Merge branch 'develop' of github.com:EllisLab/CodeIgniter into feature/exit-status

43 files changed, 422 insertions, 341 deletions

diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index 13826c328..5a872ef21 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -58,7 +58,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  *  Load the framework constants
  * ------------------------------------------------------
  */
-	if (defined('ENVIRONMENT') && file_exists(APPPATH.'config/'.ENVIRONMENT.'/constants.php'))
+	if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/constants.php'))
 	{
 		require(APPPATH.'config/'.ENVIRONMENT.'/constants.php');
 	}
@@ -263,7 +263,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 	$class  = $RTR->fetch_class();
 	$method = $RTR->fetch_method();
 
-	if ( ! class_exists($class) OR $method[0] === '_' OR method_exists('CI_Controller', $method))
+	if ( ! class_exists($class, FALSE) OR $method[0] === '_' OR method_exists('CI_Controller', $method))
 	{
 		if ( ! empty($RTR->routes['404_override']))
 		{
@@ -272,7 +272,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 				$method = 'index';
 			}
 
-			if ( ! class_exists($class))
+			if ( ! class_exists($class, FALSE))
 			{
 				if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
 				{
@@ -310,7 +310,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
 				$method = 'index';
 			}
 
-			if ( ! class_exists($class))
+			if ( ! class_exists($class, FALSE))
 			{
 				if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
 				{
diff --git a/system/core/Common.php b/system/core/Common.php
index d6387209b..3cd97dc2e 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -150,7 +150,7 @@ if ( ! function_exists('load_class'))
 			{
 				$name = $prefix.$class;
 
-				if (class_exists($name) === FALSE)
+				if (class_exists($name, FALSE) === FALSE)
 				{
 					require_once($path.$directory.'/'.$class.'.php');
 				}
@@ -164,7 +164,7 @@ if ( ! function_exists('load_class'))
 		{
 			$name = config_item('subclass_prefix').$class;
 
-			if (class_exists($name) === FALSE)
+			if (class_exists($name, FALSE) === FALSE)
 			{
 				require_once(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.'.php');
 			}
@@ -243,7 +243,7 @@ if ( ! function_exists('get_config'))
 		}
 
 		// Is the config file in the environment folder?
-		if (defined('ENVIRONMENT') && file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config.php'))
+		if (file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config.php'))
 		{
 			require($file_path);
 		}
@@ -320,11 +320,11 @@ if ( ! function_exists('get_mimes'))
 	{
 		static $_mimes = array();
 
-		if (defined('ENVIRONMENT') && is_file(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
+		if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
 		{
 			$_mimes = include(APPPATH.'config/'.ENVIRONMENT.'/mimes.php');
 		}
-		elseif (is_file(APPPATH.'config/mimes.php'))
+		elseif (file_exists(APPPATH.'config/mimes.php'))
 		{
 			$_mimes = include(APPPATH.'config/mimes.php');
 		}
@@ -347,7 +347,7 @@ if ( ! function_exists('is_https'))
 	 */
 	function is_https()
 	{
-		return ( ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off');
+		return (isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) === 'on');
 	}
 }
 
@@ -429,7 +429,7 @@ if ( ! function_exists('log_message'))
 	function log_message($level = 'error', $message, $php_error = FALSE)
 	{
 		static $_log, $_log_threshold;
-		
+
 		if ($_log_threshold === NULL)
 		{
 			$_log_threshold = config_item('log_threshold');
@@ -444,7 +444,7 @@ if ( ! function_exists('log_message'))
 		{
 			$_log =& load_class('Log', 'core');
 		}
-		
+
 		$_log->write_log($level, $message, $php_error);
 	}
 }
diff --git a/system/core/Config.php b/system/core/Config.php
index 0160d1a15..7e64444bc 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -106,13 +106,9 @@ class CI_Config {
 		$file = ($file === '') ? 'config' : str_replace('.php', '', $file);
 		$found = $loaded = FALSE;
 
-		$check_locations = defined('ENVIRONMENT')
-			? array(ENVIRONMENT.'/'.$file, $file)
-			: array($file);
-
 		foreach ($this->_config_paths as $path)
 		{
-			foreach ($check_locations as $location)
+			foreach (array(ENVIRONMENT.'/'.$file, $file) as $location)
 			{
 				$file_path = $path.'config/'.$location.'.php';
 
diff --git a/system/core/Hooks.php b/system/core/Hooks.php
index 2cb416c0c..b3b111991 100644
--- a/system/core/Hooks.php
+++ b/system/core/Hooks.php
@@ -81,11 +81,12 @@ class CI_Hooks {
 		}
 
 		// Grab the "hooks" definition file.
-		if (defined('ENVIRONMENT') && is_file(APPPATH.'config/'.ENVIRONMENT.'/hooks.php'))
+		if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/hooks.php'))
 		{
 			include(APPPATH.'config/'.ENVIRONMENT.'/hooks.php');
 		}
-		elseif (is_file(APPPATH.'config/hooks.php'))
+
+		if (file_exists(APPPATH.'config/hooks.php'))
 		{
 			include(APPPATH.'config/hooks.php');
 		}
@@ -194,7 +195,7 @@ class CI_Hooks {
 		// Call the requested class and/or function
 		if ($class !== FALSE)
 		{
-			if ( ! class_exists($class))
+			if ( ! class_exists($class, FALSE))
 			{
 				require($filepath);
 			}
diff --git a/system/core/Input.php b/system/core/Input.php
index 8f37e4464..904f4d6e9 100644
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -720,9 +720,9 @@ class CI_Input {
 		}
 
 		// Standardize newlines if needed
-		if ($this->_standardize_newlines === TRUE && strpos($str, "\r") !== FALSE)
+		if ($this->_standardize_newlines === TRUE)
 		{
-			return str_replace(array("\r\n", "\r", "\r\n\n"), PHP_EOL, $str);
+			return preg_replace('/(?:\r\n|[\r\n])/', PHP_EOL, $str);
 		}
 
 		return $str;
diff --git a/system/core/Loader.php b/system/core/Loader.php
index 1ad07f1fa..6e5b58ba7 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -97,13 +97,6 @@ class CI_Loader {
 	protected $_ci_classes =	array();
 
 	/**
-	 * List of loaded files
-	 *
-	 * @var	array
-	 */
-	protected $_ci_loaded_files =	array();
-
-	/**
 	 * List of loaded models
 	 *
 	 * @var	array
@@ -277,7 +270,7 @@ class CI_Loader {
 				continue;
 			}
 
-			if ($db_conn !== FALSE && ! class_exists('CI_DB'))
+			if ($db_conn !== FALSE && ! class_exists('CI_DB', FALSE))
 			{
 				if ($db_conn === TRUE)
 				{
@@ -287,7 +280,7 @@ class CI_Loader {
 				$CI->load->database($db_conn, FALSE, TRUE);
 			}
 
-			if ( ! class_exists('CI_Model'))
+			if ( ! class_exists('CI_Model', FALSE))
 			{
 				load_class('Model', 'core');
 			}
@@ -943,7 +936,6 @@ class CI_Loader {
 
 		// Was the path included with the class name?
 		// We look for a slash to determine this
-		$subdir = '';
 		if (($last_slash = strrpos($class, '/')) !== FALSE)
 		{
 			// Extract the path
@@ -952,108 +944,92 @@ class CI_Loader {
 			// Get the filename from the path
 			$class = substr($class, $last_slash);
 		}
+		else
+		{
+			$subdir = '';
+		}
+
+		$class = ucfirst($class);
+		$subclass = APPPATH.'libraries/'.$subdir.config_item('subclass_prefix').$class.'.php';
 
-		// We'll test for both lowercase and capitalized versions of the file name
-		foreach (array(ucfirst($class), strtolower($class)) as $class)
+		// Is this a class extension request?
+		if (file_exists($subclass))
 		{
-			$subclass = APPPATH.'libraries/'.$subdir.config_item('subclass_prefix').$class.'.php';
+			$baseclass = BASEPATH.'libraries/'.$class.'.php';
 
-			// Is this a class extension request?
-			if (file_exists($subclass))
+			if ( ! file_exists($baseclass))
 			{
-				$baseclass = BASEPATH.'libraries/'.ucfirst($class).'.php';
-
-				if ( ! file_exists($baseclass))
-				{
-					log_message('error', 'Unable to load the requested class: '.$class);
-					show_error('Unable to load the requested class: '.$class);
-				}
+				log_message('error', 'Unable to load the requested class: '.$class);
+				show_error('Unable to load the requested class: '.$class);
+			}
 
-				// Safety: Was the class already loaded by a previous call?
-				if (in_array($subclass, $this->_ci_loaded_files))
+			// Safety: Was the class already loaded by a previous call?
+			if (class_exists(config_item('subclass_prefix').$class, FALSE))
+			{
+				// Before we deem this to be a duplicate request, let's see
+				// if a custom object name is being supplied. If so, we'll
+				// return a new instance of the object
+				if ($object_name !== NULL)
 				{
-					// Before we deem this to be a duplicate request, let's see
-					// if a custom object name is being supplied. If so, we'll
-					// return a new instance of the object
-					if ($object_name !== NULL)
+					$CI =& get_instance();
+					if ( ! isset($CI->$object_name))
 					{
-						$CI =& get_instance();
-						if ( ! isset($CI->$object_name))
-						{
-							return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);
-						}
+						return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);
 					}
-
-					$is_duplicate = TRUE;
-					log_message('debug', $class.' class already loaded. Second attempt ignored.');
-					return;
 				}
 
-				include_once($baseclass);
-				include_once($subclass);
-				$this->_ci_loaded_files[] = $subclass;
-
-				return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);
+				log_message('debug', $class.' class already loaded. Second attempt ignored.');
+				return;
 			}
 
-			// Lets search for the requested library file and load it.
-			$is_duplicate = FALSE;
-			foreach ($this->_ci_library_paths as $path)
-			{
-				$filepath = $path.'libraries/'.$subdir.$class.'.php';
+			include_once($baseclass);
+			include_once($subclass);
 
-				// Does the file exist? No? Bummer...
-				if ( ! file_exists($filepath))
-				{
-					continue;
-				}
+			return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);
+		}
+
+		// Let's search for the requested library file and load it.
+		foreach ($this->_ci_library_paths as $path)
+		{
+			$filepath = $path.'libraries/'.$subdir.$class.'.php';
 
-				// Safety: Was the class already loaded by a previous call?
-				if (in_array($filepath, $this->_ci_loaded_files))
+			// Safety: Was the class already loaded by a previous call?
+			if (class_exists($class, FALSE))
+			{
+				// Before we deem this to be a duplicate request, let's see
+				// if a custom object name is being supplied. If so, we'll
+				// return a new instance of the object
+				if ($object_name !== NULL)
 				{
-					// Before we deem this to be a duplicate request, let's see
-					// if a custom object name is being supplied. If so, we'll
-					// return a new instance of the object
-					if ($object_name !== NULL)
+					$CI =& get_instance();
+					if ( ! isset($CI->$object_name))
 					{
-						$CI =& get_instance();
-						if ( ! isset($CI->$object_name))
-						{
-							return $this->_ci_init_class($class, '', $params, $object_name);
-						}
+						return $this->_ci_init_class($class, '', $params, $object_name);
 					}
-
-					$is_duplicate = TRUE;
-					log_message('debug', $class.' class already loaded. Second attempt ignored.');
-					return;
 				}
 
-				include_once($filepath);
-				$this->_ci_loaded_files[] = $filepath;
-				return $this->_ci_init_class($class, '', $params, $object_name);
+				log_message('debug', $class.' class already loaded. Second attempt ignored.');
+				return;
+			}
+			// Does the file exist? No? Bummer...
+			elseif ( ! file_exists($filepath))
+			{
+				continue;
 			}
-		} // END FOREACH
+
+			include_once($filepath);
+			return $this->_ci_init_class($class, '', $params, $object_name);
+		}
 
 		// 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, $object_name);
-		}
-		elseif (ucfirst($subdir) != $subdir)
-		{
-			// Lowercase subdir failed - retry capitalized
-			$path = ucfirst($subdir).$class;
-			return $this->_ci_load_class($path, $params, $object_name);
+			return $this->_ci_load_class($class.'/'.$class, $params, $object_name);
 		}
 
 		// If we got this far we were unable to find the requested class.
-		// We do not issue errors if the load call failed due to a duplicate request
-		if ($is_duplicate === FALSE)
-		{
-			log_message('error', 'Unable to load the requested class: '.$class);
-			show_error('Unable to load the requested class: '.$class);
-		}
+		log_message('error', 'Unable to load the requested class: '.$class);
+		show_error('Unable to load the requested class: '.$class);
 	}
 
 	// --------------------------------------------------------------------
@@ -1089,12 +1065,12 @@ class CI_Loader {
 					// We test for both uppercase and lowercase, for servers that
 					// are case-sensitive with regard to file names. Check for environment
 					// first, global next
-					if (defined('ENVIRONMENT') && file_exists($path.'config/'.ENVIRONMENT.'/'.strtolower($class).'.php'))
+					if (file_exists($path.'config/'.ENVIRONMENT.'/'.strtolower($class).'.php'))
 					{
 						include($path.'config/'.ENVIRONMENT.'/'.strtolower($class).'.php');
 						break;
 					}
-					elseif (defined('ENVIRONMENT') && file_exists($path.'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).'.php'))
+					elseif (file_exists($path.'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).'.php'))
 					{
 						include($path.'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).'.php');
 						break;
@@ -1115,11 +1091,11 @@ class CI_Loader {
 
 		if ($prefix === '')
 		{
-			if (class_exists('CI_'.$class))
+			if (class_exists('CI_'.$class, FALSE))
 			{
 				$name = 'CI_'.$class;
 			}
-			elseif (class_exists(config_item('subclass_prefix').$class))
+			elseif (class_exists(config_item('subclass_prefix').$class, FALSE))
 			{
 				$name = config_item('subclass_prefix').$class;
 			}
@@ -1134,7 +1110,7 @@ class CI_Loader {
 		}
 
 		// Is the class name valid?
-		if ( ! class_exists($name))
+		if ( ! class_exists($name, FALSE))
 		{
 			log_message('error', 'Non-existent class: '.$name);
 			show_error('Non-existent class: '.$name);
@@ -1180,7 +1156,7 @@ class CI_Loader {
 	 */
 	protected function _ci_autoloader()
 	{
-		if (defined('ENVIRONMENT') && file_exists(APPPATH.'config/'.ENVIRONMENT.'/autoload.php'))
+		if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/autoload.php'))
 		{
 			include(APPPATH.'config/'.ENVIRONMENT.'/autoload.php');
 		}
diff --git a/system/core/Log.php b/system/core/Log.php
index cd3c17e1e..a84d3dc22 100644
--- a/system/core/Log.php
+++ b/system/core/Log.php
@@ -73,6 +73,13 @@ class CI_Log {
 	protected $_date_fmt		= 'Y-m-d H:i:s';
 
 	/**
+	 * Filename extension
+	 *
+	 * @var	string
+	 */
+	protected $_file_ext;
+
+	/**
 	 * Whether or not the logger can write to the log files
 	 *
 	 * @var bool
@@ -86,8 +93,10 @@ class CI_Log {
 	 */
 	protected $_levels		= array('ERROR' => 1, 'DEBUG' => 2, 'INFO' => 3, 'ALL' => 4);
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * Initialize Logging class
+	 * Class constructor
 	 *
 	 * @return	void
 	 */
@@ -96,6 +105,8 @@ class CI_Log {
 		$config =& get_config();
 
 		$this->_log_path = ($config['log_path'] !== '') ? $config['log_path'] : APPPATH.'logs/';
+		$this->_file_ext = (isset($config['log_file_extension']) && $config['log_file_extension'] !== '')
+			? ltrim($config['log_file_extension'], '.') : 'php';
 
 		file_exists($this->_log_path) OR mkdir($this->_log_path, DIR_WRITE_MODE, TRUE);
 
@@ -147,13 +158,17 @@ class CI_Log {
 			return FALSE;
 		}
 
-		$filepath = $this->_log_path.'log-'.date('Y-m-d').'.php';
-		$message  = '';
+		$filepath = $this->_log_path.'log-'.date('Y-m-d').'.'.$this->_file_ext;
+		$message = '';
 
 		if ( ! file_exists($filepath))
 		{
 			$newfile = TRUE;
-			$message .= '<'."?php defined('BASEPATH') OR exit('No direct script access allowed'); ?".">\n\n";
+			// Only add protection to php files
+			if ($this->_file_ext === 'php')
+			{
+				$message .= "<?php defined('BASEPATH') OR exit('No direct script access allowed'); ?>\n\n";
+			}
 		}
 
 		if ( ! $fp = @fopen($filepath, FOPEN_WRITE_CREATE))
@@ -179,4 +194,4 @@ class CI_Log {
 }
 
 /* End of file Log.php */
-/* Location: ./system/libraries/Log.php */
\ No newline at end of file
+/* Location: ./system/core/Log.php */
\ No newline at end of file
diff --git a/system/core/Output.php b/system/core/Output.php
index 7898d1972..d4abe871d 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -395,7 +395,7 @@ class CI_Output {
 		global $BM, $CFG;
 
 		// Grab the super object if we can.
-		if (class_exists('CI_Controller'))
+		if (class_exists('CI_Controller', FALSE))
 		{
 			$CI =& get_instance();
 		}
diff --git a/system/core/Router.php b/system/core/Router.php
index f284e29cc..bb0ce16bd 100644
--- a/system/core/Router.php
+++ b/system/core/Router.php
@@ -133,13 +133,14 @@ class CI_Router {
 		}
 
 		// Load the routes.php file.
-		if (defined('ENVIRONMENT') && is_file(APPPATH.'config/'.ENVIRONMENT.'/routes.php'))
+		if (file_exists(APPPATH.'config/routes.php'))
 		{
-			include(APPPATH.'config/'.ENVIRONMENT.'/routes.php');
+			include(APPPATH.'config/routes.php');
 		}
-		elseif (is_file(APPPATH.'config/routes.php'))
+
+		if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/routes.php'))
 		{
-			include(APPPATH.'config/routes.php');
+			include(APPPATH.'config/'.ENVIRONMENT.'/routes.php');
 		}
 
 		$this->routes = (empty($route) OR ! is_array($route)) ? array() : $route;
diff --git a/system/core/Security.php b/system/core/Security.php
index a6cd14a5f..7aae54efc 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -576,7 +576,15 @@ class CI_Security {
 		}
 
 		$str = remove_invisible_characters($str, FALSE);
-		return stripslashes(str_replace($bad, '', $str));
+
+		do
+		{
+			$old = $str;
+			$str = str_replace($bad, '', $str);
+		}
+		while ($old !== $str);
+
+		return stripslashes($str);
 	}
 
 	// ----------------------------------------------------------------
diff --git a/system/core/URI.php b/system/core/URI.php
index 9b31a646b..b2286f032 100644
--- a/system/core/URI.php
+++ b/system/core/URI.php
@@ -126,7 +126,7 @@ class CI_URI {
 				return;
 			}
 
-			// As a last ditch effort lets try using the $_GET array
+			// As a last ditch effort let's try using the $_GET array
 			if (is_array($_GET) && count($_GET) === 1 && trim(key($_GET), '/') !== '')
 			{
 				$this->_set_uri_string(key($_GET));
diff --git a/system/database/DB.php b/system/database/DB.php
index f94685c51..83d973304 100644
--- a/system/database/DB.php
+++ b/system/database/DB.php
@@ -43,7 +43,7 @@ function &DB($params = '', $query_builder_override = NULL)
 	if (is_string($params) && strpos($params, '://') === FALSE)
 	{
 		// Is the config file in the environment folder?
-		if (( ! defined('ENVIRONMENT') OR ! file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/database.php'))
+		if ( ! file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/database.php')
 			&& ! file_exists($file_path = APPPATH.'config/database.php'))
 		{
 			show_error('The configuration file database.php does not exist.');
@@ -149,7 +149,7 @@ function &DB($params = '', $query_builder_override = NULL)
 	if ( ! isset($query_builder) OR $query_builder === TRUE)
 	{
 		require_once(BASEPATH.'database/DB_query_builder.php');
-		if ( ! class_exists('CI_DB'))
+		if ( ! class_exists('CI_DB', FALSE))
 		{
 			/**
 			 * CI_DB
@@ -162,7 +162,7 @@ function &DB($params = '', $query_builder_override = NULL)
 			class CI_DB extends CI_DB_query_builder { }
 		}
 	}
-	elseif ( ! class_exists('CI_DB'))
+	elseif ( ! class_exists('CI_DB', FALSE))
 	{
 		/**
 	 	 * @ignore
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index cb2ef4ac8..6ae1d524d 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -625,7 +625,7 @@ abstract class CI_DB_driver {
 				// if transactions are enabled. If we don't call this here
 				// the error message will trigger an exit, causing the
 				// transactions to remain in limbo.
-				$this->trans_complete();
+				$this->_trans_depth > 0 && $this->trans_complete();
 
 				// Display errors
 				return $this->display_error(array('Error Number: '.$error['code'], $error['message'], $sql));
@@ -1560,7 +1560,7 @@ abstract class CI_DB_driver {
 	 */
 	protected function _cache_init()
 	{
-		if (class_exists('CI_DB_Cache'))
+		if (class_exists('CI_DB_Cache', FALSE))
 		{
 			if (is_object($this->CACHE))
 			{
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index ac377d996..85a233b50 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -937,7 +937,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$this->qb_where[] = array('condition' => $like_statement, 'escape' => $escape);
 			if ($this->qb_caching === TRUE)
 			{
-				$this->qb_cache_where[] = $like_statement;
+				$this->qb_cache_where[] = array('condition' => $like_statement, 'escape' => $escape);
 				$this->qb_cache_exists[] = 'where';
 			}
 		}
@@ -2627,6 +2627,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		$this->_reset_run(array(
 			'qb_set'	=> array(),
 			'qb_from'	=> array(),
+			'qb_join'	=> array(),
 			'qb_where'	=> array(),
 			'qb_orderby'	=> array(),
 			'qb_keys'	=> array(),
diff --git a/system/database/drivers/mssql/mssql_result.php b/system/database/drivers/mssql/mssql_result.php
index ea3f8e4d1..b6e5f2b17 100644
--- a/system/database/drivers/mssql/mssql_result.php
+++ b/system/database/drivers/mssql/mssql_result.php
@@ -74,6 +74,7 @@ class CI_DB_mssql_result extends CI_DB_result {
 	public function list_fields()
 	{
 		$field_names = array();
+		mssql_field_seek($this->result_id, 0);
 		while ($field = mssql_fetch_field($this->result_id))
 		{
 			$field_names[] = $field->name;
diff --git a/system/database/drivers/mysql/mysql_result.php b/system/database/drivers/mysql/mysql_result.php
index 1ed2759b6..a2affcb58 100644
--- a/system/database/drivers/mysql/mysql_result.php
+++ b/system/database/drivers/mysql/mysql_result.php
@@ -89,6 +89,7 @@ class CI_DB_mysql_result extends CI_DB_result {
 	public function list_fields()
 	{
 		$field_names = array();
+		mysql_field_seek($this->result_id, 0);
 		while ($field = mysql_fetch_field($this->result_id))
 		{
 			$field_names[] = $field->name;
diff --git a/system/database/drivers/mysqli/mysqli_result.php b/system/database/drivers/mysqli/mysqli_result.php
index 4105f99f6..3fe05f9c5 100644
--- a/system/database/drivers/mysqli/mysqli_result.php
+++ b/system/database/drivers/mysqli/mysqli_result.php
@@ -74,6 +74,7 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	public function list_fields()
 	{
 		$field_names = array();
+		$this->result_id->field_seek(0);
 		while ($field = $this->result_id->fetch_field())
 		{
 			$field_names[] = $field->name;
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index 34adf0f86..fa89661b1 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -49,13 +49,6 @@ class CI_DB_pdo_driver extends CI_DB {
 	public $dbdriver = 'pdo';
 
 	/**
-	 * Transaction enabled flag
-	 *
-	 * @var	bool
-	 */
-	public $trans_enabled = FALSE;
-
-	/**
 	 * PDO Options
 	 *
 	 * @var	array
diff --git a/system/helpers/captcha_helper.php b/system/helpers/captcha_helper.php
index 83783324b..78e255a15 100644
--- a/system/helpers/captcha_helper.php
+++ b/system/helpers/captcha_helper.php
@@ -93,7 +93,7 @@ if ( ! function_exists('create_captcha'))
 		// Do we have a "word" yet?
 		// -----------------------------------
 
-		if ($word === '')
+		if (empty($word))
 		{
 			$pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
 			$word = '';
@@ -102,6 +102,10 @@ if ( ! function_exists('create_captcha'))
 				$word .= $pool[mt_rand(0, $mt_rand_max)];
 			}
 		}
+		elseif ( ! is_string($word))
+		{
+			$word = (string) $word;
+		}
 
 		// -----------------------------------
 		// Determine angle and position
diff --git a/system/helpers/download_helper.php b/system/helpers/download_helper.php
index d7691cb61..daf59f51b 100644
--- a/system/helpers/download_helper.php
+++ b/system/helpers/download_helper.php
@@ -58,7 +58,7 @@ if ( ! function_exists('force_download'))
 		}
 		elseif ($data === NULL)
 		{
-			if (@is_file($filename) && @file_exists($filename) && ($filesize = @filesize($filename)) !== FALSE)
+			if (@is_file($filename) && ($filesize = @filesize($filename)) !== FALSE)
 			{
 				$filepath = $filename;
 				$filename = explode('/', str_replace(DIRECTORY_SEPARATOR, '/', $filename));
diff --git a/system/helpers/form_helper.php b/system/helpers/form_helper.php
index f343b6c71..692909c79 100644
--- a/system/helpers/form_helper.php
+++ b/system/helpers/form_helper.php
@@ -228,13 +228,10 @@ if ( ! function_exists('form_upload'))
 	 */
 	function form_upload($data = '', $value = '', $extra = '')
 	{
-		if ( ! is_array($data))
-		{
-			$data = array('name' => $data);
-		}
-
+		$defaults = array('type' => 'file', 'name' => '');
+		is_array($data) OR $data = array('name' => $data);
 		$data['type'] = 'file';
-		return form_input($data, $value, $extra);
+		return '<input '._parse_form_attributes($data, $defaults).$extra." />\n";
 	}
 }
 
diff --git a/system/helpers/html_helper.php b/system/helpers/html_helper.php
index 2d474169b..80a27876f 100644
--- a/system/helpers/html_helper.php
+++ b/system/helpers/html_helper.php
@@ -238,26 +238,30 @@ if ( ! function_exists('doctype'))
 	 */
 	function doctype($type = 'xhtml1-strict')
 	{
-		global $_doctypes;
+		static $doctypes;
 
-		if ( ! is_array($_doctypes))
+		if ( ! is_array($doctypes))
 		{
-			if (defined('ENVIRONMENT') && is_file(APPPATH.'config/'.ENVIRONMENT.'/doctypes.php'))
+			if (file_exists(APPPATH.'config/doctypes.php'))
 			{
-				include(APPPATH.'config/'.ENVIRONMENT.'/doctypes.php');
+				include(APPPATH.'config/doctypes.php');
 			}
-			elseif (is_file(APPPATH.'config/doctypes.php'))
+
+			if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/doctypes.php'))
 			{
-				include(APPPATH.'config/doctypes.php');
+				include(APPPATH.'config/'.ENVIRONMENT.'/doctypes.php');
 			}
 
-			if ( ! is_array($_doctypes))
+			if (empty($_doctypes) OR ! is_array($_doctypes))
 			{
+				$doctypes = array();
 				return FALSE;
 			}
+
+			$doctypes = $_doctypes;
 		}
 
-		return isset($_doctypes[$type]) ? $_doctypes[$type] : FALSE;
+		return isset($doctypes[$type]) ? $doctypes[$type] : FALSE;
 	}
 }
 
diff --git a/system/helpers/smiley_helper.php b/system/helpers/smiley_helper.php
index 186b24ce9..d9a693493 100644
--- a/system/helpers/smiley_helper.php
+++ b/system/helpers/smiley_helper.php
@@ -213,16 +213,30 @@ if ( ! function_exists('_get_smiley_array'))
 	 */
 	function _get_smiley_array()
 	{
-		if (defined('ENVIRONMENT') && file_exists(APPPATH.'config/'.ENVIRONMENT.'/smileys.php'))
-		{
-			include(APPPATH.'config/'.ENVIRONMENT.'/smileys.php');
-		}
-		elseif (file_exists(APPPATH.'config/smileys.php'))
+		static $_smileys;
+
+		if ( ! is_array($smileys))
 		{
-			include(APPPATH.'config/smileys.php');
+			if (file_exists(APPPATH.'config/smileys.php'))
+			{
+				include(APPPATH.'config/smileys.php');
+			}
+
+			if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/smileys.php'))
+			{
+				include(APPPATH.'config/'.ENVIRONMENT.'/smileys.php');
+			}
+
+			if (empty($smileys) OR ! is_array($smileys))
+			{
+				$_smileys = array();
+				return FALSE;
+			}
+
+			$_smileys = $smileys;
 		}
 
-		return (isset($smileys) && is_array($smileys)) ? $smileys : FALSE;
+		return $_smileys;
 	}
 }
 
diff --git a/system/helpers/text_helper.php b/system/helpers/text_helper.php
index 1c7eeaf5f..54db14f94 100644
--- a/system/helpers/text_helper.php
+++ b/system/helpers/text_helper.php
@@ -358,31 +358,35 @@ if ( ! function_exists('convert_accented_characters'))
 	/**
 	 * Convert Accented Foreign Characters to ASCII
 	 *
-	 * @param	string	the text string
+	 * @param	string	$str	Input string
 	 * @return	string
 	 */
 	function convert_accented_characters($str)
 	{
-		global $foreign_characters;
+		static $_foreign_characters;
 
-		if ( ! isset($foreign_characters) OR ! is_array($foreign_characters))
+		if ( ! is_array($_foreign_characters))
 		{
-			if (defined('ENVIRONMENT') && is_file(APPPATH.'config/'.ENVIRONMENT.'/foreign_chars.php'))
+			if (file_exists(APPPATH.'config/foreign_chars.php'))
 			{
-				include(APPPATH.'config/'.ENVIRONMENT.'/foreign_chars.php');
+				include(APPPATH.'config/foreign_chars.php');
 			}
-			elseif (is_file(APPPATH.'config/foreign_chars.php'))
+
+			if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/foreign_chars.php'))
 			{
-				include(APPPATH.'config/foreign_chars.php');
+				include(APPPATH.'config/'.ENVIRONMENT.'/foreign_chars.php');
 			}
 
-			if ( ! isset($foreign_characters) OR ! is_array($foreign_characters))
+			if (empty($foreign_characters) OR ! is_array($foreign_characters))
 			{
+				$_foreign_characters = array();
 				return $str;
 			}
+
+			$_foreign_characters = $foreign_characters;
 		}
 
-		return preg_replace(array_keys($foreign_characters), array_values($foreign_characters), $str);
+		return preg_replace(array_keys($_foreign_characters), array_values($_foreign_characters), $str);
 	}
 }
 
diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 9a0153542..d6bf7e2c9 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -384,22 +384,23 @@ if ( ! function_exists('auto_link'))
 	function auto_link($str, $type = 'both', $popup = FALSE)
 	{
 		// Find and replace any URLs.
-		if ($type !== 'email' && preg_match_all('#\b(([\w-]+://?|www\.)[^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/)))#', $str, $matches, PREG_OFFSET_CAPTURE))
+		if ($type !== 'email' && preg_match_all('#(\w*://|www\.)[^\s()<>;]+\w#i', $str, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER))
 		{
 			// Set our target HTML if using popup links.
-			$target = ($popup) ? 'target="_blank"' : '';
+			$target = ($popup) ? ' target="_blank"' : '';
 
 			// We process the links in reverse order (last -> first) so that
 			// the returned string offsets from preg_match_all() are not
 			// moved as we add more HTML.
-			foreach (array_reverse($matches[0]) as $match)
+			foreach (array_reverse($matches) as $match)
 			{
-				// $match is an array generated by the PREG_OFFSET_CAPTURE flag.
-				// $match[0] is the matched string, $match[1] is the string offset.
-
-				$anchor = anchor($match[0], '', $target);
-
-				$str = substr_replace($str, $anchor, $match[1], strlen($match[0]));
+				// $match[0] is the matched string/link
+				// $match[1] is either a protocol prefix or 'www.'
+				//
+				// With PREG_OFFSET_CAPTURE, both of the above is an array,
+				// where the actual value is held in [0] and its offset at the [1] index.
+				$a = '<a href="'.(strpos($match[1][0], '/') ? '' : 'http://').$match[0][0].'"'.$target.'>'.$match[0][0].'</a>';
+				$str = substr_replace($str, $a, $match[0][1], strlen($match[0][0]));
 			}
 		}
 
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index 3fb007dd2..7c0277c25 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -37,6 +37,7 @@ $lang['form_validation_max_length']		= 'The {field} field cannot exceed {param}
 $lang['form_validation_exact_length']		= 'The {field} field must be exactly {param} characters in length.';
 $lang['form_validation_alpha']			= 'The {field} field may only contain alphabetical characters.';
 $lang['form_validation_alpha_numeric']		= 'The {field} field may only contain alpha-numeric characters.';
+$lang['form_validation_alpha_numeric_spaces']	= 'The {field} field may only contain alpha-numeric characters and spaces.';
 $lang['form_validation_alpha_dash']		= 'The {field} field may only contain alpha-numeric characters, underscores, and dashes.';
 $lang['form_validation_numeric']		= 'The {field} field must contain only numbers.';
 $lang['form_validation_is_numeric']		= 'The {field} field must contain only numeric characters.';
diff --git a/system/language/english/profiler_lang.php b/system/language/english/profiler_lang.php
index dfe034e79..0ed5f4cb0 100644
--- a/system/language/english/profiler_lang.php
+++ b/system/language/english/profiler_lang.php
@@ -46,6 +46,7 @@ $lang['profiler_no_memory']		= 'Memory Usage Unavailable';
 $lang['profiler_no_profiles']	= 'No Profile data - all Profiler sections have been disabled.';
 $lang['profiler_section_hide']	= 'Hide';
 $lang['profiler_section_show']	= 'Show';
+$lang['profiler_seconds']		= 'seconds';
 
 /* End of file profiler_lang.php */
 /* Location: ./system/language/english/profiler_lang.php */
\ No newline at end of file
diff --git a/system/libraries/Cache/drivers/Cache_memcached.php b/system/libraries/Cache/drivers/Cache_memcached.php
index 8096b2650..246a7a264 100644
--- a/system/libraries/Cache/drivers/Cache_memcached.php
+++ b/system/libraries/Cache/drivers/Cache_memcached.php
@@ -182,11 +182,11 @@ class CI_Cache_memcached extends CI_Driver {
 			}
 		}
 
-		if (class_exists('Memcached'))
+		if (class_exists('Memcached', FALSE))
 		{
 			$this->_memcached = new Memcached();
 		}
-		elseif (class_exists('Memcache'))
+		elseif (class_exists('Memcache', FALSE))
 		{
 			$this->_memcached = new Memcache();
 		}
diff --git a/system/libraries/Cart.php b/system/libraries/Cart.php
index 8734d7774..b7b0697fb 100644
--- a/system/libraries/Cart.php
+++ b/system/libraries/Cart.php
@@ -95,7 +95,7 @@ class CI_Cart {
 		$config = is_array($params) ? $params : array();
 
 		// Load the Sessions class
-		$this->CI->load->library('session', $config);
+		$this->CI->load->driver('session', $config);
 
 		// Grab the shopping cart array from the session table
 		$this->_cart_contents = $this->CI->session->userdata('cart_contents');
@@ -365,7 +365,7 @@ class CI_Cart {
 	 */
 	protected function _save_cart()
 	{
-		// Lets add up the individual prices and set the cart sub-total
+		// Let's add up the individual prices and set the cart sub-total
 		$this->_cart_contents['total_items'] = $this->_cart_contents['cart_total'] = 0;
 		foreach ($this->_cart_contents as $key => $val)
 		{
diff --git a/system/libraries/Driver.php b/system/libraries/Driver.php
index bb7318991..ba15f81df 100644
--- a/system/libraries/Driver.php
+++ b/system/libraries/Driver.php
@@ -80,8 +80,7 @@ class CI_Driver_Library {
 	public function load_driver($child)
 	{
 		// Get CodeIgniter instance and subclass prefix
-		$CI = get_instance();
-		$prefix = (string) $CI->config->item('subclass_prefix');
+		$prefix = config_item('subclass_prefix');
 
 		if ( ! isset($this->lib_name))
 		{
@@ -102,11 +101,12 @@ class CI_Driver_Library {
 		}
 
 		// Get package paths and filename case variations to search
+		$CI = get_instance();
 		$paths = $CI->load->get_package_paths(TRUE);
 
 		// Is there an extension?
 		$class_name = $prefix.$child_name;
-		$found = class_exists($class_name);
+		$found = class_exists($class_name, FALSE);
 		if ( ! $found)
 		{
 			// Check for subclass file
@@ -126,8 +126,8 @@ class CI_Driver_Library {
 					}
 
 					// Include both sources and mark found
-					include($basepath);
-					include($file);
+					include_once($basepath);
+					include_once($file);
 					$found = TRUE;
 					break;
 				}
@@ -139,8 +139,7 @@ class CI_Driver_Library {
 		{
 			// Use standard class name
 			$class_name = 'CI_'.$child_name;
-			$found = class_exists($class_name);
-			if ( ! $found)
+			if ( ! class_exists($class_name, FALSE))
 			{
 				// Check package paths
 				foreach ($paths as $path)
@@ -150,7 +149,7 @@ class CI_Driver_Library {
 					if (file_exists($file))
 					{
 						// Include source
-						include($file);
+						include_once($file);
 						break;
 					}
 				}
@@ -158,9 +157,9 @@ class CI_Driver_Library {
 		}
 
 		// Did we finally find the class?
-		if ( ! class_exists($class_name))
+		if ( ! class_exists($class_name, FALSE))
 		{
-			if (class_exists($child_name))
+			if (class_exists($child_name, FALSE))
 			{
 				$class_name = $child_name;
 			}
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 997757b0a..daa38484b 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -96,6 +96,13 @@ class CI_Email {
 	public $smtp_timeout	= 5;
 
 	/**
+	 * SMTP persistent connection
+	 *
+	 * @var	bool
+	 */
+	public $smtp_keepalive	= FALSE;
+
+	/**
 	 * SMTP Encryption
 	 *
 	 * @var	string	NULL, 'tls' or 'ssl'
@@ -403,6 +410,21 @@ class CI_Email {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Destructor - Releases Resources
+	 *
+	 * @return	void
+	 */
+	public function __destruct()
+	{
+		if (is_resource($this->_smtp_connect))
+		{
+			$this->_send_command('quit');
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Initialize preferences
 	 *
 	 * @param	array
@@ -1183,8 +1205,11 @@ class CI_Email {
 	{
 		if ($this->protocol === 'mail')
 		{
-			$this->_subject = $this->_headers['Subject'];
-			unset($this->_headers['Subject']);
+			if (isset($this->_headers['Subject']))
+			{
+				$this->_subject = $this->_headers['Subject'];
+				unset($this->_headers['Subject']);
+			}
 		}
 
 		reset($this->_headers);
@@ -1824,7 +1849,15 @@ class CI_Email {
 			return FALSE;
 		}
 
-		$this->_send_command('quit');
+		if ($this->smtp_keepalive)
+		{
+			$this->_send_command('reset');
+		}
+		else
+		{
+			$this->_send_command('quit');
+		}
+
 		return TRUE;
 	}
 
@@ -1837,6 +1870,11 @@ class CI_Email {
 	 */
 	protected function _smtp_connect()
 	{
+		if (is_resource($this->_smtp_connect))
+		{
+			return TRUE;
+		}
+
 		$ssl = ($this->smtp_crypto === 'ssl') ? 'ssl://' : NULL;
 
 		$this->_smtp_connect = fsockopen($ssl.$this->smtp_host,
@@ -1851,6 +1889,7 @@ class CI_Email {
 			return FALSE;
 		}
 
+		stream_set_timeout($this->_smtp_connect, $this->smtp_timeout);
 		$this->_set_error_message($this->_get_smtp_data());
 
 		if ($this->smtp_crypto === 'tls')
@@ -1924,6 +1963,11 @@ class CI_Email {
 						$this->_send_data('DATA');
 						$resp = 354;
 			break;
+			case 'reset':
+
+						$this->_send_data('RSET');
+						$resp = 250;
+			break;
 			case 'quit'	:
 
 						$this->_send_data('QUIT');
@@ -1973,6 +2017,11 @@ class CI_Email {
 
 		$reply = $this->_get_smtp_data();
 
+		if (strpos($reply, '503') !== 0)	// Already authenticated
+		{
+			return TRUE;
+		}
+
 		if (strpos($reply, '334') !== 0)
 		{
 			$this->_set_error_message('lang:email_failed_smtp_login', $reply);
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index bbd0b523e..172e799f6 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -356,7 +356,7 @@ class CI_Form_validation {
 	 */
 	public function error_string($prefix = '', $suffix = '')
 	{
-		// No errrors, validation passes!
+		// No errors, validation passes!
 		if (count($this->_error_array) === 0)
 		{
 			return '';
@@ -517,7 +517,7 @@ class CI_Form_validation {
 				{
 					if (isset($_POST[$row['field']]))
 					{
-						$_POST[$row['field']] = $this->prep_for_form($row['postdata']);
+						$_POST[$row['field']] = $row['postdata'];
 					}
 				}
 				else
@@ -543,14 +543,14 @@ class CI_Form_validation {
 						$array = array();
 						foreach ($row['postdata'] as $k => $v)
 						{
-							$array[$k] = $this->prep_for_form($v);
+							$array[$k] = $v;
 						}
 
 						$post_ref = $array;
 					}
 					else
 					{
-						$post_ref = $this->prep_for_form($row['postdata']);
+						$post_ref = $row['postdata'];
 					}
 				}
 			}
@@ -1232,6 +1232,19 @@ class CI_Form_validation {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Alpha-numeric w/ spaces
+	 *
+	 * @param	string
+	 * @return	bool
+	 */
+	public function alpha_numeric_spaces($str)
+	{
+		return (bool) preg_match('/^[A-Z0-9 ]+$/i', $str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Alpha-numeric with underscores and dashes
 	 *
 	 * @param	string
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index 6d5493696..0cec43fc4 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -810,7 +810,7 @@ class CI_Image_lib {
 		imagedestroy($dst_img);
 		imagedestroy($src_img);
 
-		// Set the file to 777
+		// Set the file to 666
 		@chmod($this->full_dst_path, FILE_WRITE_MODE);
 
 		return TRUE;
diff --git a/system/libraries/Javascript.php b/system/libraries/Javascript.php
index 7f1d85511..773a58384 100644
--- a/system/libraries/Javascript.php
+++ b/system/libraries/Javascript.php
@@ -69,7 +69,7 @@ class CI_Javascript {
 		$this->CI =& get_instance();
 
 		// load the requested js library
-		$this->CI->load->library('javascript/'.$js_library_driver, array('autoload' => $autoload));
+		$this->CI->load->library('Javascript/'.$js_library_driver, array('autoload' => $autoload));
 		// make js to refer to current library
 		$this->js =& $this->CI->$js_library_driver;
 
diff --git a/system/libraries/javascript/Jquery.php b/system/libraries/Javascript/Jquery.php
index b6e0434b2..b6e0434b2 100644
--- a/system/libraries/javascript/Jquery.php
+++ b/system/libraries/Javascript/Jquery.php
diff --git a/system/libraries/javascript/index.html b/system/libraries/Javascript/index.html
index c942a79ce..c942a79ce 100644
--- a/system/libraries/javascript/index.html
+++ b/system/libraries/Javascript/index.html
diff --git a/system/libraries/Migration.php b/system/libraries/Migration.php
index fd915c382..cc6fe48f0 100644
--- a/system/libraries/Migration.php
+++ b/system/libraries/Migration.php
@@ -104,8 +104,8 @@ class CI_Migration {
 	 */
 	public function __construct($config = array())
 	{
-		# Only run this constructor on main library load
-		if (get_parent_class($this) !== FALSE)
+		// Only run this constructor on main library load
+		if ( ! in_array(get_class($this), array('CI_Migration', config_item('subclass_prefix').'Migration'), TRUE))
 		{
 			return;
 		}
@@ -228,7 +228,7 @@ class CI_Migration {
 			$class = 'Migration_'.ucfirst(strtolower($this->_get_migration_name(basename($file, '.php'))));
 
 			// Validate the migration file structure
-			if ( ! class_exists($class))
+			if ( ! class_exists($class, FALSE))
 			{
 				$this->_error_string = sprintf($this->lang->line('migration_class_doesnt_exist'), $class);
 				return FALSE;
diff --git a/system/libraries/Pagination.php b/system/libraries/Pagination.php
index d139980d8..10fb29dbd 100644
--- a/system/libraries/Pagination.php
+++ b/system/libraries/Pagination.php
@@ -133,7 +133,7 @@ class CI_Pagination {
 	 *
 	 * @var	int
 	 */
-	protected $uri_segment		= 3;
+	protected $uri_segment		= 0;
 
 	/**
 	 * Full tag open
@@ -318,11 +318,9 @@ class CI_Pagination {
 	 */
 	public function initialize($params = array())
 	{
-		$attributes = array();
-
 		if (isset($params['attributes']) && is_array($params['attributes']))
 		{
-			$attributes = $params['attributes'];
+			$this->_parse_attributes($params['attributes']);
 			unset($params['attributes']);
 		}
 
@@ -334,8 +332,6 @@ class CI_Pagination {
 			unset($params['anchor_class']);
 		}
 
-		$this->_parse_attributes($attributes);
-
 		if (count($params) > 0)
 		{
 			foreach ($params as $key => $val)
@@ -372,45 +368,119 @@ class CI_Pagination {
 			return '';
 		}
 
-		// Set the base page index for starting page number
-		$base_page = ($this->use_page_numbers) ? 1 : 0;
+		// Check the user defined number of links.
+		$this->num_links = (int) $this->num_links;
+
+		if ($this->num_links < 1)
+		{
+			show_error('Your number of links must be a positive number.');
+		}
 
-		// Determine the current page number.
 		$CI =& get_instance();
 
-		// See if we are using a prefix or suffix on links
-		if ($this->prefix !== '' OR $this->suffix !== '')
+		// Keep any existing query string items.
+		// Note: Has nothing to do with any other query string option.
+		if ($this->reuse_query_string === TRUE)
 		{
-			$this->cur_page = (int) str_replace(array($this->prefix, $this->suffix), '', $CI->uri->rsegment($this->uri_segment));
+			$get = $CI->input->get();
+
+			// Unset the controll, method, old-school routing options
+			unset($get['c'], $get['m'], $get[$this->query_string_segment]);
+		}
+		else
+		{
+			$get = array();
 		}
 
+		// Put together our base and first URLs.
+		$this->base_url = trim($this->base_url);
+
+		$query_string = '';
+		$query_string_sep = (strpos($this->base_url, '?') === FALSE) ? '?' : '&amp;';
+
+		// Are we using query strings?
 		if ($CI->config->item('enable_query_strings') === TRUE OR $this->page_query_string === TRUE)
 		{
-			if ($CI->input->get($this->query_string_segment) != $base_page)
+			// If a custom first_url hasn't been specified, we'll create one from
+			// the base_url, but without the page item.
+			if ($this->first_url === '')
 			{
-				$this->cur_page = (int) $CI->input->get($this->query_string_segment);
+				$this->first_url = $this->base_url;
+
+				// If we saved any GET items earlier, make sure they're appended.
+				if ( ! empty($get))
+				{
+					$this->first_url .= $query_string_sep.http_build_query($get);
+				}
 			}
+
+			// Add the page segment to the end of the query string, where the
+			// page number will be appended.
+			$this->base_url .= $query_string_sep.http_build_query(array_merge($get, array($this->query_string_segment => '')));
 		}
-		elseif ( ! $this->cur_page && $CI->uri->segment($this->uri_segment) !== $base_page)
+		else
 		{
-			$this->cur_page = (int) $CI->uri->rsegment($this->uri_segment);
+			// Standard segment mode.
+			// Generate our saved query string to append later after the page number.
+			if ( ! empty($get))
+			{
+				$query_string = $query_string_sep.http_build_query($get);
+				$this->suffix .= $query_string;
+			}
+
+			// Does the base_url have the query string in it?
+			// If we're supposed to save it, remove it so we can append it later.
+			if ($this->reuse_query_string === TRUE && ($base_query_pos = strpos($this->base_url, '?')) !== FALSE)
+			{
+				$this->base_url = substr($this->base_url, 0, $base_query_pos);
+			}
+
+			if ($this->first_url === '')
+			{
+				$this->first_url = $this->base_url.$query_string;
+			}
+
+			$this->base_url = rtrim($this->base_url, '/').'/';
 		}
 
-		// Set current page to 1 if it's not valid or if using page numbers instead of offset
-		if ( ! is_numeric($this->cur_page) OR ($this->use_page_numbers && $this->cur_page === 0))
+		// Determine the current page number.
+		$base_page = ($this->use_page_numbers) ? 1 : 0;
+
+		// Are we using query strings?
+		if ($CI->config->item('enable_query_strings') === TRUE OR $this->page_query_string === TRUE)
 		{
-			$this->cur_page = $base_page;
+			$this->cur_page = $CI->input->get($this->query_string_segment);
 		}
+		else
+		{
+			// Default to the last segment number if one hasn't been defined.
+			if ($this->uri_segment === 0)
+			{
+				$this->uri_segment = count($CI->uri->segment_array());
+			}
 
-		$this->num_links = (int) $this->num_links;
+			$this->cur_page = $CI->uri->segment($this->uri_segment);
 
-		if ($this->num_links < 1)
+			// Remove any specified prefix/suffix from the segment.
+			if ($this->prefix !== '' OR $this->suffix !== '')
+			{
+				$this->cur_page = str_replace(array($this->prefix, $this->suffix), '', $this->cur_page);
+			}
+		}
+
+		// If something isn't quite right, back to the default base page.
+		if ( ! ctype_digit($this->cur_page) OR ($this->use_page_numbers && (int) $this->cur_page === 0))
 		{
-			show_error('Your number of links must be a positive number.');
+			$this->cur_page = $base_page;
+		}
+		else
+		{
+			// Make sure we're using integers for comparisons later.
+			$this->cur_page = (int) $this->cur_page;
 		}
 
 		// Is the page number beyond the result range?
-		// If so we show the last page
+		// If so, we show the last page.
 		if ($this->use_page_numbers)
 		{
 			if ($this->cur_page > $num_pages)
@@ -425,80 +495,47 @@ class CI_Pagination {
 
 		$uri_page_number = $this->cur_page;
 
+		// If we're using offset instead of page numbers, convert it
+		// to a page number, so we can generate the surrounding number links.
 		if ( ! $this->use_page_numbers)
 		{
 			$this->cur_page = (int) floor(($this->cur_page/$this->per_page) + 1);
 		}
 
 		// Calculate the start and end numbers. These determine
-		// which number to start and end the digit links with
+		// which number to start and end the digit links with.
 		$start	= (($this->cur_page - $this->num_links) > 0) ? $this->cur_page - ($this->num_links - 1) : 1;
 		$end	= (($this->cur_page + $this->num_links) < $num_pages) ? $this->cur_page + $this->num_links : $num_pages;
 
-		// Is pagination being used over GET or POST? If get, add a per_page query
-		// 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)
-		{
-			$segment = (strpos($this->base_url, '?')) ? '&amp;' : '?';
-			$this->base_url = rtrim($this->base_url).$segment.$this->query_string_segment.'=';
-		}
-		else
-		{
-			$this->base_url = rtrim($this->base_url, '/') .'/';
-		}
-
 		// And here we go...
 		$output = '';
-		$query_string = '';
-
-		// Add anything in the query string back to the links
-		// Note: Nothing to do with query_string_segment or any other query string options
-		if ($this->reuse_query_string === TRUE)
-		{
-			$get = $CI->input->get();
-
-			// Unset the controll, method, old-school routing options
-			unset($get['c'], $get['m'], $get[$this->query_string_segment]);
 
-			if ( ! empty($get))
-			{
-				// Put everything else onto the end
-				$query_string = (strpos($this->base_url, '?') !== FALSE ? '&amp;' : '?')
-						.http_build_query($get, '', '&amp;');
-
-				// Add this after the suffix to put it into more links easily
-				$this->suffix .= $query_string;
-			}
-		}
-
-		// Render the "First" link
+		// Render the "First" link.
 		if ($this->first_link !== FALSE && $this->cur_page > ($this->num_links + 1))
 		{
-			$first_url = ($this->first_url === '') ? $this->base_url : $this->first_url;
-
-			// Take the general parameters, and squeeze this pagination-page attr in there for JS fw's
+			// Take the general parameters, and squeeze this pagination-page attr in for JS frameworks.
 			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, 1);
 
-			$output .= $this->first_tag_open.'<a href="'.$first_url.'"'.$attributes.$this->_attr_rel('start').'>'
+			$output .= $this->first_tag_open.'<a href="'.$this->first_url.'"'.$attributes.$this->_attr_rel('start').'>'
 				.$this->first_link.'</a>'.$this->first_tag_close;
 		}
 
-		// Render the "previous" link
+		// Render the "Previous" link.
 		if ($this->prev_link !== FALSE && $this->cur_page !== 1)
 		{
 			$i = ($this->use_page_numbers) ? $uri_page_number - 1 : $uri_page_number - $this->per_page;
 
-			// Take the general parameters, and squeeze this pagination-page attr in there for JS fw's
 			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
 
-			if ($i === $base_page && $this->first_url !== '')
+			if ($i === $base_page)
 			{
-				$output .= $this->prev_tag_open.'<a href="'.$this->first_url.$query_string.'"'.$attributes.$this->_attr_rel('prev').'>'
+				// First page
+				$output .= $this->prev_tag_open.'<a href="'.$this->first_url.'"'.$attributes.$this->_attr_rel('prev').'>'
 					.$this->prev_link.'</a>'.$this->prev_tag_close;
 			}
 			else
 			{
-				$append = ($i === $base_page) ? $query_string : $this->prefix.$i.$this->suffix;
+				$append = $this->prefix.$i.$this->suffix;
 				$output .= $this->prev_tag_open.'<a href="'.$this->base_url.$append.'"'.$attributes.$this->_attr_rel('prev').'>'
 					.$this->prev_link.'</a>'.$this->prev_tag_close;
 			}
@@ -513,29 +550,26 @@ class CI_Pagination {
 			{
 				$i = ($this->use_page_numbers) ? $loop : ($loop * $this->per_page) - $this->per_page;
 
-				// Take the general parameters, and squeeze this pagination-page attr in there for JS fw's
 				$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
 
 				if ($i >= $base_page)
 				{
 					if ($this->cur_page === $loop)
 					{
-						$output .= $this->cur_tag_open.$loop.$this->cur_tag_close; // Current page
+						// Current page
+						$output .= $this->cur_tag_open.$loop.$this->cur_tag_close;
+					}
+					elseif ($i === $base_page)
+					{
+						// First page
+						$output .= $this->num_tag_open.'<a href="'.$this->first_url.'"'.$attributes.$this->_attr_rel('start').'>'
+							.$loop.'</a>'.$this->num_tag_close;
 					}
 					else
 					{
-						$n = ($i === $base_page) ? '' : $i;
-						if ($n === '' && ! empty($this->first_url))
-						{
-							$output .= $this->num_tag_open.'<a href="'.$this->first_url.$query_string.'"'.$attributes.$this->_attr_rel('start').'>'
-								.$loop.'</a>'.$this->num_tag_close;
-						}
-						else
-						{
-							$append = ($n === '') ? $query_string : $this->prefix.$n.$this->suffix;
-							$output .= $this->num_tag_open.'<a href="'.$this->base_url.$append.'"'.$attributes.$this->_attr_rel('start').'>'
-								.$loop.'</a>'.$this->num_tag_close;
-						}
+						$append = $this->prefix.$i.$this->suffix;
+						$output .= $this->num_tag_open.'<a href="'.$this->base_url.$append.'"'.$attributes.$this->_attr_rel('start').'>'
+							.$loop.'</a>'.$this->num_tag_close;
 					}
 				}
 			}
@@ -546,7 +580,6 @@ class CI_Pagination {
 		{
 			$i = ($this->use_page_numbers) ? $this->cur_page + 1 : $this->cur_page * $this->per_page;
 
-			// Take the general parameters, and squeeze this pagination-page attr in there for JS fw's
 			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
 
 			$output .= $this->next_tag_open.'<a href="'.$this->base_url.$this->prefix.$i.$this->suffix.'"'.$attributes
@@ -558,7 +591,6 @@ class CI_Pagination {
 		{
 			$i = ($this->use_page_numbers) ? $num_pages : ($num_pages * $this->per_page) - $this->per_page;
 
-			// Take the general parameters, and squeeze this pagination-page attr in there for JS fw's
 			$attributes = sprintf('%s %s="%d"', $this->_attributes, $this->data_page_attr, (int) $i);
 
 			$output .= $this->last_tag_open.'<a href="'.$this->base_url.$this->prefix.$i.$this->suffix.'"'.$attributes.'>'
diff --git a/system/libraries/Profiler.php b/system/libraries/Profiler.php
index e93239901..470688fdc 100644
--- a/system/libraries/Profiler.php
+++ b/system/libraries/Profiler.php
@@ -238,6 +238,7 @@ class CI_Profiler {
 		foreach ($dbs as $name => $db)
 		{
 			$hide_queries = (count($db->queries) > $this->_query_toggle_count) ? ' display:none' : '';
+			$total_time = number_format(array_sum($db->query_times), 4).' '.$this->CI->lang->line('profiler_seconds');
 
 			$show_hide_js = '(<span style="cursor: pointer;" onclick="var s=document.getElementById(\'ci_profiler_queries_db_'.$count.'\').style;s.display=s.display==\'none\'?\'\':\'none\';this.innerHTML=this.innerHTML==\''.$this->CI->lang->line('profiler_section_hide').'\'?\''.$this->CI->lang->line('profiler_section_show').'\':\''.$this->CI->lang->line('profiler_section_hide').'\';">'.$this->CI->lang->line('profiler_section_hide').'</span>)';
 
@@ -250,7 +251,7 @@ class CI_Profiler {
 				."\n"
 				.'<legend style="color:#0000FF;">&nbsp;&nbsp;'.$this->CI->lang->line('profiler_database')
 				.':&nbsp; '.$db->database.' ('.$name.')&nbsp;&nbsp;&nbsp;'.$this->CI->lang->line('profiler_queries')
-				.': '.count($db->queries).'&nbsp;&nbsp;'.$show_hide_js."</legend>\n\n\n"
+				.': '.count($db->queries).' ('.$total_time.')&nbsp;&nbsp;'.$show_hide_js."</legend>\n\n\n"
 				.'<table style="width:100%;'.$hide_queries.'" id="ci_profiler_queries_db_'.$count."\">\n";
 
 			if (count($db->queries) === 0)
diff --git a/system/libraries/Session/drivers/Session_cookie.php b/system/libraries/Session/drivers/Session_cookie.php
index 474641642..057e5a1d1 100644
--- a/system/libraries/Session/drivers/Session_cookie.php
+++ b/system/libraries/Session/drivers/Session_cookie.php
@@ -602,6 +602,9 @@ class CI_Session_cookie extends CI_Session_driver {
 				$set['user_data'] = $this->_serialize($userdata);
 			}
 
+			// Reset query builder values.
+			$this->CI->db->reset_query();
+
 			// Run the update query
 			// Any time we change the session id, it gets updated immediately,
 			// so our where clause below is always safe
@@ -805,7 +808,7 @@ class CI_Session_cookie extends CI_Session_driver {
 	{
 		if (is_string($val))
 		{
-	 		$val= str_replace('{{slash}}', '\\', $val);
+	 		$val = str_replace('{{slash}}', '\\', $val);
 		}
 	}
 
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index 96bb17edc..1c14f99ed 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -430,7 +430,7 @@ class CI_Upload {
 			}
 			else
 			{
-				// An extension was provided, lets have it!
+				// An extension was provided, let's have it!
 				$this->file_ext	= $this->get_extension($this->_file_name_override);
 			}
 
@@ -463,7 +463,8 @@ class CI_Upload {
 		}
 
 		// Sanitize the file name for security
-		$this->file_name = $this->clean_file_name($this->file_name);
+		$CI =& get_instance();
+		$this->file_name = $CI->security->sanitize_filename($this->file_name);
 
 		// Truncate the file name if it's too long
 		if ($this->max_filename > 0)
@@ -971,46 +972,6 @@ class CI_Upload {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Clean the file name for security
-	 *
-	 * @param	string	$filename
-	 * @return	string
-	 */
-	public function clean_file_name($filename)
-	{
-		$bad = array(
-				'<!--', '-->',
-				"'", '"',
-				'<', '>',
-				'&', '$',
-				'=',
-				';',
-				'?',
-				'/',
-				'!',
-				'#',
-				'%20',
-				'%22',
-				'%3c',		// <
-				'%253c',	// <
-				'%3e',		// >
-				'%0e',		// >
-				'%28',		// (
-				'%29',		// )
-				'%2528',	// (
-				'%26',		// &
-				'%24',		// $
-				'%3f',		// ?
-				'%3b',		// ;
-				'%3d'		// =
-			);
-
-		return stripslashes(str_replace($bad, '', $filename));
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Limit the File Name Length
 	 *
 	 * @param	string	$filename
@@ -1089,7 +1050,7 @@ class CI_Upload {
 			// <a, <body, <head, <html, <img, <plaintext, <pre, <script, <table, <title
 			// title is basically just in SVG, but we filter it anyhow
 
-			// if its an image or no "triggers" detected in the first 256 bytes - we're good
+			// if it's an image or no "triggers" detected in the first 256 bytes - we're good
 			return ! preg_match('/<(a|body|head|html|img|plaintext|pre|script|table|title)[\s>]/i', $opening_bytes);
 		}
 
@@ -1251,7 +1212,7 @@ class CI_Upload {
 		 * Notes:
 		 *	- the DIRECTORY_SEPARATOR comparison ensures that we're not on a Windows system
 		 *	- many system admins would disable the exec(), shell_exec(), popen() and similar functions
-		 *	  due to security concerns, hence the function_exists() checks
+		 *	  due to security concerns, hence the function_usable() checks
 		 */
 		if (DIRECTORY_SEPARATOR !== '\\')
 		{
@@ -1262,7 +1223,7 @@ class CI_Upload {
 			if (function_usable('exec'))
 			{
 				/* This might look confusing, as $mime is being populated with all of the output when set in the second parameter.
-				 * However, we only neeed the last line, which is the actual return value of exec(), and as such - it overwrites
+				 * However, we only need the last line, which is the actual return value of exec(), and as such - it overwrites
 				 * anything that could already be set for $mime previously. This effectively makes the second parameter a dummy
 				 * value, which is only put to allow us to get the return status code.
 				 */
diff --git a/system/libraries/User_agent.php b/system/libraries/User_agent.php
index 1f4b2fa52..2f6f81909 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -175,15 +175,18 @@ class CI_User_agent {
 	 */
 	protected function _load_agent_file()
 	{
-		if (defined('ENVIRONMENT') && is_file(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php'))
+		if (($found = file_exists(APPPATH.'config/user_agents.php')))
 		{
-			include(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php');
+			include(APPPATH.'config/user_agents.php');
 		}
-		elseif (is_file(APPPATH.'config/user_agents.php'))
+
+		if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php'))
 		{
-			include(APPPATH.'config/user_agents.php');
+			include(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php');
+			$found = TRUE;
 		}
-		else
+
+		if ($found !== TRUE)
 		{
 			return FALSE;
 		}
diff --git a/system/libraries/Xmlrpcs.php b/system/libraries/Xmlrpcs.php
index 465a1967b..2d2e7f13b 100644
--- a/system/libraries/Xmlrpcs.php
+++ b/system/libraries/Xmlrpcs.php
@@ -31,7 +31,7 @@ if ( ! function_exists('xml_parser_create'))
 	show_error('Your PHP installation does not support XML');
 }
 
-if ( ! class_exists('CI_Xmlrpc'))
+if ( ! class_exists('CI_Xmlrpc', FALSE))
 {
 	show_error('You must load the Xmlrpc class before loading the Xmlrpcs class in order to create a server.');
 }