 * @return	string
 	 */
 	public function compile($view_var = 'script_foot', $script_tags = TRUE)
@@ -587,6 +595,8 @@ class CI_Javascript {
 		$this->js->_compile($view_var, $script_tags);
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Clear Compile
 	 *
@@ -606,7 +616,8 @@ class CI_Javascript {
 	 *
 	 * Outputs a <script> tag with the source as an external js file
 	 *
-	 * @param	string	The element to attach the event to
+	 * @param	string	$external_file = ''
+	 * @param	bool	$relative = FALSE
 	 * @return	string
 	 */
 	public function external($external_file = '', $relative = FALSE)
@@ -799,7 +810,8 @@ class CI_Javascript {
 	 *
 	 * Ensures a standard json value and escapes values
 	 *
-	 * @param	mixed
+	 * @param	mixed	$result
+	 * @param	bool	$is_key = FALSE
 	 * @return	string
 	 */
 	protected function _prep_args($result, $is_key = FALSE)
diff --git a/system/libraries/Pagination.php b/system/libraries/Pagination.php
index 5573f6407..36b57b332 100644
--- a/system/libraries/Pagination.php
+++ b/system/libraries/Pagination.php
@@ -52,20 +52,20 @@ class CI_Pagination {
 	protected $full_tag_open		= '';
 	protected $full_tag_close		= '';
 	protected $first_tag_open		= '';
-	protected $first_tag_close		= '&nbsp;';
-	protected $last_tag_open		= '&nbsp;';
+	protected $first_tag_close		= '';
+	protected $last_tag_open		= '';
 	protected $last_tag_close		= '';
 	protected $first_url			= ''; // Alternative URL for the First Page.
-	protected $cur_tag_open			= '&nbsp;<strong>';
+	protected $cur_tag_open			= '<strong>';
 	protected $cur_tag_close		= '</strong>';
-	protected $next_tag_open		= '&nbsp;';
-	protected $next_tag_close		= '&nbsp;';
-	protected $prev_tag_open		= '&nbsp;';
+	protected $next_tag_open		= '';
+	protected $next_tag_close		= '';
+	protected $prev_tag_open		= '';
 	protected $prev_tag_close		= '';
-	protected $num_tag_open			= '&nbsp;';
+	protected $num_tag_open			= '';
 	protected $num_tag_close		= '';
 	protected $page_query_string	= FALSE;
-	protected $query_string_segment 	= 'per_page';
+	protected $query_string_segment = 'per_page';
 	protected $display_pages		= TRUE;
 	protected $_attributes			= '';
 	protected $_link_types			= array();
@@ -157,7 +157,7 @@ class CI_Pagination {
 		// See if we are using a prefix or suffix on links
 		if ($this->prefix !== '' OR $this->suffix !== '')
 		{
-			$this->cur_page = (int) str_replace(array($this->prefix, $this->suffix), '', $CI->uri->segment($this->uri_segment));
+			$this->cur_page = (int) str_replace(array($this->prefix, $this->suffix), '', $CI->uri->rsegment($this->uri_segment));
 		}
 
 		if ($CI->config->item('enable_query_strings') === TRUE OR $this->page_query_string === TRUE)
@@ -169,7 +169,7 @@ class CI_Pagination {
 		}
 		elseif ( ! $this->cur_page && $CI->uri->segment($this->uri_segment) !== $base_page)
 		{
-			$this->cur_page = (int) $CI->uri->segment($this->uri_segment);
+			$this->cur_page = (int) $CI->uri->rsegment($this->uri_segment);
 		}
 
 		// Set current page to 1 if it's not valid or if using page numbers instead of offset
@@ -215,7 +215,8 @@ class CI_Pagination {
 		// string. If post, add a trailing slash to the base URL if needed
 		if ($CI->config->item('enable_query_strings') === TRUE OR $this->page_query_string === TRUE)
 		{
-			$this->base_url = rtrim($this->base_url).'&amp;'.$this->query_string_segment.'=';
+			$segment = (strpos($this->base_url, '?')) ? '&amp;' : '?';
+			$this->base_url = rtrim($this->base_url).$segment.$this->query_string_segment.'=';
 		}
 		else
 		{
diff --git a/system/libraries/Session.php b/system/libraries/Session.php
deleted file mode 100644
index af38dc366..000000000
--- a/system/libraries/Session.php
+++ /dev/null
@@ -1,955 +0,0 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP 5.2.4 or newer
- *
- * NOTICE OF LICENSE
- *
- * Licensed under the Open Software License version 3.0
- *
- * This source file is subject to the Open Software License (OSL 3.0) that is
- * bundled with this package in the files license.txt / license.rst.  It is
- * also available through the world wide web at this URL:
- * http://opensource.org/licenses/OSL-3.0
- * If you did not receive a copy of the license and are unable to obtain it
- * through the world wide web, please send an email to
- * licensing@ellislab.com so we can send you a copy immediately.
- *
- * @package		CodeIgniter
- * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
- * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
- * @link		http://codeigniter.com
- * @since		Version 1.0
- * @filesource
- */
-
-/**
- * Session Class
- *
- * @package		CodeIgniter
- * @subpackage	Libraries
- * @category	Sessions
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/libraries/sessions.html
- */
-class CI_Session {
-
-	/**
-	 * Whether to encrypt the session cookie
-	 *
-	 * @var bool
-	 */
-	public $sess_encrypt_cookie		= FALSE;
-
-	/**
-	 * Whether to use to the database for session storage
-	 *
-	 * @var bool
-	 */
-	public $sess_use_database		= FALSE;
-
-	/**
-	 * Name of the database table in which to store sessions
-	 *
-	 * @var string
-	 */
-	public $sess_table_name			= '';
-
-	/**
-	 * Length of time (in seconds) for sessions to expire
-	 *
-	 * @var int
-	 */
-	public $sess_expiration			= 7200;
-
-	/**
-	 * Whether to kill session on close of browser window
-	 *
-	 * @var bool
-	 */
-	public $sess_expire_on_close		= FALSE;
-
-	/**
-	 * Whether to match session on ip address
-	 *
-	 * @var bool
-	 */
-	public $sess_match_ip			= FALSE;
-
-	/**
-	 * Whether to match session on user-agent
-	 *
-	 * @var bool
-	 */
-	public $sess_match_useragent		= TRUE;
-
-	/**
-	 * Name of session cookie
-	 *
-	 * @var string
-	 */
-	public $sess_cookie_name		= 'ci_session';
-
-	/**
-	 * Session cookie prefix
-	 *
-	 * @var string
-	 */
-	public $cookie_prefix			= '';
-
-	/**
-	 * Session cookie path
-	 *
-	 * @var string
-	 */
-	public $cookie_path			= '';
-
-	/**
-	 * Session cookie domain
-	 *
-	 * @var string
-	 */
-	public $cookie_domain			= '';
-
-	/**
-	 * Whether to set the cookie only on HTTPS connections
-	 *
-	 * @var bool
-	 */
-	public $cookie_secure			= FALSE;
-
-	/**
-	 * Whether cookie should be allowed only to be sent by the server
-	 *
-	 * @var bool
-	 */
-	public $cookie_httponly 		= FALSE;
-
-	/**
-	 * Interval at which to update session
-	 *
-	 * @var int
-	 */
-	public $sess_time_to_update		= 300;
-
-	/**
-	 * Key with which to encrypt the session cookie
-	 *
-	 * @var string
-	 */
-	public $encryption_key			= '';
-
-	/**
-	 * String to indicate flash data cookies
-	 *
-	 * @var string
-	 */
-	public $flashdata_key			= 'flash';
-
-	/**
-	 * Timezone to use for the current time
-	 *
-	 * @var string
-	 */
-	public $time_reference			= 'local';
-
-
-	/**
-	 * Session data
-	 *
-	 * @var array
-	 */
-	public $userdata			= array();
-
-	/**
-	 * Reference to CodeIgniter instance
-	 *
-	 * @var object
-	 */
-	public $CI;
-
-	/**
-	 * Current time
-	 *
-	 * @var int
-	 */
-	public $now;
-
-	/**
-	 * Session Constructor
-	 *
-	 * The constructor runs the session routines automatically
-	 * whenever the class is instantiated.
-	 *
-	 * @param	array
-	 * @return	void
-	 */
-	public function __construct($params = array())
-	{
-		log_message('debug', 'Session Class Initialized');
-
-		// Set the super object to a local variable for use throughout the class
-		$this->CI =& get_instance();
-
-		// Set all the session preferences, which can either be set
-		// manually via the $params array above or via the config file
-		foreach (array('sess_encrypt_cookie', 'sess_use_database', 'sess_table_name', 'sess_expiration', 'sess_expire_on_close', 'sess_match_ip', 'sess_match_useragent', 'sess_cookie_name', 'cookie_path', 'cookie_domain', 'cookie_secure', 'cookie_httponly', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key') as $key)
-		{
-			$this->$key = isset($params[$key]) ? $params[$key] : $this->CI->config->item($key);
-		}
-
-		if ($this->encryption_key === '')
-		{
-			show_error('In order to use the Session class you are required to set an encryption key in your config file.');
-		}
-
-		// Load the string helper so we can use the strip_slashes() function
-		$this->CI->load->helper('string');
-
-		// Do we need encryption? If so, load the encryption class
-		if ($this->sess_encrypt_cookie === TRUE)
-		{
-			$this->CI->load->library('encrypt');
-		}
-
-		// Are we using a database? If so, load it
-		if ($this->sess_use_database === TRUE && $this->sess_table_name !== '')
-		{
-			$this->CI->load->database();
-		}
-
-		// Set the "now" time. Can either be GMT or server time, based on the
-		// config prefs. We use this to set the "last activity" time
-		$this->now = $this->_get_time();
-
-		// Set the session length. If the session expiration is
-		// set to zero we'll set the expiration two years from now.
-		if ($this->sess_expiration === 0)
-		{
-			$this->sess_expiration = (60*60*24*365*2);
-		}
-
-		// Set the cookie name
-		$this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name;
-
-		// Run the Session routine. If a session doesn't exist we'll
-		// create a new one. If it does, we'll update it.
-		if ( ! $this->sess_read())
-		{
-			$this->sess_create();
-		}
-		else
-		{
-			$this->sess_update();
-		}
-
-		// Delete 'old' flashdata (from last request)
-		$this->_flashdata_sweep();
-
-		// Mark all new flashdata as old (data will be deleted before next request)
-		$this->_flashdata_mark();
-
-		// Delete expired sessions if necessary
-		$this->_sess_gc();
-
-		log_message('debug', 'Session routines successfully run');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fetch the current session data if it exists
-	 *
-	 * @return	bool
-	 */
-	public function sess_read()
-	{
-		// Fetch the cookie
-		$session = $this->CI->input->cookie($this->sess_cookie_name);
-
-		// No cookie?  Goodbye cruel world!...
-		if ($session === NULL)
-		{
-			log_message('debug', 'A session cookie was not found.');
-			return FALSE;
-		}
-
-		// Decrypt the cookie data
-		if ($this->sess_encrypt_cookie === TRUE)
-		{
-			$session = $this->CI->encrypt->decode($session);
-		}
-		else
-		{
-			// encryption was not used, so we need to check the md5 hash
-			$hash	 = substr($session, strlen($session)-32); // get last 32 chars
-			$session = substr($session, 0, strlen($session)-32);
-
-			// Does the md5 hash match? This is to prevent manipulation of session data in userspace
-			if ($hash !==  md5($session.$this->encryption_key))
-			{
-				log_message('error', 'The session cookie data did not match what was expected. This could be a possible hacking attempt.');
-				$this->sess_destroy();
-				return FALSE;
-			}
-		}
-
-		// Unserialize the session array
-		$session = $this->_unserialize($session);
-
-		// Is the session data we unserialized an array with the correct format?
-		if ( ! is_array($session) OR ! isset($session['session_id'], $session['ip_address'], $session['user_agent'], $session['last_activity']))
-		{
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Is the session current?
-		if (($session['last_activity'] + $this->sess_expiration) < $this->now)
-		{
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Does the IP match?
-		if ($this->sess_match_ip === TRUE && $session['ip_address'] !== $this->CI->input->ip_address())
-		{
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Does the User Agent Match?
-		if ($this->sess_match_useragent === TRUE && trim($session['user_agent']) !== trim(substr($this->CI->input->user_agent(), 0, 120)))
-		{
-			$this->sess_destroy();
-			return FALSE;
-		}
-
-		// Is there a corresponding session in the DB?
-		if ($this->sess_use_database === TRUE)
-		{
-			$this->CI->db->where('session_id', $session['session_id']);
-
-			if ($this->sess_match_ip === TRUE)
-			{
-				$this->CI->db->where('ip_address', $session['ip_address']);
-			}
-
-			if ($this->sess_match_useragent === TRUE)
-			{
-				$this->CI->db->where('user_agent', $session['user_agent']);
-			}
-
-			$query = $this->CI->db->limit(1)->get($this->sess_table_name);
-
-			// No result? Kill it!
-			if ($query->num_rows() === 0)
-			{
-				$this->sess_destroy();
-				return FALSE;
-			}
-
-			// Is there custom data?  If so, add it to the main session array
-			$row = $query->row();
-			if ( ! empty($row->user_data))
-			{
-				$custom_data = $this->_unserialize($row->user_data);
-
-				if (is_array($custom_data))
-				{
-					foreach ($custom_data as $key => $val)
-					{
-						$session[$key] = $val;
-					}
-				}
-			}
-		}
-
-		// Session is valid!
-		$this->userdata = $session;
-		unset($session);
-
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Write the session data
-	 *
-	 * @return	void
-	 */
-	public function sess_write()
-	{
-		// Are we saving custom data to the DB?  If not, all we do is update the cookie
-		if ($this->sess_use_database === FALSE)
-		{
-			$this->_set_cookie();
-			return;
-		}
-
-		// set the custom userdata, the session data we will set in a second
-		$custom_userdata = $this->userdata;
-		$cookie_userdata = array();
-
-		// Before continuing, we need to determine if there is any custom data to deal with.
-		// Let's determine this by removing the default indexes to see if there's anything left in the array
-		// and set the session data while we're at it
-		foreach (array('session_id','ip_address','user_agent','last_activity') as $val)
-		{
-			unset($custom_userdata[$val]);
-			$cookie_userdata[$val] = $this->userdata[$val];
-		}
-
-		// Did we find any custom data? If not, we turn the empty array into a string
-		// since there's no reason to serialize and store an empty array in the DB
-		if (count($custom_userdata) === 0)
-		{
-			$custom_userdata = '';
-		}
-		else
-		{
-			// Serialize the custom data array so we can store it
-			$custom_userdata = $this->_serialize($custom_userdata);
-		}
-
-		// Run the update query
-		$this->CI->db->where('session_id', $this->userdata['session_id']);
-		$this->CI->db->update($this->sess_table_name, array('last_activity' => $this->userdata['last_activity'], 'user_data' => $custom_userdata));
-
-		// Write the cookie. Notice that we manually pass the cookie data array to the
-		// _set_cookie() function. Normally that function will store $this->userdata, but
-		// in this case that array contains custom data, which we do not want in the cookie.
-		$this->_set_cookie($cookie_userdata);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Create a new session
-	 *
-	 * @return	void
-	 */
-	public function sess_create()
-	{
-		$sessid = '';
-		do
-		{
-			$sessid .= mt_rand(0, mt_getrandmax());
-		}
-		while (strlen($sessid) < 32);
-
-		// To make the session ID even more secure we'll combine it with the user's IP
-		$sessid .= $this->CI->input->ip_address();
-
-		$this->userdata = array(
-					'session_id'	=> md5(uniqid($sessid, TRUE)),
-					'ip_address'	=> $this->CI->input->ip_address(),
-					'user_agent'	=> substr($this->CI->input->user_agent(), 0, 120),
-					'last_activity'	=> $this->now,
-					'user_data'	=> ''
-				);
-
-		// Save the data to the DB if needed
-		if ($this->sess_use_database === TRUE)
-		{
-			$this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->userdata));
-		}
-
-		// Write the cookie
-		$this->_set_cookie();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update an existing session
-	 *
-	 * @return	void
-	 */
-	public function sess_update()
-	{
-		// We only update the session every five minutes by default
-		if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
-		{
-			return;
-		}
-
-		// _set_cookie() will handle this for us if we aren't using database sessions
-		// by pushing all userdata to the cookie.
-		$cookie_data = NULL;
-
-		/* Changing the session ID during an AJAX call causes problems,
-		 * so we'll only update our last_activity
-		 */
-		if ($this->CI->input->is_ajax_request())
-		{
-			$this->userdata['last_activity'] = $this->now;
-
-			// Update the session ID and last_activity field in the DB if needed
-			if ($this->sess_use_database === TRUE)
-			{
-				// set cookie explicitly to only have our session data
-				$cookie_data = array();
-				foreach (array('session_id','ip_address','user_agent','last_activity') as $val)
-				{
-					$cookie_data[$val] = $this->userdata[$val];
-				}
-
-				$this->CI->db->query($this->CI->db->update_string($this->sess_table_name,
-											array('last_activity' => $this->userdata['last_activity']),
-											array('session_id' => $this->userdata['session_id'])));
-			}
-
-			return $this->_set_cookie($cookie_data);
-		}
-
-		// Save the old session id so we know which record to
-		// update in the database if we need it
-		$old_sessid = $this->userdata['session_id'];
-		$new_sessid = '';
-		do
-		{
-			$new_sessid .= mt_rand(0, mt_getrandmax());
-		}
-		while (strlen($new_sessid) < 32);
-
-		// To make the session ID even more secure we'll combine it with the user's IP
-		$new_sessid .= $this->CI->input->ip_address();
-
-		// Turn it into a hash and update the session data array
-		$this->userdata['session_id'] = $new_sessid = md5(uniqid($new_sessid, TRUE));
-		$this->userdata['last_activity'] = $this->now;
-
-		// Update the session ID and last_activity field in the DB if needed
-		if ($this->sess_use_database === TRUE)
-		{
-			// set cookie explicitly to only have our session data
-			$cookie_data = array();
-			foreach (array('session_id','ip_address','user_agent','last_activity') as $val)
-			{
-				$cookie_data[$val] = $this->userdata[$val];
-			}
-
-			$this->CI->db->query($this->CI->db->update_string($this->sess_table_name, array('last_activity' => $this->now, 'session_id' => $new_sessid), array('session_id' => $old_sessid)));
-		}
-
-		// Write the cookie
-		$this->_set_cookie($cookie_data);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Destroy the current session
-	 *
-	 * @return	void
-	 */
-	public function sess_destroy()
-	{
-		// Kill the session DB row
-		if ($this->sess_use_database === TRUE && isset($this->userdata['session_id']))
-		{
-			$this->CI->db->where('session_id', $this->userdata['session_id']);
-			$this->CI->db->delete($this->sess_table_name);
-		}
-
-		// Kill the cookie
-		setcookie(
-				$this->sess_cookie_name,
-				addslashes(serialize(array())),
-				($this->now - 31500000),
-				$this->cookie_path,
-				$this->cookie_domain,
-				0
-			);
-
-		// Kill session data
-		$this->userdata = array();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fetch a specific item from the session array
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function userdata($item)
-	{
-		return isset($this->userdata[$item]) ? $this->userdata[$item] : NULL;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fetch all session data
-	 *
-	 * @return	array
-	 */
-	public function all_userdata()
-	{
-		return $this->userdata;
-	}
-
-	// --------------------------------------------------------------------------
-
-	/**
-	 * Fetch all flashdata
-	 *
-	 * @return	array
-	 */
-	public function all_flashdata()
-	{
-		$out = array();
-
-		// loop through all userdata
-		foreach ($this->all_userdata() as $key => $val)
-		{
-			// if it contains flashdata, add it
-			if (strpos($key, 'flash:old:') !== FALSE)
-			{
-				$out[$key] = $val;
-			}
-		}
-		return $out;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Add or change data in the "userdata" array
-	 *
-	 * @param	mixed
-	 * @param	string
-	 * @return	void
-	 */
-	public function set_userdata($newdata = array(), $newval = '')
-	{
-		if (is_string($newdata))
-		{
-			$newdata = array($newdata => $newval);
-		}
-
-		if (count($newdata) > 0)
-		{
-			foreach ($newdata as $key => $val)
-			{
-				$this->userdata[$key] = $val;
-			}
-		}
-
-		$this->sess_write();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Delete a session variable from the "userdata" array
-	 *
-	 * @param	array
-	 * @return	void
-	 */
-	public function unset_userdata($newdata = array())
-	{
-		if (is_string($newdata))
-		{
-			$newdata = array($newdata => '');
-		}
-
-		if (count($newdata) > 0)
-		{
-			foreach ($newdata as $key => $val)
-			{
-				unset($this->userdata[$key]);
-			}
-		}
-
-		$this->sess_write();
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Add or change flashdata, only available
-	 * until the next request
-	 *
-	 * @param	mixed
-	 * @param	string
-	 * @return	void
-	 */
-	public function set_flashdata($newdata = array(), $newval = '')
-	{
-		if (is_string($newdata))
-		{
-			$newdata = array($newdata => $newval);
-		}
-
-		if (count($newdata) > 0)
-		{
-			foreach ($newdata as $key => $val)
-			{
-				$this->set_userdata($this->flashdata_key.':new:'.$key, $val);
-			}
-		}
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Keeps existing flashdata available to next request.
-	 *
-	 * @param	string
-	 * @return	void
-	 */
-	public function keep_flashdata($key)
-	{
-		// 'old' flashdata gets removed. Here we mark all
-		// flashdata as 'new' to preserve it from _flashdata_sweep()
-		// Note the function will return NULL if the $key
-		// provided cannot be found
-		$value = $this->userdata($this->flashdata_key.':old:'.$key);
-
-		$this->set_userdata($this->flashdata_key.':new:'.$key, $value);
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Fetch a specific flashdata item from the session array
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function flashdata($key)
-	{
-		return $this->userdata($this->flashdata_key.':old:'.$key);
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Identifies flashdata as 'old' for removal
-	 * when _flashdata_sweep() runs.
-	 *
-	 * @return	void
-	 */
-	protected function _flashdata_mark()
-	{
-		$userdata = $this->all_userdata();
-		foreach ($userdata as $name => $value)
-		{
-			$parts = explode(':new:', $name);
-			if (is_array($parts) && count($parts) === 2)
-			{
-				$this->set_userdata($this->flashdata_key.':old:'.$parts[1], $value);
-				$this->unset_userdata($name);
-			}
-		}
-	}
-
-	// ------------------------------------------------------------------------
-
-	/**
-	 * Removes all flashdata marked as 'old'
-	 *
-	 * @return	void
-	 */
-	protected function _flashdata_sweep()
-	{
-		$userdata = $this->all_userdata();
-		foreach ($userdata as $key => $value)
-		{
-			if (strpos($key, ':old:'))
-			{
-				$this->unset_userdata($key);
-			}
-		}
-
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Get the "now" time
-	 *
-	 * @return	string
-	 */
-	protected function _get_time()
-	{
-		if ($this->time_reference === 'local' OR $this->time_reference === date_default_timezone_get())
-		{
-			return time();
-		}
-
-		$datetime = new DateTime('now', new DateTimeZone($this->time_reference));
-		sscanf($datetime->format('j-n-Y G:i:s'), '%d-%d-%d %d:%d:%d', $day, $month, $year, $hour, $minute, $second);
-
-		return mktime($hour, $minute, $second, $month, $day, $year);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Write the session cookie
-	 *
-	 * @param	mixed
-	 * @return	void
-	 */
-	protected function _set_cookie($cookie_data = NULL)
-	{
-		if (is_null($cookie_data))
-		{
-			$cookie_data = $this->userdata;
-		}
-
-		// Serialize the userdata for the cookie
-		$cookie_data = $this->_serialize($cookie_data);
-
-		if ($this->sess_encrypt_cookie === TRUE)
-		{
-			$cookie_data = $this->CI->encrypt->encode($cookie_data);
-		}
-		else
-		{
-			// if encryption is not used, we provide an md5 hash to prevent userside tampering
-			$cookie_data = $cookie_data.md5($cookie_data.$this->encryption_key);
-		}
-
-		$expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time();
-
-		// Set the cookie
-		setcookie(
-			$this->sess_cookie_name,
-			$cookie_data,
-			$expire,
-			$this->cookie_path,
-			$this->cookie_domain,
-			$this->cookie_secure,
-			$this->cookie_httponly
-		);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Serialize an array
-	 *
-	 * This function first converts any slashes found in the array to a temporary
-	 * marker, so when it gets unserialized the slashes will be preserved
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _serialize($data)
-	{
-		if (is_array($data))
-		{
-			array_walk_recursive($data, array(&$this, '_escape_slashes'));
-		}
-		elseif (is_string($data))
-		{
-			$data = str_replace('\\', '{{slash}}', $data);
-		}
-		return serialize($data);
-	}
-
-	/**
-	 * Escape slashes
-	 *
-	 * This function converts any slashes found into a temporary marker
-	 *
-	 * @param	string
-	 * @param	string
-	 * @return	void
-	 */
-	protected function _escape_slashes(&$val, $key)
-	{
-		if (is_string($val))
-		{
-			$val = str_replace('\\', '{{slash}}', $val);
-		}
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Unserialize
-	 *
-	 * This function unserializes a data string, then converts any
-	 * temporary slash markers back to actual slashes
-	 *
-	 * @param	array
-	 * @return	string
-	 */
-	protected function _unserialize($data)
-	{
-		$data = @unserialize(strip_slashes(trim($data)));
-
-		if (is_array($data))
-		{
-			array_walk_recursive($data, array(&$this, '_unescape_slashes'));
-			return $data;
-		}
-
-		return is_string($data) ? str_replace('{{slash}}', '\\', $data) : $data;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Unescape slashes
-	 *
-	 * This function converts any slash markers back into actual slashes
-	 *
-	 * @param	string
-	 * @param	string
-	 * @return	void
-	 */
-	protected function _unescape_slashes(&$val, $key)
-	{
-		if (is_string($val))
-		{
-	 		$val= str_replace('{{slash}}', '\\', $val);
-		}
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Garbage collection
-	 *
-	 * This deletes expired session rows from database
-	 * if the probability percentage is met
-	 *
-	 * @return	void
-	 */
-	protected function _sess_gc()
-	{
-		if ($this->sess_use_database !== TRUE)
-		{
-			return;
-		}
-
-		$probability = ini_get('session.gc_probability');
-		$divisor = ini_get('session.gc_divisor');
-
-		srand(time());
-		if ((mt_rand(0, $divisor) / $divisor) < $probability)
-		{
-			$expire = $this->now - $this->sess_expiration;
-
-			$this->CI->db->where('last_activity < '.$expire);
-			$this->CI->db->delete($this->sess_table_name);
-
-			log_message('debug', 'Session garbage collection performed.');
-		}
-	}
-
-}
-
-/* End of file Session.php */
-/* Location: ./system/libraries/Session.php */
\ No newline at end of file
diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
new file mode 100755
index 000000000..978506062
--- /dev/null
+++ b/system/libraries/Session/Session.php
@@ -0,0 +1,714 @@
+<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst.  It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2006 - 2012 EllisLab, Inc.
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 2.0
+ * @filesource
+ */
+
+/**
+ * CodeIgniter Session Class
+ *
+ * The user interface defined by EllisLabs, now with puggable drivers to manage different storage mechanisms.
+ * By default, the cookie session driver will load, but the 'sess_driver' config/param item (see above) can be
+ * used to specify the 'native' driver, or any other you might create.
+ * Once loaded, this driver setup is a drop-in replacement for the former CI_Session library, taking its place as the
+ * 'session' member of the global controller framework (e.g.: $CI->session or $this->session).
+ * In keeping with the CI_Driver methodology, multiple drivers may be loaded, although this might be a bit confusing.
+ * The CI_Session library class keeps track of the most recently loaded driver as "current" to call for driver methods.
+ * Ideally, one driver is loaded and all calls go directly through the main library interface. However, any methods
+ * called through the specific driver will switch the "current" driver to itself before invoking the library method
+ * (which will then call back into the driver for low-level operations). So, alternation between two drivers can be
+ * achieved by specifying which driver to use for each call (e.g.: $this->session->native->set_userdata('foo', 'bar');
+ * $this->session->cookie->userdata('foo'); $this->session->native->unset_userdata('foo');). Notice in the previous
+ * example that the _native_ userdata value 'foo' would be set to 'bar', which would NOT be returned by the call for
+ * the _cookie_ userdata 'foo', nor would the _cookie_ value be unset by the call to unset the _native_ 'foo' value.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+class CI_Session extends CI_Driver_Library {
+
+	public $params = array();
+	protected $current = NULL;
+	protected $userdata = array();
+
+	const FLASHDATA_KEY = 'flash';
+	const FLASHDATA_NEW = ':new:';
+	const FLASHDATA_OLD = ':old:';
+	const FLASHDATA_EXP = ':exp:';
+	const EXPIRATION_KEY = '__expirations';
+	const TEMP_EXP_DEF = 300;
+
+	/**
+	 * CI_Session constructor
+	 *
+	 * The constructor loads the configured driver ('sess_driver' in config.php or as a parameter), running
+	 * routines in its constructor, and manages flashdata aging.
+	 *
+	 * @param	array	Configuration parameters
+	 * @return	void
+	 */
+	public function __construct(array $params = array())
+	{
+		$CI =& get_instance();
+
+		// No sessions under CLI
+		if ($CI->input->is_cli_request())
+		{
+			return;
+		}
+
+		log_message('debug', 'CI_Session Class Initialized');
+
+		// Get valid drivers list
+		$this->valid_drivers = array(
+			'Session_native',
+		   	'Session_cookie'
+		);
+		$key = 'sess_valid_drivers';
+		$drivers = isset($params[$key]) ? $params[$key] : $CI->config->item($key);
+		if ($drivers)
+		{
+			is_array($drivers) OR $drivers = array($drivers);
+
+			// Add driver names to valid list
+			foreach ($drivers as $driver)
+			{
+				if ( ! in_array(strtolower($driver), array_map('strtolower', $this->valid_drivers)))
+				{
+					$this->valid_drivers[] = $driver;
+				}
+			}
+		}
+
+		// Get driver to load
+		$key = 'sess_driver';
+		$driver = isset($params[$key]) ? $params[$key] : $CI->config->item($key);
+		if ( ! $driver)
+		{
+			$driver = 'cookie';
+		}
+
+		if ( ! in_array('session_'.strtolower($driver), array_map('strtolower', $this->valid_drivers)))
+		{
+			$this->valid_drivers[] = 'Session_'.$driver;
+		}
+
+		// Save a copy of parameters in case drivers need access
+		$this->params = $params;
+
+		// Load driver and get array reference
+		$this->load_driver($driver);
+
+		// Delete 'old' flashdata (from last request)
+		$this->_flashdata_sweep();
+
+		// Mark all new flashdata as old (data will be deleted before next request)
+		$this->_flashdata_mark();
+
+		// Delete expired tempdata
+		$this->_tempdata_sweep();
+
+		log_message('debug', 'CI_Session routines successfully run');
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Loads session storage driver
+	 *
+	 * @param	string	Driver classname
+	 * @return	object	Loaded driver object
+	 */
+	public function load_driver($driver)
+	{
+		// Save reference to most recently loaded driver as library default and sync userdata
+		$this->current = parent::load_driver($driver);
+		$this->userdata =& $this->current->get_userdata();
+		return $this->current;
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Select default session storage driver
+	 *
+	 * @param	string	Driver classname
+	 * @return	void
+	 */
+	public function select_driver($driver)
+	{
+		// Validate driver name
+		$lowername = strtolower(str_replace('CI_', '', $driver));
+		if (in_array($lowername, array_map('strtolower', $this->valid_drivers)))
+		{
+			// See if driver is loaded
+			$child = str_replace($this->lib_name.'_', '', $driver);
+			if (isset($this->$child))
+			{
+				// See if driver is already current
+				if ($this->$child !== $this->current)
+				{
+					// Make driver current and sync userdata
+					$this->current = $this->$child;
+					$this->userdata =& $this->current->get_userdata();
+				}
+			}
+			else
+			{
+				// Load new driver
+				$this->load_driver($child);
+			}
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Destroy the current session
+	 *
+	 * @return	void
+	 */
+	public function sess_destroy()
+	{
+		// Just call destroy on driver
+		$this->current->sess_destroy();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Regenerate the current session
+	 *
+	 * @param	bool	Destroy session data flag (default: false)
+	 * @return	void
+	 */
+	public function sess_regenerate($destroy = FALSE)
+	{
+		// Call regenerate on driver and resync userdata
+		$this->current->sess_regenerate($destroy);
+		$this->userdata =& $this->current->get_userdata();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch a specific item from the session array
+	 *
+	 * @param	string	Item key
+	 * @return	string	Item value or NULL if not found
+	 */
+	public function userdata($item)
+	{
+		return isset($this->userdata[$item]) ? $this->userdata[$item] : NULL;
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch all session data
+	 *
+	 * @return	array	User data array
+	 */
+	public function all_userdata()
+	{
+		return isset($this->userdata) ? $this->userdata : NULL;
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch all flashdata
+	 *
+	 * @return	array   Flash data array
+	 */
+	public function all_flashdata()
+	{
+		$out = array();
+
+		// loop through all userdata
+		foreach ($this->all_userdata() as $key => $val)
+		{
+			// if it contains flashdata, add it
+			if (strpos($key, self::FLASHDATA_KEY.self::FLASHDATA_OLD) !== FALSE)
+			{
+				$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_OLD, '', $key);
+				$out[$key] = $val;
+			}
+		}
+		return $out;
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Add or change data in the "userdata" array
+	 *
+	 * @param	mixed	Item name or array of items
+	 * @param	string	Item value or empty string
+	 * @return	void
+	 */
+	public function set_userdata($newdata = array(), $newval = '')
+	{
+		// Wrap params as array if singular
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		// Set each name/value pair
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$this->userdata[$key] = $val;
+			}
+		}
+
+		// Tell driver data changed
+		$this->current->sess_save();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Delete a session variable from the "userdata" array
+	 *
+	 * @param	mixed	Item name or array of item names
+	 * @return	void
+	 */
+	public function unset_userdata($newdata = array())
+	{
+		// Wrap single name as array
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => '');
+		}
+
+		// Unset each item name
+		if (count($newdata) > 0)
+		{
+			foreach (array_keys($newdata) as $key)
+			{
+				unset($this->userdata[$key]);
+			}
+		}
+
+		// Tell driver data changed
+		$this->current->sess_save();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Determine if an item exists
+	 *
+	 * @param	string	Item name
+	 * @return	bool
+	 */
+	public function has_userdata($item)
+	{
+		return isset($this->userdata[$item]);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Add or change flashdata, only available until the next request
+	 *
+	 * @param	mixed	Item name or array of items
+	 * @param	string	Item value or empty string
+	 * @return	void
+	 */
+	public function set_flashdata($newdata = array(), $newval = '')
+	{
+		// Wrap item as array if singular
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		// Prepend each key name and set value
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
+				$this->set_userdata($flashdata_key, $val);
+			}
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Keeps existing flashdata available to next request.
+	 *
+	 * @param	string	Item key
+	 * @return	void
+	 */
+	public function keep_flashdata($key)
+	{
+		// 'old' flashdata gets removed. Here we mark all flashdata as 'new' to preserve it from _flashdata_sweep()
+		// Note the function will return NULL if the $key provided cannot be found
+		$old_flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key;
+		$value = $this->userdata($old_flashdata_key);
+
+		$new_flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
+		$this->set_userdata($new_flashdata_key, $value);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch a specific flashdata item from the session array
+	 *
+	 * @param	string	Item key
+	 * @return	string
+	 */
+	public function flashdata($key)
+	{
+		// Prepend key and retrieve value
+		$flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key;
+		return $this->userdata($flashdata_key);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Add or change tempdata, only available until expiration
+	 *
+	 * @param	mixed	Item name or array of items
+	 * @param	string	Item value or empty string
+	 * @param	int	Item lifetime in seconds or 0 for default
+	 * @return	void
+	 */
+	public function set_tempdata($newdata = array(), $newval = '', $expire = 0)
+	{
+		// Set expiration time
+		$expire = time() + ($expire ? $expire : self::TEMP_EXP_DEF);
+
+		// Wrap item as array if singular
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		// Get or create expiration list
+		$expirations = $this->userdata(self::EXPIRATION_KEY);
+		if ( ! $expirations)
+		{
+			$expirations = array();
+		}
+
+		// Prepend each key name and set value
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
+				$expirations[$tempdata_key] = $expire;
+				$this->set_userdata($tempdata_key, $val);
+			}
+		}
+
+		// Update expiration list
+		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Delete a temporary session variable from the "userdata" array
+	 *
+	 * @param	mixed	Item name or array of item names
+	 * @return	void
+	 */
+	public function unset_tempdata($newdata = array())
+	{
+		// Get expirations list
+		$expirations = $this->userdata(self::EXPIRATION_KEY);
+		if (empty($expirations))
+		{
+			// Nothing to do
+			return;
+		}
+
+		// Wrap single name as array
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => '');
+		}
+
+		// Prepend each item name and unset
+		if (count($newdata) > 0)
+		{
+			foreach (array_keys($newdata) as $key)
+			{
+				$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
+				unset($expirations[$tempdata_key]);
+				$this->unset_userdata($tempdata_key);
+			}
+		}
+
+		// Update expiration list
+		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch a specific tempdata item from the session array
+	 *
+	 * @param	string	Item key
+	 * @return	string
+	 */
+	public function tempdata($key)
+	{
+		// Prepend key and return value
+		$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
+		return $this->userdata($tempdata_key);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Identifies flashdata as 'old' for removal
+	 * when _flashdata_sweep() runs.
+	 *
+	 * @return	void
+	 */
+	protected function _flashdata_mark()
+	{
+		foreach ($this->all_userdata() as $name => $value)
+		{
+			$parts = explode(self::FLASHDATA_NEW, $name);
+			if (is_array($parts) && count($parts) === 2)
+			{
+				$new_name = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$parts[1];
+				$this->set_userdata($new_name, $value);
+				$this->unset_userdata($name);
+			}
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Removes all flashdata marked as 'old'
+	 *
+	 * @return	void
+	 */
+	protected function _flashdata_sweep()
+	{
+		$userdata = $this->all_userdata();
+		foreach (array_keys($userdata) as $key)
+		{
+			if (strpos($key, self::FLASHDATA_OLD))
+			{
+				$this->unset_userdata($key);
+			}
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Removes all expired tempdata
+	 *
+	 * @return	void
+	 */
+	protected function _tempdata_sweep()
+	{
+		// Get expirations list
+		$expirations = $this->userdata(self::EXPIRATION_KEY);
+		if (empty($expirations))
+		{
+			// Nothing to do
+			return;
+		}
+
+		// Unset expired elements
+		$now = time();
+		$userdata = $this->all_userdata();
+		foreach (array_keys($userdata) as $key)
+		{
+			if (strpos($key, self::FLASHDATA_EXP) && $expirations[$key] < $now)
+			{
+				unset($expirations[$key]);
+				$this->unset_userdata($key);
+			}
+		}
+
+		// Update expiration list
+		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	}
+
+}
+
+// ------------------------------------------------------------------------
+
+/**
+ * CI_Session_driver Class
+ *
+ * Extend this class to make a new CI_Session driver.
+ * A CI_Session driver basically manages an array of name/value pairs with some sort of storage mechanism.
+ * To make a new driver, derive from (extend) CI_Session_driver. Overload the initialize method and read or create
+ * session data. Then implement a save handler to write changed data to storage (sess_save), a destroy handler
+ * to remove deleted data (sess_destroy), and an access handler to expose the data (get_userdata).
+ * Put your driver in the libraries/Session/drivers folder anywhere in the loader paths. This includes the
+ * application directory, the system directory, or any path you add with $CI->load->add_package_path().
+ * Your driver must be named CI_Session_<name>, and your filename must be Session_<name>.php,
+ * preferably also capitalized. (e.g.: CI_Session_foo in libraries/Session/drivers/Session_foo.php)
+ * Then specify the driver by setting 'sess_driver' in your config file or as a parameter when loading the CI_Session
+ * object. (e.g.: $config['sess_driver'] = 'foo'; OR $CI->load->driver('session', array('sess_driver' => 'foo')); )
+ * Already provided are the Native driver, which manages the native PHP $_SESSION array, and
+ * the Cookie driver, which manages the data in a browser cookie, with optional extra storage in a database table.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		EllisLab Dev Team
+ */
+abstract class CI_Session_driver extends CI_Driver {
+
+	protected $CI;
+
+	/**
+	 * Constructor
+	 *
+	 * Gets the CI singleton, so that individual drivers
+	 * don't have to do it separately.
+	 *
+	 * @return	void
+	 */
+	public function __construct()
+	{
+		$this->CI =& get_instance();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Decorate
+	 *
+	 * Decorates the child with the parent driver lib's methods and properties
+	 *
+	 * @param	object	Parent library object
+	 * @return	void
+	 */
+	public function decorate($parent)
+	{
+		// Call base class decorate first
+		parent::decorate($parent);
+
+		// Call initialize method now that driver has access to $this->_parent
+		$this->initialize();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * __call magic method
+	 *
+	 * Handles access to the parent driver library's methods
+	 *
+	 * @param	string	Library method name
+	 * @param	array	Method arguments (default: none)
+	 * @return	mixed
+	 */
+	public function __call($method, $args = array())
+	{
+		// Make sure the parent library uses this driver
+		$this->_parent->select_driver(get_class($this));
+		return parent::__call($method, $args);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Initialize driver
+	 *
+	 * @return	void
+	 */
+	protected function initialize()
+	{
+		// Overload this method to implement initialization
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Save the session data
+	 *
+	 * Data in the array has changed - perform any storage synchronization
+	 * necessary. The child class MUST implement this abstract method!
+	 *
+	 * @return	void
+	 */
+	abstract public function sess_save();
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Destroy the current session
+	 *
+	 * Clean up storage for this session - it has been terminated.
+	 * The child class MUST implement this abstract method!
+	 *
+	 * @return	void
+	 */
+	abstract public function sess_destroy();
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Regenerate the current session
+	 *
+	 * Regenerate the session ID.
+	 * The child class MUST implement this abstract method!
+	 *
+	 * @param	bool	Destroy session data flag (default: false)
+	 * @return	void
+	 */
+	abstract public function sess_regenerate($destroy = FALSE);
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Get a reference to user data array
+	 *
+	 * Give array access to the main CI_Session object.
+	 * The child class MUST implement this abstract method!
+	 *
+	 * @return	array	Reference to userdata
+	 */
+	abstract public function &get_userdata();
+
+}
+
+/* End of file Session.php */
+/* Location: ./system/libraries/Session/Session.php */
\ No newline at end of file
diff --git a/system/libraries/Session/drivers/Session_cookie.php b/system/libraries/Session/drivers/Session_cookie.php
new file mode 100755
index 000000000..8617aec2d
--- /dev/null
+++ b/system/libraries/Session/drivers/Session_cookie.php
@@ -0,0 +1,821 @@
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst. It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+
+/**
+ * Cookie-based session management driver
+ *
+ * This is the classic CI_Session functionality, as written by EllisLab, abstracted out to a driver.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+class CI_Session_cookie extends CI_Session_driver {
+
+	/**
+	 * Whether to encrypt the session cookie
+	 *
+	 * @var bool
+	 */
+	public $sess_encrypt_cookie		= FALSE;
+
+	/**
+	 * Whether to use to the database for session storage
+	 *
+	 * @var bool
+	 */
+	public $sess_use_database		= FALSE;
+
+	/**
+	 * Name of the database table in which to store sessions
+	 *
+	 * @var string
+	 */
+	public $sess_table_name			= '';
+
+	/**
+	 * Length of time (in seconds) for sessions to expire
+	 *
+	 * @var int
+	 */
+	public $sess_expiration			= 7200;
+
+	/**
+	 * Whether to kill session on close of browser window
+	 *
+	 * @var bool
+	 */
+	public $sess_expire_on_close	= FALSE;
+
+	/**
+	 * Whether to match session on ip address
+	 *
+	 * @var bool
+	 */
+	public $sess_match_ip			= FALSE;
+
+	/**
+	 * Whether to match session on user-agent
+	 *
+	 * @var bool
+	 */
+	public $sess_match_useragent	= TRUE;
+
+	/**
+	 * Name of session cookie
+	 *
+	 * @var string
+	 */
+	public $sess_cookie_name		= 'ci_session';
+
+	/**
+	 * Session cookie prefix
+	 *
+	 * @var string
+	 */
+	public $cookie_prefix			= '';
+
+	/**
+	 * Session cookie path
+	 *
+	 * @var string
+	 */
+	public $cookie_path				= '';
+
+	/**
+	 * Session cookie domain
+	 *
+	 * @var string
+	 */
+	public $cookie_domain			= '';
+
+	/**
+	 * Whether to set the cookie only on HTTPS connections
+	 *
+	 * @var bool
+	 */
+	public $cookie_secure			= FALSE;
+
+	/**
+	 * Whether cookie should be allowed only to be sent by the server
+	 *
+	 * @var bool
+	 */
+	public $cookie_httponly 		= FALSE;
+
+	/**
+	 * Interval at which to update session
+	 *
+	 * @var int
+	 */
+	public $sess_time_to_update		= 300;
+
+	/**
+	 * Key with which to encrypt the session cookie
+	 *
+	 * @var string
+	 */
+	public $encryption_key			= '';
+
+	/**
+	 * Timezone to use for the current time
+	 *
+	 * @var string
+	 */
+	public $time_reference			= 'local';
+
+	/**
+	 * Session data
+	 *
+	 * @var array
+	 */
+	public $userdata				= array();
+
+	/**
+	 * Current time
+	 *
+	 * @var int
+	 */
+	public $now;
+
+	/**
+	 * Default userdata keys
+	 *
+	 * @var	array
+	 */
+	protected $defaults = array(
+		'session_id' => NULL,
+		'ip_address' => NULL,
+		'user_agent' => NULL,
+		'last_activity' => NULL
+	);
+
+	/**
+	 * Data needs DB update flag
+	 *
+	 * @var	bool
+	 */
+	protected $data_dirty = FALSE;
+
+	/**
+	 * Initialize session driver object
+	 *
+	 * @return	void
+	 */
+	protected function initialize()
+	{
+		// Set all the session preferences, which can either be set
+		// manually via the $params array or via the config file
+		$prefs = array(
+			'sess_encrypt_cookie',
+			'sess_use_database',
+			'sess_table_name',
+			'sess_expiration',
+			'sess_expire_on_close',
+			'sess_match_ip',
+			'sess_match_useragent',
+			'sess_cookie_name',
+			'cookie_path',
+			'cookie_domain',
+			'cookie_secure',
+			'cookie_httponly',
+			'sess_time_to_update',
+			'time_reference',
+			'cookie_prefix',
+			'encryption_key'
+		);
+
+		foreach ($prefs as $key)
+		{
+			$this->$key = isset($this->_parent->params[$key])
+				? $this->_parent->params[$key]
+				: $this->CI->config->item($key);
+		}
+
+		if ($this->encryption_key === '')
+		{
+			show_error('In order to use the Cookie Session driver you are required to set an encryption key in your config file.');
+		}
+
+		// Load the string helper so we can use the strip_slashes() function
+		$this->CI->load->helper('string');
+
+		// Do we need encryption? If so, load the encryption class
+		if ($this->sess_encrypt_cookie === TRUE)
+		{
+			$this->CI->load->library('encrypt');
+		}
+
+		// Check for database
+		if ($this->sess_use_database === TRUE && $this->sess_table_name !== '')
+		{
+			// Load database driver
+			$this->CI->load->database();
+
+			// Register shutdown function
+			register_shutdown_function(array($this, '_update_db'));
+		}
+
+		// Set the "now" time. Can either be GMT or server time, based on the config prefs.
+		// We use this to set the "last activity" time
+		$this->now = $this->_get_time();
+
+		// Set the session length. If the session expiration is
+		// set to zero we'll set the expiration two years from now.
+		if ($this->sess_expiration === 0)
+		{
+			$this->sess_expiration = (60*60*24*365*2);
+		}
+
+		// Set the cookie name
+		$this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name;
+
+		// Run the Session routine. If a session doesn't exist we'll
+		// create a new one. If it does, we'll update it.
+		if ( ! $this->_sess_read())
+		{
+			$this->_sess_create();
+		}
+		else
+		{
+			$this->_sess_update();
+		}
+
+		// Delete expired sessions if necessary
+		$this->_sess_gc();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Write the session data
+	 *
+	 * @return	void
+	 */
+	public function sess_save()
+	{
+		// Check for database
+		if ($this->sess_use_database === TRUE)
+		{
+			// Mark custom data as dirty so we know to update the DB
+			$this->data_dirty = TRUE;
+		}
+
+		// Write the cookie
+		$this->_set_cookie();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Destroy the current session
+	 *
+	 * @return	void
+	 */
+	public function sess_destroy()
+	{
+		// Kill the session DB row
+		if ($this->sess_use_database === TRUE && isset($this->userdata['session_id']))
+		{
+			$this->CI->db->delete($this->sess_table_name, array('session_id' => $this->userdata['session_id']));
+			$this->data_dirty = FALSE;
+		}
+
+		// Kill the cookie
+		$this->_setcookie($this->sess_cookie_name, '', ($this->now - 31500000),
+			$this->cookie_path, $this->cookie_domain, 0);
+
+		// Kill session data
+		$this->userdata = array();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Regenerate the current session
+	 *
+	 * Regenerate the session id
+	 *
+	 * @param	bool	Destroy session data flag (default: false)
+	 * @return	void
+	 */
+	public function sess_regenerate($destroy = FALSE)
+	{
+		// Check destroy flag
+		if ($destroy)
+		{
+			// Destroy old session and create new one
+			$this->sess_destroy();
+			$this->_sess_create();
+		}
+		else
+		{
+			// Just force an update to recreate the id
+			$this->_sess_update(TRUE);
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Get a reference to user data array
+	 *
+	 * @return	array	Reference to userdata
+	 */
+	public function &get_userdata()
+	{
+		return $this->userdata;
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch the current session data if it exists
+	 *
+	 * @return	bool
+	 */
+	protected function _sess_read()
+	{
+		// Fetch the cookie
+		$session = $this->CI->input->cookie($this->sess_cookie_name);
+
+		// No cookie? Goodbye cruel world!...
+		if ($session === NULL)
+		{
+			log_message('debug', 'A session cookie was not found.');
+			return FALSE;
+		}
+
+		$len = strlen($session) - 40;
+
+		if ($len < 0)
+		{
+			log_message('debug', 'The session cookie was not signed.');
+			return FALSE;
+		}
+
+		// Check cookie authentication
+		$hmac	 = substr($session, $len);
+		$session = substr($session, 0, $len);
+
+		if ($hmac !== hash_hmac('sha1', $session, $this->encryption_key))
+		{
+			log_message('error', 'The session cookie data did not match what was expected.');
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Check for encryption
+		if ($this->sess_encrypt_cookie === TRUE)
+		{
+			// Decrypt the cookie data
+			$session = $this->CI->encrypt->decode($session);
+		}
+
+		// Unserialize the session array
+		$session = $this->_unserialize($session);
+
+		// Is the session data we unserialized an array with the correct format?
+		if ( ! is_array($session) OR ! isset($session['session_id'], $session['ip_address'], $session['user_agent'], $session['last_activity']))
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Is the session current?
+		if (($session['last_activity'] + $this->sess_expiration) < $this->now OR $session['last_activity'] > $this->now)
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Does the IP match?
+		if ($this->sess_match_ip === TRUE && $session['ip_address'] !== $this->CI->input->ip_address())
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Does the User Agent Match?
+		if ($this->sess_match_useragent === TRUE &&
+			trim($session['user_agent']) !== trim(substr($this->CI->input->user_agent(), 0, 120)))
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Is there a corresponding session in the DB?
+		if ($this->sess_use_database === TRUE)
+		{
+			$this->CI->db->where('session_id', $session['session_id']);
+
+			if ($this->sess_match_ip === TRUE)
+			{
+				$this->CI->db->where('ip_address', $session['ip_address']);
+			}
+
+			if ($this->sess_match_useragent === TRUE)
+			{
+				$this->CI->db->where('user_agent', $session['user_agent']);
+			}
+
+			// Is caching in effect? Turn it off
+			$db_cache = $this->CI->db->cache_on;
+			$this->CI->db->cache_off();
+
+			$query = $this->CI->db->limit(1)->get($this->sess_table_name);
+
+			// Was caching in effect?
+			if ($db_cache)
+			{
+				// Turn it back on
+				$this->CI->db->cache_on();
+			}
+
+			// No result? Kill it!
+			if ($query->num_rows() === 0)
+			{
+				$this->sess_destroy();
+				return FALSE;
+			}
+
+			// Is there custom data? If so, add it to the main session array
+			$row = $query->row();
+			if ( ! empty($row->user_data))
+			{
+				$custom_data = $this->_unserialize($row->user_data);
+
+				if (is_array($custom_data))
+				{
+					$session = $session + $custom_data;
+				}
+			}
+		}
+
+		// Session is valid!
+		$this->userdata = $session;
+		return TRUE;
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Create a new session
+	 *
+	 * @return	void
+	 */
+	protected function _sess_create()
+	{
+		// Initialize userdata
+		$this->userdata = array(
+			'session_id'	=> $this->_make_sess_id(),
+			'ip_address'	=> $this->CI->input->ip_address(),
+			'user_agent'	=> substr($this->CI->input->user_agent(), 0, 120),
+			'last_activity'	=> $this->now,
+		);
+
+		// Check for database
+		if ($this->sess_use_database === TRUE)
+		{
+			// Add empty user_data field and save the data to the DB
+			$this->CI->db->set('user_data', '')->insert($this->sess_table_name, $this->userdata);
+		}
+
+		// Write the cookie
+		$this->_set_cookie();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Update an existing session
+	 *
+	 * @param	bool	Force update flag (default: false)
+	 * @return	void
+	 */
+	protected function _sess_update($force = FALSE)
+	{
+		// We only update the session every five minutes by default (unless forced)
+		if ( ! $force && ($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
+		{
+			return;
+		}
+
+		// Update last activity to now
+		$this->userdata['last_activity'] = $this->now;
+
+		// Save the old session id so we know which DB record to update
+		$old_sessid = $this->userdata['session_id'];
+
+		// Changing the session ID during an AJAX call causes problems
+		if ( ! $this->CI->input->is_ajax_request())
+		{
+			// Get new id
+			$this->userdata['session_id'] = $this->_make_sess_id();
+		}
+
+		// Check for database
+		if ($this->sess_use_database === TRUE)
+		{
+			// Update the session ID and last_activity field in the DB
+			$this->CI->db->update($this->sess_table_name, array(
+					 'last_activity' => $this->now,
+					 'session_id' => $this->userdata['session_id']
+			), array('session_id' => $old_sessid));
+		}
+
+		// Write the cookie
+		$this->_set_cookie();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Update database with current data
+	 *
+	 * This gets called from the shutdown function and also
+	 * registered with PHP to run at the end of the request
+	 * so it's guaranteed to update even when a fatal error
+	 * occurs. The first call makes the update and clears the
+	 * dirty flag so it won't happen twice.
+	 *
+	 * @return	void
+	 */
+	public function _update_db()
+	{
+		// Check for database and dirty flag and unsaved
+		if ($this->sess_use_database === TRUE && $this->data_dirty === TRUE)
+		{
+			// Set up activity and data fields to be set
+			// If we don't find custom data, user_data will remain an empty string
+			$set = array(
+				'last_activity' => $this->userdata['last_activity'],
+				'user_data' => ''
+			);
+
+			// Get the custom userdata, leaving out the defaults
+			// (which get stored in the cookie)
+			$userdata = array_diff_key($this->userdata, $this->defaults);
+
+			// Did we find any custom data?
+			if ( ! empty($userdata))
+			{
+				// Serialize the custom data array so we can store it
+				$set['user_data'] = $this->_serialize($userdata);
+			}
+
+			// Run the update query
+			// Any time we change the session id, it gets updated immediately,
+			// so our where clause below is always safe
+			$this->CI->db->update($this->sess_table_name, $set, array('session_id' => $this->userdata['session_id']));
+
+			// Clear dirty flag to prevent double updates
+			$this->data_dirty = FALSE;
+
+			log_message('debug', 'CI_Session Data Saved To DB');
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Generate a new session id
+	 *
+	 * @return	string	Hashed session id
+	 */
+	protected function _make_sess_id()
+	{
+		$new_sessid = '';
+		do
+		{
+			$new_sessid .= mt_rand(0, mt_getrandmax());
+		}
+		while (strlen($new_sessid) < 32);
+
+		// To make the session ID even more secure we'll combine it with the user's IP
+		$new_sessid .= $this->CI->input->ip_address();
+
+		// Turn it into a hash and return
+		return md5(uniqid($new_sessid, TRUE));
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Get the "now" time
+	 *
+	 * @return	int	 Time
+	 */
+	protected function _get_time()
+	{
+		if ($this->time_reference === 'local' OR $this->time_reference === date_default_timezone_get())
+		{
+			return time();
+		}
+
+		$datetime = new DateTime('now', new DateTimeZone($this->time_reference));
+		sscanf($datetime->format('j-n-Y G:i:s'), '%d-%d-%d %d:%d:%d', $day, $month, $year, $hour, $minute, $second);
+
+		return mktime($hour, $minute, $second, $month, $day, $year);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Write the session cookie
+	 *
+	 * @return	void
+	 */
+	protected function _set_cookie()
+	{
+		// Get userdata (only defaults if database)
+		$cookie_data = ($this->sess_use_database === TRUE)
+				? array_intersect_key($this->userdata, $this->defaults)
+				: $this->userdata;
+
+		// Serialize the userdata for the cookie
+		$cookie_data = $this->_serialize($cookie_data);
+
+		if ($this->sess_encrypt_cookie === TRUE)
+		{
+			$cookie_data = $this->CI->encrypt->encode($cookie_data);
+		}
+
+		// Require message authentication
+		$cookie_data .= hash_hmac('sha1', $cookie_data, $this->encryption_key);
+
+		$expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time();
+
+		// Set the cookie
+		$this->_setcookie($this->sess_cookie_name, $cookie_data, $expire, $this->cookie_path, $this->cookie_domain,
+			$this->cookie_secure, $this->cookie_httponly);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Set a cookie with the system
+	 *
+	 * This abstraction of the setcookie call allows overriding for unit testing
+	 *
+	 * @param	string	Cookie name
+	 * @param	string	Cookie value
+	 * @param	int	Expiration time
+	 * @param	string	Cookie path
+	 * @param	string	Cookie domain
+	 * @param	bool	Secure connection flag
+	 * @param	bool	HTTP protocol only flag
+	 * @return	void
+	 */
+	protected function _setcookie($name, $value = '', $expire = 0, $path = '', $domain = '', $secure = FALSE, $httponly = FALSE)
+	{
+		setcookie($name, $value, $expire, $path, $domain, $secure, $httponly);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Serialize an array
+	 *
+	 * This function first converts any slashes found in the array to a temporary
+	 * marker, so when it gets unserialized the slashes will be preserved
+	 *
+	 * @param	mixed	Data to serialize
+	 * @return	string	Serialized data
+	 */
+	protected function _serialize($data)
+	{
+		if (is_array($data))
+		{
+			array_walk_recursive($data, array(&$this, '_escape_slashes'));
+		}
+		elseif (is_string($data))
+		{
+			$data = str_replace('\\', '{{slash}}', $data);
+		}
+
+		return serialize($data);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Escape slashes
+	 *
+	 * This function converts any slashes found into a temporary marker
+	 *
+	 * @param	string	Value
+	 * @param	string	Key
+	 * @return	void
+	 */
+	protected function _escape_slashes(&$val, $key)
+	{
+		if (is_string($val))
+		{
+			$val = str_replace('\\', '{{slash}}', $val);
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Unserialize
+	 *
+	 * This function unserializes a data string, then converts any
+	 * temporary slash markers back to actual slashes
+	 *
+	 * @param	mixed	Data to unserialize
+	 * @return	mixed	Unserialized data
+	 */
+	protected function _unserialize($data)
+	{
+		$data = @unserialize(strip_slashes(trim($data)));
+
+		if (is_array($data))
+		{
+			array_walk_recursive($data, array(&$this, '_unescape_slashes'));
+			return $data;
+		}
+
+		return is_string($data) ? str_replace('{{slash}}', '\\', $data) : $data;
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Unescape slashes
+	 *
+	 * This function converts any slash markers back into actual slashes
+	 *
+	 * @param	string	Value
+	 * @param	string	Key
+	 * @return	void
+	 */
+	protected function _unescape_slashes(&$val, $key)
+	{
+		if (is_string($val))
+		{
+	 		$val= str_replace('{{slash}}', '\\', $val);
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Garbage collection
+	 *
+	 * This deletes expired session rows from database
+	 * if the probability percentage is met
+	 *
+	 * @return	void
+	 */
+	protected function _sess_gc()
+	{
+		if ($this->sess_use_database !== TRUE)
+		{
+			return;
+		}
+
+		$probability = ini_get('session.gc_probability');
+		$divisor = ini_get('session.gc_divisor');
+
+		srand(time());
+		if ((mt_rand(0, $divisor) / $divisor) < $probability)
+		{
+			$expire = $this->now - $this->sess_expiration;
+			$this->CI->db->delete($this->sess_table_name, 'last_activity < '.$expire);
+
+			log_message('debug', 'Session garbage collection performed.');
+		}
+	}
+
+}
+
+/* End of file Session_cookie.php */
+/* Location: ./system/libraries/Session/drivers/Session_cookie.php */
\ No newline at end of file
diff --git a/system/libraries/Session/drivers/Session_native.php b/system/libraries/Session/drivers/Session_native.php
new file mode 100755
index 000000000..da744f39b
--- /dev/null
+++ b/system/libraries/Session/drivers/Session_native.php
@@ -0,0 +1,241 @@
+<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst. It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+
+/**
+ * Native PHP session management driver
+ *
+ * This is the driver that uses the native PHP $_SESSION array through the Session driver library.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		EllisLab Dev Team
+ */
+class CI_Session_native extends CI_Session_driver {
+
+	/**
+	 * Initialize session driver object
+	 *
+	 * @return	void
+	 */
+	protected function initialize()
+	{
+		// Get config parameters
+		$config = array();
+		$prefs = array(
+			'sess_cookie_name',
+			'sess_expire_on_close',
+			'sess_expiration',
+			'sess_match_ip',
+			'sess_match_useragent',
+			'sess_time_to_update',
+			'cookie_prefix',
+			'cookie_path',
+			'cookie_domain',
+			'cookie_secure',
+			'cookie_httponly'
+		);
+
+		foreach ($prefs as $key)
+		{
+			$config[$key] = isset($this->_parent->params[$key])
+				? $this->_parent->params[$key]
+				: $this->CI->config->item($key);
+		}
+
+		// Set session name, if specified
+		if ($config['sess_cookie_name'])
+		{
+			// Differentiate name from cookie driver with '_id' suffix
+			$name = $config['sess_cookie_name'].'_id';
+			if ($config['cookie_prefix'])
+			{
+				// Prepend cookie prefix
+				$name = $config['cookie_prefix'].$name;
+			}
+			session_name($name);
+		}
+
+		// Set expiration, path, and domain
+		$expire = 7200;
+		$path = '/';
+		$domain = '';
+		$secure = (bool) $config['cookie_secure'];
+		$http_only = (bool) $config['cookie_httponly'];
+
+		if ($config['sess_expiration'] !== FALSE)
+		{
+			// Default to 2 years if expiration is "0"
+			$expire = ($config['sess_expiration'] == 0) ? (60*60*24*365*2) : $config['sess_expiration'];
+		}
+
+		if ($config['cookie_path'])
+		{
+			// Use specified path
+			$path = $config['cookie_path'];
+		}
+
+		if ($config['cookie_domain'])
+		{
+			// Use specified domain
+			$domain = $config['cookie_domain'];
+		}
+
+		session_set_cookie_params($config['sess_expire_on_close'] ? 0 : $expire, $path, $domain, $secure, $http_only);
+
+		// Start session
+		session_start();
+
+		// Check session expiration, ip, and agent
+		$now = time();
+		$destroy = FALSE;
+		if (isset($_SESSION['last_activity']) && (($_SESSION['last_activity'] + $expire) < $now OR $_SESSION['last_activity'] > $now))
+		{
+			// Expired - destroy
+			$destroy = TRUE;
+		}
+		elseif ($config['sess_match_ip'] === TRUE && isset($_SESSION['ip_address'])
+			&& $_SESSION['ip_address'] !== $this->CI->input->ip_address())
+		{
+			// IP doesn't match - destroy
+			$destroy = TRUE;
+		}
+		elseif ($config['sess_match_useragent'] === TRUE && isset($_SESSION['user_agent'])
+			&& $_SESSION['user_agent'] !== trim(substr($this->CI->input->user_agent(), 0, 50)))
+		{
+			// Agent doesn't match - destroy
+			$destroy = TRUE;
+		}
+
+		// Destroy expired or invalid session
+		if ($destroy)
+		{
+			// Clear old session and start new
+			$this->sess_destroy();
+			session_start();
+		}
+
+		// Check for update time
+		if ($config['sess_time_to_update'] && isset($_SESSION['last_activity'])
+			&& ($_SESSION['last_activity'] + $config['sess_time_to_update']) < $now)
+		{
+			// Changing the session ID amidst a series of AJAX calls causes problems
+			if( ! $this->CI->input->is_ajax_request())
+			{
+				// Regenerate ID, but don't destroy session
+				$this->sess_regenerate(FALSE);
+			}
+		}
+
+		// Set activity time
+		$_SESSION['last_activity'] = $now;
+
+		// Set matching values as required
+		if ($config['sess_match_ip'] === TRUE && ! isset($_SESSION['ip_address']))
+		{
+			// Store user IP address
+			$_SESSION['ip_address'] = $this->CI->input->ip_address();
+		}
+
+		if ($config['sess_match_useragent'] === TRUE && ! isset($_SESSION['user_agent']))
+		{
+			// Store user agent string
+			$_SESSION['user_agent'] = trim(substr($this->CI->input->user_agent(), 0, 50));
+		}
+
+		// Make session ID available
+		$_SESSION['session_id'] = session_id();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Save the session data
+	 *
+	 * @return	void
+	 */
+	public function sess_save()
+	{
+		// Nothing to do - changes to $_SESSION are automatically saved
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Destroy the current session
+	 *
+	 * @return	void
+	 */
+	public function sess_destroy()
+	{
+		// Cleanup session
+		$_SESSION = array();
+		$name = session_name();
+		if (isset($_COOKIE[$name]))
+		{
+			// Clear session cookie
+			$params = session_get_cookie_params();
+			setcookie($name, '', time() - 42000, $params['path'], $params['domain'], $params['secure'], $params['httponly']);
+			unset($_COOKIE[$name]);
+		}
+		session_destroy();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Regenerate the current session
+	 *
+	 * Regenerate the session id
+	 *
+	 * @param	bool	Destroy session data flag (default: FALSE)
+	 * @return	void
+	 */
+	public function sess_regenerate($destroy = FALSE)
+	{
+		// Just regenerate id, passing destroy flag
+		session_regenerate_id($destroy);
+		$_SESSION['session_id'] = session_id();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Get a reference to user data array
+	 *
+	 * @return	array	Reference to userdata
+	 */
+	public function &get_userdata()
+	{
+		// Just return reference to $_SESSION
+		return $_SESSION;
+	}
+
+}
+
+/* End of file Session_native.php */
+/* Location: ./system/libraries/Session/drivers/Session_native.php */
\ No newline at end of file
diff --git a/system/libraries/Trackback.php b/system/libraries/Trackback.php
index 9a680dc2a..7bd7cba04 100644
--- a/system/libraries/Trackback.php
+++ b/system/libraries/Trackback.php
@@ -45,6 +45,11 @@ class CI_Trackback {
 	public $response		= '';
 	public $error_msg		= array();
 
+	/**
+	 * Constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		log_message('debug', 'Trackback Class Initialized');
diff --git a/system/libraries/Unit_test.php b/system/libraries/Unit_test.php
index 70ad8dc41..7b99dee0d 100644
--- a/system/libraries/Unit_test.php
+++ b/system/libraries/Unit_test.php
@@ -38,13 +38,18 @@
  */
 class CI_Unit_test {
 
-	public $active					= TRUE;
-	public $results				= array();
-	public $strict					= FALSE;
-	protected $_template				= NULL;
-	protected $_template_rows			= NULL;
+	public $active			= TRUE;
+	public $results			= array();
+	public $strict			= FALSE;
+	protected $_template		= NULL;
+	protected $_template_rows	= NULL;
 	protected $_test_items_visible	= array();
 
+	/**
+	 * Constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		// These are the default items visible when a test is run.
@@ -86,9 +91,10 @@ class CI_Unit_test {
 	 *
 	 * Runs the supplied tests
 	 *
-	 * @param	mixed
-	 * @param	mixed
-	 * @param	string
+	 * @param	mixed	$test
+	 * @param	mixed	$expected = TRUE
+	 * @param	string	$test_name = 'undefined'
+	 * @param	string	$notes = ''
 	 * @return	string
 	 */
 	public function run($test, $expected = TRUE, $test_name = 'undefined', $notes = '')
@@ -134,6 +140,7 @@ class CI_Unit_test {
 	 *
 	 * Displays a table with the test data
 	 *
+	 * @param	array	 $result = array()
 	 * @return	string
 	 */
 	public function report($result = array())
@@ -213,6 +220,7 @@ class CI_Unit_test {
 	 *
 	 * Returns the raw result data
 	 *
+	 * @param	array	$results = array()
 	 * @return	array
 	 */
 	public function result($results = array())
@@ -240,6 +248,11 @@ class CI_Unit_test {
 				{
 					foreach ($val as $k => $v)
 					{
+						if ( ! in_array($k, $this->_test_items_visible))
+						{
+							continue;
+						}
+
 						if (FALSE !== ($line = $CI->lang->line(strtolower('ut_'.$v))))
 						{
 							$v = $line;
@@ -340,14 +353,22 @@ class CI_Unit_test {
 }
 
 /**
- * Helper functions to test boolean true/false
+ * Helper function to test boolean TRUE
  *
+ * @param	mixed	$test
  * @return	bool
  */
 function is_true($test)
 {
 	return ($test === TRUE);
 }
+
+/**
+ * Helper function to test boolean FALSE
+ *
+ * @param	mixed	$test
+ * @return	bool
+ */
 function is_false($test)
 {
 	return ($test === FALSE);
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index d381440cd..76bbc244e 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -154,6 +154,7 @@ class CI_Upload {
 	/**
 	 * Perform the file upload
 	 *
+	 * @param	string	$field = 'userfile'
 	 * @return	bool
 	 */
 	public function do_upload($field = 'userfile')
@@ -790,7 +791,8 @@ class CI_Upload {
 	/**
 	 * Limit the File Name Length
 	 *
-	 * @param	string
+	 * @param	string	$filename
+	 * @param	int	$length
 	 * @return	string
 	 */
 	public function limit_filename_length($filename, $length)
diff --git a/system/libraries/Xmlrpc.php b/system/libraries/Xmlrpc.php
index cbb91c40a..3ed050a2e 100644..100755
--- a/system/libraries/Xmlrpc.php
+++ b/system/libraries/Xmlrpc.php
@@ -170,8 +170,10 @@ class CI_Xmlrpc {
 	/**
 	 * Parse server URL
 	 *
-	 * @param	string	url
-	 * @param	int	port
+	 * @param	string	$url
+	 * @param	int	$port = 80
+	 * @param	string	$proxy = FALSE
+	 * @param	int	$proxy_port = 8080
 	 * @return	void
 	 */
 	public function server($url, $port = 80, $proxy = FALSE, $proxy_port = 8080)
@@ -395,9 +397,11 @@ class XML_RPC_Client extends CI_Xmlrpc
 	/**
 	 * Constructor
 	 *
-	 * @param	string
-	 * @param	object
-	 * @param	int
+	 * @param	string	$path
+	 * @param	object	$server
+	 * @param	int	$port = 80
+	 * @param	string	$proxy = FALSE
+	 * @param	int	$proxy_port = 8080
 	 * @return	void
 	 */
 	public function __construct($path, $server, $port = 80, $proxy = FALSE, $proxy_port = 8080)
@@ -1317,15 +1321,15 @@ class XML_RPC_Values extends CI_Xmlrpc
 		{
 			$type = $type === '' ? 'string' : $type;
 
-			if ($this->xmlrpcTypes[$type] === 1)
+			if ($this->xmlrpcTypes[$type] == 1)
 			{
 				$this->addScalar($val,$type);
 			}
-			elseif ($this->xmlrpcTypes[$type] === 2)
+			elseif ($this->xmlrpcTypes[$type] == 2)
 			{
 				$this->addArray($val);
 			}
-			elseif ($this->xmlrpcTypes[$type] === 3)
+			elseif ($this->xmlrpcTypes[$type] == 3)
 			{
 				$this->addStruct($val);
 			}
@@ -1351,7 +1355,7 @@ class XML_RPC_Values extends CI_Xmlrpc
 			return 0;
 		}
 
-		if ($typeof !== 1)
+		if ($typeof != 1)
 		{
 			echo '<strong>XML_RPC_Values</strong>: not a scalar type (${typeof})<br />';
 			return 0;
@@ -1359,7 +1363,7 @@ class XML_RPC_Values extends CI_Xmlrpc
 
 		if ($type === $this->xmlrpcBoolean)
 		{
-			$val = (int) (strcasecmp($val,'true') === 0 OR $val === 1 OR ($val === TRUE && strcasecmp($val, 'false')));
+			$val = (int) (strcasecmp($val, 'true') === 0 OR $val === 1 OR ($val === TRUE && strcasecmp($val, 'false')));
 		}
 
 		if ($this->mytype === 2)
diff --git a/system/libraries/javascript/Jquery.php b/system/libraries/javascript/Jquery.php
index 44c16b578..8739d141f 100644
--- a/system/libraries/javascript/Jquery.php
+++ b/system/libraries/javascript/Jquery.php
@@ -34,7 +34,6 @@
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/libraries/javascript.html
  */
-
 class CI_Jquery extends CI_Javascript {
 
 	protected $_javascript_folder = 'js';
@@ -45,6 +44,12 @@ class CI_Jquery extends CI_Javascript {
 	public $jquery_table_sorter_pager_active = FALSE;
 	public $jquery_ajax_img = '';
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array	$params
+	 * @return	void
+	 */
 	public function __construct($params)
 	{
 		$this->CI =& get_instance();
@@ -101,15 +106,12 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * @param	string	The element to attach the event to
 	 * @param	string	The code to execute
-	 * @param	boolean	whether or not to return false
+	 * @param	bool	whether or not to return false
 	 * @return	string
 	 */
 	protected function _click($element = 'this', $js = '', $ret_false = TRUE)
 	{
-		if ( ! is_array($js))
-		{
-			$js = array($js);
-		}
+		is_array($js) OR $js = array($js);
 
 		if ($ret_false)
 		{
@@ -307,11 +309,10 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs script directly
 	 *
-	 * @param	string	The element to attach the event to
-	 * @param	string	The code to execute
-	 * @return	string
+	 * @param	array	$array_js = array()
+	 * @return	void
 	 */
-	protected function _output($array_js = '')
+	protected function _output($array_js = array())
 	{
 		if ( ! is_array($array_js))
 		{
@@ -381,10 +382,11 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery addClass event
 	 *
-	 * @param	string	- element
+	 * @param	string	$element = 'this'
+	 * @param	string	$class = ''
 	 * @return	string
 	 */
-	protected function _addClass($element = 'this', $class='')
+	protected function _addClass($element = 'this', $class = '')
 	{
 		$element = $this->_prep_element($element);
 		return '$('.$element.').addClass("'.$class.'");';
@@ -397,9 +399,10 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery animate event
 	 *
-	 * @param	string	- element
-	 * @param	string	- One of 'slow', 'normal', 'fast', or time in milliseconds
-	 * @param	string	- Javascript callback function
+	 * @param	string	$element = 'this'
+	 * @param	array	$params = array()
+	 * @param	string	$speed = ''		'slow', 'normal', 'fast', or time in milliseconds
+	 * @param	string	$extra = ''
 	 * @return	string
 	 */
 	protected function _animate($element = 'this', $params = array(), $speed = '', $extra = '')
@@ -511,10 +514,11 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery remove class event
 	 *
-	 * @param	string	- element
+	 * @param	string	$element = 'this'
+	 * @param	string	$class = ''
 	 * @return	string
 	 */
-	protected function _removeClass($element = 'this', $class='')
+	protected function _removeClass($element = 'this', $class = '')
 	{
 		$element = $this->_prep_element($element);
 		return '$('.$element.').removeClass("'.$class.'");';
@@ -618,10 +622,11 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs a jQuery toggle class event
 	 *
-	 * @param	string	- element
+	 * @param	string	$element = 'this'
+	 * @param	string	$class = ''
 	 * @return	string
 	 */
-	protected function _toggleClass($element = 'this', $class='')
+	protected function _toggleClass($element = 'this', $class = '')
 	{
 		$element = $this->_prep_element($element);
 		return '$('.$element.').toggleClass("'.$class.'");';
@@ -703,8 +708,9 @@ class CI_Jquery extends CI_Javascript {
 	/**
 	 * Zebra tables
 	 *
-	 * @param	string	table name
-	 * @param	string	plugin location
+	 * @param	string	$class = ''
+	 * @param	string	$odd = 'odd'
+	 * @param	string	$hover = ''
 	 * @return	string
 	 */
 	protected function _zebraTables($class = '', $odd = 'odd', $hover = '')
@@ -731,7 +737,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * http://www.malsup.com/jquery/corner/
 	 *
-	 * @param	string	target
+	 * @param	string	$element = ''
+	 * @param	string	$corner_style = ''
 	 * @return	string
 	 */
 	public function corner($element = '', $corner_style = '')
@@ -750,10 +757,12 @@ class CI_Jquery extends CI_Javascript {
 	// --------------------------------------------------------------------
 
 	/**
-	 * modal window
+	 * Modal window
 	 *
 	 * Load a thickbox modal window
 	 *
+	 * @param	string	$src
+	 * @param	bool	$relative = FALSE
 	 * @return	void
 	 */
 	public function modal($src, $relative = FALSE)
@@ -768,6 +777,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Load an Effect library
 	 *
+	 * @param	string	$src
+	 * @param	bool	$relative = FALSE
 	 * @return	void
 	 */
 	public function effect($src, $relative = FALSE)
@@ -782,6 +793,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Load a plugin library
 	 *
+	 * @param	string	$src
+	 * @param	bool	$relative = FALSE
 	 * @return	void
 	 */
 	public function plugin($src, $relative = FALSE)
@@ -796,12 +809,15 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Load a user interface library
 	 *
+	 * @param	string	$src
+	 * @param	bool	$relative = FALSE
 	 * @return	void
 	 */
 	public function ui($src, $relative = FALSE)
 	{
 		$this->jquery_code_for_load[] = $this->external($src, $relative);
 	}
+
 	// --------------------------------------------------------------------
 
 	/**
@@ -809,11 +825,12 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Creates a jQuery sortable
 	 *
-	 * @return	void
+	 * @param	string	$element
+	 * @param	array	$options = array()
+	 * @return	string
 	 */
 	public function sortable($element, $options = array())
 	{
-
 		if (count($options) > 0)
 		{
 			$sort_options = array();
@@ -880,7 +897,9 @@ class CI_Jquery extends CI_Javascript {
 	 * As events are specified, they are stored in an array
 	 * This funciton compiles them all for output on a page
 	 *
-	 * @return	string
+	 * @param	string	$view_var = 'script_foot'
+	 * @param	bool	$script_tags = TRUE
+	 * @return	void
 	 */
 	protected function _compile($view_var = 'script_foot', $script_tags = TRUE)
 	{
@@ -902,7 +921,6 @@ class CI_Jquery extends CI_Javascript {
 		$output = ($script_tags === FALSE) ? $script : $this->inline($script);
 
 		$this->CI->load->vars(array($view_var => $output));
-
 	}
 
 	// --------------------------------------------------------------------
@@ -926,14 +944,12 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * A wrapper for writing document.ready()
 	 *
-	 * @return	string
+	 * @param	array	$js
+	 * @return	void
 	 */
 	protected function _document_ready($js)
 	{
-		if ( ! is_array($js))
-		{
-			$js = array($js);
-		}
+		is_array($js) OR $js = array($js);
 
 		foreach ($js as $script)
 		{
@@ -948,7 +964,8 @@ class CI_Jquery extends CI_Javascript {
 	 *
 	 * Outputs the script tag that loads the jquery.js file into an HTML document
 	 *
-	 * @param	string
+	 * @param	string	$library_src = ''
+	 * @param	bool	$relative = FALSE
 	 * @return	string
 	 */
 	public function script($library_src = '', $relative = FALSE)