Merge branch 'refs/heads/develop' into feature/form_error_msgs

Conflicts:
	system/language/english/form_validation_lang.php
	user_guide_src/source/libraries/form_validation.rst

Signed-off-by: Eric Roberts <eric@cryode.com>

17 files changed, 2537 insertions, 1565 deletions

diff --git a/system/core/Benchmark.php b/system/core/Benchmark.php
index f6b634deb..e80ee54dd 100755..100644
--- a/system/core/Benchmark.php
+++ b/system/core/Benchmark.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,14 +24,13 @@
  * @since		Version 1.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
- * CodeIgniter Benchmark Class
+ * Benchmark Class
  *
  * This class enables you to mark points and calculate the time difference
- * between them.  Memory consumption can also be displayed.
+ * between them. Memory consumption can also be displayed.
  *
  * @package		CodeIgniter
  * @subpackage	Libraries
@@ -42,31 +41,31 @@
 class CI_Benchmark {
 
 	/**
-	 * List of all benchmark markers and when they were added
+	 * List of all benchmark markers
 	 *
-	 * @var array
+	 * @var	array
 	 */
 	public $marker = array();
 
-	// --------------------------------------------------------------------
-
 	/**
 	 * Set a benchmark marker
 	 *
 	 * Multiple calls to this function can be made so that several
-	 * execution points can be timed
+	 * execution points can be timed.
 	 *
-	 * @param	string	$name	name of the marker
+	 * @param	string	$name	Marker name
 	 * @return	void
 	 */
 	public function mark($name)
 	{
-		$this->marker[$name] = microtime();
+		$this->marker[$name] = microtime(TRUE);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
+	 * Elapsed time
+	 *
 	 * Calculates the time difference between two marked points.
 	 *
 	 * If the first parameter is empty this function instead returns the
@@ -74,14 +73,17 @@ class CI_Benchmark {
 	 * execution time to be shown in a template. The output class will
 	 * swap the real value for this variable.
 	 *
-	 * @param	string	a particular marked point
-	 * @param	string	a particular marked point
-	 * @param	integer	the number of decimal places
-	 * @return	mixed
+	 * @param	string	$point1		A particular marked point
+	 * @param	string	$point2		A particular marked point
+	 * @param	int	$decimals	Number of decimal places
+	 *
+	 * @return	string	Calculated elapsed time on success,
+	 *			an '{elapsed_string}' if $point1 is empty
+	 *			or an empty string if $point1 is not found.
 	 */
 	public function elapsed_time($point1 = '', $point2 = '', $decimals = 4)
 	{
-		if ($point1 == '')
+		if ($point1 === '')
 		{
 			return '{elapsed_time}';
 		}
@@ -93,13 +95,10 @@ class CI_Benchmark {
 
 		if ( ! isset($this->marker[$point2]))
 		{
-			$this->marker[$point2] = microtime();
+			$this->marker[$point2] = microtime(TRUE);
 		}
 
-		list($sm, $ss) = explode(' ', $this->marker[$point1]);
-		list($em, $es) = explode(' ', $this->marker[$point2]);
-
-		return number_format(($em + $es) - ($sm + $ss), $decimals);
+		return number_format($this->marker[$point2] - $this->marker[$point1], $decimals);
 	}
 
 	// --------------------------------------------------------------------
@@ -107,12 +106,13 @@ class CI_Benchmark {
 	/**
 	 * Memory Usage
 	 *
-	 * This function returns the {memory_usage} pseudo-variable.
+	 * Simply returns the {memory_usage} marker.
+	 *
 	 * This permits it to be put it anywhere in a template
 	 * without the memory being calculated until the end.
 	 * The output class will swap the real value for this variable.
 	 *
-	 * @return	string
+	 * @return	string	'{memory_usage}'
 	 */
 	public function memory_usage()
 	{
@@ -122,4 +122,4 @@ class CI_Benchmark {
 }
 
 /* End of file Benchmark.php */
-/* Location: ./system/core/Benchmark.php */
+/* Location: ./system/core/Benchmark.php */
\ No newline at end of file
diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index 4885f310c..89081b572 100755..100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,8 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * System Initialization File
@@ -33,7 +32,7 @@
  * Loads the base classes and executes the request.
  *
  * @package		CodeIgniter
- * @subpackage	codeigniter
+ * @subpackage	CodeIgniter
  * @category	Front-controller
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/
@@ -42,7 +41,7 @@
 /**
  * CodeIgniter Version
  *
- * @var string
+ * @var	string
  *
  */
 	define('CI_VERSION', '3.0-dev');
@@ -52,7 +51,7 @@
  *  Load the global functions
  * ------------------------------------------------------
  */
-	require(BASEPATH.'core/Common.php');
+	require_once(BASEPATH.'core/Common.php');
 
 /*
  * ------------------------------------------------------
@@ -75,9 +74,9 @@
  */
 	set_error_handler('_exception_handler');
 
-	if ( ! is_php('5.3'))
+	if ( ! is_php('5.4'))
 	{
-		@set_magic_quotes_runtime(0); // Kill magic quotes
+		@ini_set('magic_quotes_runtime', 0); // Kill magic quotes
 	}
 
 /*
@@ -96,24 +95,13 @@
  * Note: Since the config file data is cached it doesn't
  * hurt to load it here.
  */
-	if (isset($assign_to_config['subclass_prefix']) && $assign_to_config['subclass_prefix'] != '')
+	if ( ! empty($assign_to_config['subclass_prefix']))
 	{
 		get_config(array('subclass_prefix' => $assign_to_config['subclass_prefix']));
 	}
 
 /*
  * ------------------------------------------------------
- *  Set a liberal script execution time limit
- * ------------------------------------------------------
- */
-	if (function_exists('set_time_limit') && @ini_get('safe_mode') == 0
-		&& php_sapi_name() !== 'cli') // Do not override the Time Limit value if running from Command Line
-	{
-		@set_time_limit(300);
-	}
-
-/*
- * ------------------------------------------------------
  *  Start the timer... tick tock tick tock...
  * ------------------------------------------------------
  */
@@ -143,9 +131,12 @@
 	$CFG =& load_class('Config', 'core');
 
 	// Do we have any manually set config items in the index.php file?
-	if (isset($assign_to_config))
+	if (isset($assign_to_config) && is_array($assign_to_config))
 	{
-		$CFG->_assign_to_config($assign_to_config);
+		foreach ($assign_to_config as $key => $value)
+		{
+			$CFG->set_item($key, $value);
+		}
 	}
 
 /*
@@ -155,7 +146,7 @@
  *
  * Note: Order here is rather important as the UTF-8
  * class needs to be used very early on, but it cannot
- * properly determine if UTf-8 can be supported until
+ * properly determine if UTF-8 can be supported until
  * after the Config class is instantiated.
  *
  */
@@ -195,7 +186,7 @@
  * ------------------------------------------------------
  */
 	if ($EXT->call_hook('cache_override') === FALSE
-		&& $OUT->_display_cache($CFG, $URI) == TRUE)
+		&& $OUT->_display_cache($CFG, $URI) === TRUE)
 	{
 		exit;
 	}
@@ -230,12 +221,18 @@
 	// Load the base controller class
 	require BASEPATH.'core/Controller.php';
 
+	/**
+	 * Reference to the CI_Controller method.
+	 *
+	 * Returns current CI instance object
+	 *
+	 * @return object
+	 */
 	function &get_instance()
 	{
 		return CI_Controller::get_instance();
 	}
 
-
 	if (file_exists(APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php'))
 	{
 		require APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php';
@@ -259,28 +256,27 @@
  *  Security check
  * ------------------------------------------------------
  *
- *  None of the functions in the app controller or the
+ *  None of the methods in the app controller or the
  *  loader class can be called via the URI, nor can
- *  controller functions that begin with an underscore
+ *  controller functions that begin with an underscore.
  */
 	$class  = $RTR->fetch_class();
 	$method = $RTR->fetch_method();
 
-	if ( ! class_exists($class)
-		OR strpos($method, '_') === 0
-		OR in_array(strtolower($method), array_map('strtolower', get_class_methods('CI_Controller')))
-		)
+	if ( ! class_exists($class) OR $method[0] === '_' OR method_exists('CI_Controller', $method))
 	{
 		if ( ! empty($RTR->routes['404_override']))
 		{
-			$x = explode('/', $RTR->routes['404_override'], 2);
-			$class = $x[0];
-			$method = (isset($x[1]) ? $x[1] : 'index');
+			if (sscanf($RTR->routes['404_override'], '%[^/]/%s', $class, $method) !== 2)
+			{
+				$method = 'index';
+			}
+
 			if ( ! class_exists($class))
 			{
 				if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
 				{
-					show_404("{$class}/{$method}");
+					show_404($class.'/'.$method);
 				}
 
 				include_once(APPPATH.'controllers/'.$class.'.php');
@@ -288,10 +284,46 @@
 		}
 		else
 		{
-			show_404("{$class}/{$method}");
+			show_404($class.'/'.$method);
 		}
 	}
 
+	if (method_exists($class, '_remap'))
+	{
+		$params = array($method, array_slice($URI->rsegments, 2));
+		$method = '_remap';
+	}
+	else
+	{
+		// WARNING: It appears that there are issues with is_callable() even in PHP 5.2!
+		// Furthermore, there are bug reports and feature/change requests related to it
+		// that make it unreliable to use in this context. Please, DO NOT change this
+		// work-around until a better alternative is available.
+		if ( ! in_array(strtolower($method), array_map('strtolower', get_class_methods($class)), TRUE))
+		{
+			if (empty($RTR->routes['404_override']))
+			{
+				show_404($class.'/'.$method);
+			}
+			elseif (sscanf($RTR->routes['404_override'], '%[^/]/%s', $class, $method) !== 2)
+			{
+				$method = 'index';
+			}
+
+			if ( ! class_exists($class))
+			{
+				if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
+				{
+					show_404($class.'/'.$method);
+				}
+
+				include_once(APPPATH.'controllers/'.$class.'.php');
+			}
+		}
+
+		$params = array_slice($URI->rsegments, 2);
+	}
+
 /*
  * ------------------------------------------------------
  *  Is there a "pre_controller" hook?
@@ -321,45 +353,7 @@
  *  Call the requested method
  * ------------------------------------------------------
  */
-	// Is there a "remap" function? If so, we call it instead
-	if (method_exists($CI, '_remap'))
-	{
-		$CI->_remap($method, array_slice($URI->rsegments, 2));
-	}
-	else
-	{
-		// is_callable() returns TRUE on some versions of PHP 5 for private and protected
-		// methods, so we'll use this workaround for consistent behavior
-		if ( ! in_array(strtolower($method), array_map('strtolower', get_class_methods($CI))))
-		{
-			// Check and see if we are using a 404 override and use it.
-			if ( ! empty($RTR->routes['404_override']))
-			{
-				$x = explode('/', $RTR->routes['404_override'], 2);
-				$class = $x[0];
-				$method = (isset($x[1]) ? $x[1] : 'index');
-				if ( ! class_exists($class))
-				{
-					if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
-					{
-						show_404("{$class}/{$method}");
-					}
-
-					include_once(APPPATH.'controllers/'.$class.'.php');
-					unset($CI);
-					$CI = new $class();
-				}
-			}
-			else
-			{
-				show_404("{$class}/{$method}");
-			}
-		}
-
-		// Call the requested method.
-		// Any URI segments present (besides the class/function) will be passed to the method for convenience
-		call_user_func_array(array(&$CI, $method), array_slice($URI->rsegments, 2));
-	}
+	call_user_func_array(array(&$CI, $method), $params);
 
 	// Mark a benchmark end point
 	$BM->mark('controller_execution_time_( '.$class.' / '.$method.' )_end');
@@ -388,15 +382,5 @@
  */
 	$EXT->call_hook('post_system');
 
-/*
- * ------------------------------------------------------
- *  Close the DB connection if one exists
- * ------------------------------------------------------
- */
-	if (class_exists('CI_DB') && isset($CI->db))
-	{
-		$CI->db->close();
-	}
-
 /* End of file CodeIgniter.php */
-/* Location: ./system/core/CodeIgniter.php */
+/* Location: ./system/core/CodeIgniter.php */
\ No newline at end of file
diff --git a/system/core/Common.php b/system/core/Common.php
index aeb784bbe..7feb16bfd 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Common Functions
@@ -31,7 +32,7 @@
  * Loads the base classes and executes the request.
  *
  * @package		CodeIgniter
- * @subpackage	codeigniter
+ * @subpackage	CodeIgniter
  * @category	Common Functions
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/
@@ -39,25 +40,25 @@
 
 // ------------------------------------------------------------------------
 
-/**
- * Determines if the current version of PHP is greater then the supplied value
- *
- * Since there are a few places where we conditionally test for PHP > 5
- * we'll set a static variable.
- *
- * @param	string
- * @return	bool	TRUE if the current version is $version or higher
- */
 if ( ! function_exists('is_php'))
 {
-	function is_php($version = '5.0.0')
+	/**
+	 * Determines if the current version of PHP is greater then the supplied value
+	 *
+	 * Since there are a few places where we conditionally test for PHP > 5.3
+	 * we'll set a static variable.
+	 *
+	 * @param	string
+	 * @return	bool	TRUE if the current version is $version or higher
+	 */
+	function is_php($version = '5.3.0')
 	{
 		static $_is_php;
 		$version = (string) $version;
 
 		if ( ! isset($_is_php[$version]))
 		{
-			$_is_php[$version] = (version_compare(PHP_VERSION, $version) < 0) ? FALSE : TRUE;
+			$_is_php[$version] = (version_compare(PHP_VERSION, $version) >= 0);
 		}
 
 		return $_is_php[$version];
@@ -66,18 +67,18 @@ if ( ! function_exists('is_php'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Tests for file writability
- *
- * is_writable() returns TRUE on Windows servers when you really can't write to
- * the file, based on the read-only attribute. is_writable() is also unreliable
- * on Unix servers if safe_mode is on.
- *
- * @param	string
- * @return	void
- */
 if ( ! function_exists('is_really_writable'))
 {
+	/**
+	 * Tests for file writability
+	 *
+	 * is_writable() returns TRUE on Windows servers when you really can't write to
+	 * the file, based on the read-only attribute. is_writable() is also unreliable
+	 * on Unix servers if safe_mode is on.
+	 *
+	 * @param	string
+	 * @return	void
+	 */
 	function is_really_writable($file)
 	{
 		// If we're on a Unix server with safe_mode off we call is_writable
@@ -114,20 +115,20 @@ if ( ! function_exists('is_really_writable'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Class registry
- *
- * This function acts as a singleton. If the requested class does not
- * exist it is instantiated and set to a static variable. If it has
- * previously been instantiated the variable is returned.
- *
- * @param	string	the class name being requested
- * @param	string	the directory where the class should be found
- * @param	string	the class name prefix
- * @return	object
- */
 if ( ! function_exists('load_class'))
 {
+	/**
+	 * Class registry
+	 *
+	 * This function acts as a singleton. If the requested class does not
+	 * exist it is instantiated and set to a static variable. If it has
+	 * previously been instantiated the variable is returned.
+	 *
+	 * @param	string	the class name being requested
+	 * @param	string	the directory where the class should be found
+	 * @param	string	the class name prefix
+	 * @return	object
+	 */
 	function &load_class($class, $directory = 'libraries', $prefix = 'CI_')
 	{
 		static $_classes = array();
@@ -150,7 +151,7 @@ if ( ! function_exists('load_class'))
 
 				if (class_exists($name) === FALSE)
 				{
-					require($path.$directory.'/'.$class.'.php');
+					require_once($path.$directory.'/'.$class.'.php');
 				}
 
 				break;
@@ -164,7 +165,7 @@ 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');
 			}
 		}
 
@@ -172,7 +173,7 @@ if ( ! function_exists('load_class'))
 		if ($name === FALSE)
 		{
 			// Note: We use exit() rather then show_error() in order to avoid a
-			// self-referencing loop with the Excptions class
+			// self-referencing loop with the Exceptions class
 			set_status_header(503);
 			exit('Unable to locate the specified class: '.$class.'.php');
 		}
@@ -187,20 +188,20 @@ if ( ! function_exists('load_class'))
 
 // --------------------------------------------------------------------
 
-/**
- * Keeps track of which libraries have been loaded. This function is
- * called by the load_class() function above
- *
- * @param	string
- * @return	array
- */
 if ( ! function_exists('is_loaded'))
 {
+	/**
+	 * Keeps track of which libraries have been loaded. This function is
+	 * called by the load_class() function above
+	 *
+	 * @param	string
+	 * @return	array
+	 */
 	function &is_loaded($class = '')
 	{
 		static $_is_loaded = array();
 
-		if ($class != '')
+		if ($class !== '')
 		{
 			$_is_loaded[strtolower($class)] = $class;
 		}
@@ -211,17 +212,17 @@ if ( ! function_exists('is_loaded'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Loads the main config.php file
- *
- * This function lets us grab the config file even if the Config class
- * hasn't been instantiated yet
- *
- * @param	array
- * @return	array
- */
 if ( ! function_exists('get_config'))
 {
+	/**
+	 * Loads the main config.php file
+	 *
+	 * This function lets us grab the config file even if the Config class
+	 * hasn't been instantiated yet
+	 *
+	 * @param	array
+	 * @return	array
+	 */
 	function &get_config($replace = array())
 	{
 		static $_config;
@@ -231,21 +232,25 @@ if ( ! function_exists('get_config'))
 			return $_config[0];
 		}
 
-		// Is the config file in the environment folder?
-		if ( ! defined('ENVIRONMENT') OR ! file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config.php'))
+		$file_path = APPPATH.'config/config.php';
+		$found = FALSE;
+		if (file_exists($file_path))
 		{
-			$file_path = APPPATH.'config/config.php';
+			$found = TRUE;
+			require($file_path);
 		}
 
-		// Fetch the config file
-		if ( ! file_exists($file_path))
+		// Is the config file in the environment folder?
+		if (defined('ENVIRONMENT') && file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config.php'))
+		{
+			require($file_path);
+		}
+		elseif ( ! $found)
 		{
 			set_status_header(503);
 			exit('The configuration file does not exist.');
 		}
 
-		require($file_path);
-
 		// Does the $config array exist in the file?
 		if ( ! isset($config) OR ! is_array($config))
 		{
@@ -271,14 +276,14 @@ if ( ! function_exists('get_config'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Returns the specified config item
- *
- * @param	string
- * @return	mixed
- */
 if ( ! function_exists('config_item'))
 {
+	/**
+	 * Returns the specified config item
+	 *
+	 * @param	string
+	 * @return	mixed
+	 */
 	function config_item($item)
 	{
 		static $_config_item = array();
@@ -300,22 +305,66 @@ if ( ! function_exists('config_item'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Error Handler
- *
- * This function lets us invoke the exception class and
- * display errors using the standard error template located
- * in application/errors/errors.php
- * This function will send the error page directly to the
- * browser and exit.
- *
- * @param	string
- * @param	int
- * @param	string
- * @return	void
- */
+if ( ! function_exists('get_mimes'))
+{
+	/**
+	 * Returns the MIME types array from config/mimes.php
+	 *
+	 * @return	array
+	 */
+	function &get_mimes()
+	{
+		static $_mimes = array();
+
+		if (defined('ENVIRONMENT') && is_file(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
+		{
+			$_mimes = include(APPPATH.'config/'.ENVIRONMENT.'/mimes.php');
+		}
+		elseif (is_file(APPPATH.'config/mimes.php'))
+		{
+			$_mimes = include(APPPATH.'config/mimes.php');
+		}
+
+		return $_mimes;
+	}
+}
+
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('is_https'))
+{
+	/**
+	 * Is HTTPS?
+	 *
+	 * Determines if the application is accessed via an encrypted
+	 * (HTTPS) connection.
+	 *
+	 * @return	bool
+	 */
+	function is_https()
+	{
+		return ( ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off');
+	}
+}
+
+// ------------------------------------------------------------------------
+
 if ( ! function_exists('show_error'))
 {
+	/**
+	 * Error Handler
+	 *
+	 * This function lets us invoke the exception class and
+	 * display errors using the standard error template located
+	 * in application/errors/errors.php
+	 * This function will send the error page directly to the
+	 * browser and exit.
+	 *
+	 * @param	string
+	 * @param	int
+	 * @param	string
+	 * @return	void
+	 */
 	function show_error($message, $status_code = 500, $heading = 'An Error Was Encountered')
 	{
 		$_error =& load_class('Exceptions', 'core');
@@ -326,19 +375,19 @@ if ( ! function_exists('show_error'))
 
 // ------------------------------------------------------------------------
 
-/**
- * 404 Page Handler
- *
- * This function is similar to the show_error() function above
- * However, instead of the standard error template it displays
- * 404 errors.
- *
- * @param	string
- * @param	bool
- * @return	void
- */
 if ( ! function_exists('show_404'))
 {
+	/**
+	 * 404 Page Handler
+	 *
+	 * This function is similar to the show_error() function above
+	 * However, instead of the standard error template it displays
+	 * 404 errors.
+	 *
+	 * @param	string
+	 * @param	bool
+	 * @return	void
+	 */
 	function show_404($page = '', $log_error = TRUE)
 	{
 		$_error =& load_class('Exceptions', 'core');
@@ -349,102 +398,107 @@ if ( ! function_exists('show_404'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Error Logging Interface
- *
- * We use this as a simple mechanism to access the logging
- * class and send messages to be logged.
- *
- * @param	string
- * @param	string
- * @param	bool
- * @return	void
- */
 if ( ! function_exists('log_message'))
 {
+	/**
+	 * Error Logging Interface
+	 *
+	 * We use this as a simple mechanism to access the logging
+	 * class and send messages to be logged.
+	 *
+	 * @param	string
+	 * @param	string
+	 * @param	bool
+	 * @return	void
+	 */
 	function log_message($level = 'error', $message, $php_error = FALSE)
 	{
 		static $_log;
 
-		if (config_item('log_threshold') == 0)
+		if (config_item('log_threshold') === 0)
 		{
 			return;
 		}
 
-		$_log =& load_class('Log');
+		$_log =& load_class('Log', 'core');
 		$_log->write_log($level, $message, $php_error);
 	}
 }
 
 // ------------------------------------------------------------------------
 
-/**
- * Set HTTP Status Header
- *
- * @param	int	the status code
- * @param	string
- * @return	void
- */
 if ( ! function_exists('set_status_header'))
 {
+	/**
+	 * Set HTTP Status Header
+	 *
+	 * @param	int	the status code
+	 * @param	string
+	 * @return	void
+	 */
 	function set_status_header($code = 200, $text = '')
 	{
 		$stati = array(
-					200	=> 'OK',
-					201	=> 'Created',
-					202	=> 'Accepted',
-					203	=> 'Non-Authoritative Information',
-					204	=> 'No Content',
-					205	=> 'Reset Content',
-					206	=> 'Partial Content',
-
-					300	=> 'Multiple Choices',
-					301	=> 'Moved Permanently',
-					302	=> 'Found',
-					304	=> 'Not Modified',
-					305	=> 'Use Proxy',
-					307	=> 'Temporary Redirect',
-
-					400	=> 'Bad Request',
-					401	=> 'Unauthorized',
-					403	=> 'Forbidden',
-					404	=> 'Not Found',
-					405	=> 'Method Not Allowed',
-					406	=> 'Not Acceptable',
-					407	=> 'Proxy Authentication Required',
-					408	=> 'Request Timeout',
-					409	=> 'Conflict',
-					410	=> 'Gone',
-					411	=> 'Length Required',
-					412	=> 'Precondition Failed',
-					413	=> 'Request Entity Too Large',
-					414	=> 'Request-URI Too Long',
-					415	=> 'Unsupported Media Type',
-					416	=> 'Requested Range Not Satisfiable',
-					417	=> 'Expectation Failed',
-					422	=> 'Unprocessable Entity',
-
-					500	=> 'Internal Server Error',
-					501	=> 'Not Implemented',
-					502	=> 'Bad Gateway',
-					503	=> 'Service Unavailable',
-					504	=> 'Gateway Timeout',
-					505	=> 'HTTP Version Not Supported'
-			);
-
-		if ($code == '' OR ! is_numeric($code))
+			200	=> 'OK',
+			201	=> 'Created',
+			202	=> 'Accepted',
+			203	=> 'Non-Authoritative Information',
+			204	=> 'No Content',
+			205	=> 'Reset Content',
+			206	=> 'Partial Content',
+
+			300	=> 'Multiple Choices',
+			301	=> 'Moved Permanently',
+			302	=> 'Found',
+			303	=> 'See Other',
+			304	=> 'Not Modified',
+			305	=> 'Use Proxy',
+			307	=> 'Temporary Redirect',
+
+			400	=> 'Bad Request',
+			401	=> 'Unauthorized',
+			403	=> 'Forbidden',
+			404	=> 'Not Found',
+			405	=> 'Method Not Allowed',
+			406	=> 'Not Acceptable',
+			407	=> 'Proxy Authentication Required',
+			408	=> 'Request Timeout',
+			409	=> 'Conflict',
+			410	=> 'Gone',
+			411	=> 'Length Required',
+			412	=> 'Precondition Failed',
+			413	=> 'Request Entity Too Large',
+			414	=> 'Request-URI Too Long',
+			415	=> 'Unsupported Media Type',
+			416	=> 'Requested Range Not Satisfiable',
+			417	=> 'Expectation Failed',
+			422	=> 'Unprocessable Entity',
+
+			500	=> 'Internal Server Error',
+			501	=> 'Not Implemented',
+			502	=> 'Bad Gateway',
+			503	=> 'Service Unavailable',
+			504	=> 'Gateway Timeout',
+			505	=> 'HTTP Version Not Supported'
+		);
+
+		if (empty($code) OR ! is_numeric($code))
 		{
 			show_error('Status codes must be numeric', 500);
 		}
 
-		if (isset($stati[$code]) && $text == '')
-		{
-			$text = $stati[$code];
-		}
+		is_int($code) OR $code = (int) $code;
 
-		if ($text == '')
+		if (empty($text))
 		{
-			show_error('No status text available. Please check your status code number or supply your own message text.', 500);
+			if (isset($stati[$code]))
+			{
+				$text = $stati[$code];
+			}
+			else
+			{
+				show_error('No status text available. Please check your status code number or supply your own message text.', 500);
+			}
 		}
 
 		$server_protocol = isset($_SERVER['SERVER_PROTOCOL']) ? $_SERVER['SERVER_PROTOCOL'] : FALSE;
@@ -453,63 +507,49 @@ if ( ! function_exists('set_status_header'))
 		{
 			header('Status: '.$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);
 		}
 	}
 }
 
 // --------------------------------------------------------------------
 
-/**
- * Exception Handler
- *
- * This is the custom exception handler that is declaired at the top
- * of Codeigniter.php. The main reason we use this is to permit
- * PHP errors to be logged in our own log files since the user may
- * not have access to server logs. Since this function
- * effectively intercepts PHP errors, however, we also need
- * to display errors based on the current error_reporting level.
- * We do that with the use of a PHP error template.
- *
- * @param	int
- * @param	string
- * @param	string
- * @param	int
- * @return	void
- */
 if ( ! function_exists('_exception_handler'))
 {
+	/**
+	 * Exception Handler
+	 *
+	 * This is the custom exception handler that is declaired at the top
+	 * of Codeigniter.php. The main reason we use this is to permit
+	 * PHP errors to be logged in our own log files since the user may
+	 * not have access to server logs. Since this function
+	 * effectively intercepts PHP errors, however, we also need
+	 * to display errors based on the current error_reporting level.
+	 * We do that with the use of a PHP error template.
+	 *
+	 * @param	int
+	 * @param	string
+	 * @param	string
+	 * @param	int
+	 * @return	void
+	 */
 	function _exception_handler($severity, $message, $filepath, $line)
 	{
-		 // We don't bother with "strict" notices since they tend to fill up
-		 // the log file with excess information that isn't normally very helpful.
-		 // For example, if you are running PHP 5 and you use version 4 style
-		 // class functions (without prefixes like "public", "private", etc.)
-		 // you'll get notices telling you that these have been deprecated.
-		if ($severity == E_STRICT)
-		{
-			return;
-		}
-
 		$_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.
-		if (($severity & error_reporting()) == $severity)
+		if (($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);
@@ -518,18 +558,18 @@ if ( ! function_exists('_exception_handler'))
 
 // --------------------------------------------------------------------
 
-/**
- * Remove Invisible Characters
- *
- * This prevents sandwiching null characters
- * between ascii characters, like Java\0script.
- *
- * @param	string
- * @param	bool
- * @return	string
- */
 if ( ! function_exists('remove_invisible_characters'))
 {
+	/**
+	 * Remove Invisible Characters
+	 *
+	 * This prevents sandwiching null characters
+	 * between ascii characters, like Java\0script.
+	 *
+	 * @param	string
+	 * @param	bool
+	 * @return	string
+	 */
 	function remove_invisible_characters($str, $url_encoded = TRUE)
 	{
 		$non_displayables = array();
@@ -556,14 +596,14 @@ if ( ! function_exists('remove_invisible_characters'))
 
 // ------------------------------------------------------------------------
 
-/**
- * Returns HTML escaped variable
- *
- * @param	mixed
- * @return	mixed
- */
 if ( ! function_exists('html_escape'))
 {
+	/**
+	 * Returns HTML escaped variable
+	 *
+	 * @param	mixed
+	 * @return	mixed
+	 */
 	function html_escape($var)
 	{
 		return is_array($var)
@@ -572,5 +612,91 @@ 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, ',');
+	}
+}
+
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('function_usable'))
+{
+	/**
+	 * Function usable
+	 *
+	 * Executes a function_exists() check, and if the Suhosin PHP
+	 * extension is loaded - checks whether the function that is
+	 * checked might be disabled in there as well.
+	 *
+	 * This is useful as function_exists() will return FALSE for
+	 * functions disabled via the *disable_functions* php.ini
+	 * setting, but not for *suhosin.executor.func.blacklist* and
+	 * *suhosin.executor.disable_eval*. These settings will just
+	 * terminate script execution if a disabled function is executed.
+	 *
+	 * @link	http://www.hardened-php.net/suhosin/
+	 * @param	string	$function_name	Function to check for
+	 * @return	bool	TRUE if the function exists and is safe to call,
+	 *			FALSE otherwise.
+	 */
+	function function_usable($function_name)
+	{
+		static $_suhosin_func_blacklist;
+
+		if (function_exists($function_name))
+		{
+			if ( ! isset($_suhosin_func_blacklist))
+			{
+				$_suhosin_func_blacklist = extension_loaded('suhosin')
+					? array()
+					: explode(',', trim(@ini_get('suhosin.executor.func.blacklist')));
+
+				if ( ! in_array('eval', $_suhosin_func_blacklist, TRUE) && @ini_get('suhosin.executor.disable_eval'))
+				{
+					$_suhosin_func_blacklist[] = 'eval';
+				}
+			}
+
+			return in_array($function_name, $_suhosin_func_blacklist, TRUE);
+		}
+
+		return FALSE;
+	}
+}
+
 /* 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 91826bd41..38bcd5c8f 100755..100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,11 +24,10 @@
  * @since		Version 1.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
- * CodeIgniter Config Class
+ * Config Class
  *
  * This class contains functions that enable config files to be managed
  *
@@ -43,32 +42,31 @@ class CI_Config {
 	/**
 	 * List of all loaded config values
 	 *
-	 * @var array
+	 * @var	array
 	 */
 	public $config = array();
+
 	/**
 	 * List of all loaded config files
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $is_loaded = array();
+	public $is_loaded =	array();
+
 	/**
 	 * List of paths to search when trying to load a config file.
-	 * This must be public as it's used by the Loader class.
 	 *
-	 * @var array
+	 * @used-by	CI_Loader
+	 * @var		array
 	 */
-	public $_config_paths = array(APPPATH);
+	public $_config_paths =	array(APPPATH);
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
-	 * Sets the $config data from the primary config.php file as a class variable
+	 * Sets the $config data from the primary config.php file as a class variable.
 	 *
-	 * @param   string	the config file name
-	 * @param   boolean  if configuration values should be loaded into their own section
-	 * @param   boolean  true if errors should just return false, false if an error message should be displayed
-	 * @return  boolean  if the file was successfully loaded or not
+	 * @return	void
 	 */
 	public function __construct()
 	{
@@ -80,9 +78,9 @@ class CI_Config {
 		{
 			if (isset($_SERVER['HTTP_HOST']))
 			{
-				$base_url = ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off' ? 'https' : 'http';
-				$base_url .= '://'. $_SERVER['HTTP_HOST']
-					. str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);
+				$base_url = is_https() ? 'https' : 'http';
+				$base_url .= '://'.$_SERVER['HTTP_HOST']
+					.str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);
 			}
 			else
 			{
@@ -98,22 +96,22 @@ class CI_Config {
 	/**
 	 * Load Config File
 	 *
-	 * @param	string	the config file name
-	 * @param	boolean	if configuration values should be loaded into their own section
-	 * @param	boolean	true if errors should just return false, false if an error message should be displayed
-	 * @return	boolean	if the file was loaded correctly
+	 * @param	string	$file			Configuration file name
+	 * @param	bool	$use_sections		Whether configuration values should be loaded into their own section
+	 * @param	bool	$fail_gracefully	Whether to just return FALSE or display an error message
+	 * @return	bool	TRUE if the file was loaded correctly or FALSE on failure
 	 */
 	public function load($file = '', $use_sections = FALSE, $fail_gracefully = FALSE)
 	{
-		$file = ($file == '') ? 'config' : str_replace('.php', '', $file);
+		$file = ($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)
 		{
-			$check_locations = defined('ENVIRONMENT')
-				? array(ENVIRONMENT.'/'.$file, $file)
-				: array($file);
-
 			foreach ($check_locations as $location)
 			{
 				$file_path = $path.'config/'.$location.'.php';
@@ -177,7 +175,7 @@ class CI_Config {
 			{
 				return FALSE;
 			}
-			show_error('The configuration file '.$file.'.php'.' does not exist.');
+			show_error('The configuration file '.$file.'.php does not exist.');
 		}
 
 		return TRUE;
@@ -188,11 +186,9 @@ class CI_Config {
 	/**
 	 * Fetch a config file item
 	 *
-	 *
-	 * @param	string	the config item name
-	 * @param	string	the index name
-	 * @param	bool
-	 * @return	string
+	 * @param	string	$item	Config item name
+	 * @param	string	$index	Index name
+	 * @return	string|bool	The configuration item or FALSE on failure
 	 */
 	public function item($item, $index = '')
 	{
@@ -207,11 +203,10 @@ class CI_Config {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch a config file item - adds slash after item (if item is not empty)
+	 * Fetch a config file item with slash appended (if not empty)
 	 *
-	 * @param	string	the config item name
-	 * @param	bool
-	 * @return	string
+	 * @param	string		$item	Config item name
+	 * @return	string|bool	The configuration item or FALSE on failure
 	 */
 	public function slash_item($item)
 	{
@@ -219,7 +214,7 @@ class CI_Config {
 		{
 			return FALSE;
 		}
-		elseif (trim($this->config[$item]) == '')
+		elseif (trim($this->config[$item]) === '')
 		{
 			return '';
 		}
@@ -231,54 +226,80 @@ class CI_Config {
 
 	/**
 	 * Site URL
+	 *
 	 * Returns base_url . index_page [. uri_string]
 	 *
-	 * @param	string	the URI string
+	 * @uses	CI_Config::_uri_string()
+	 *
+	 * @param	string|string[]	$uri	URI string or an array of segments
 	 * @return	string
 	 */
 	public function site_url($uri = '')
 	{
-		if ($uri == '')
+		if (empty($uri))
 		{
 			return $this->slash_item('base_url').$this->item('index_page');
 		}
 
-		if ($this->item('enable_query_strings') == FALSE)
+		$uri = $this->_uri_string($uri);
+
+		if ($this->item('enable_query_strings') === FALSE)
 		{
-			$suffix = ($this->item('url_suffix') == FALSE) ? '' : $this->item('url_suffix');
-			return $this->slash_item('base_url').$this->slash_item('index_page').$this->_uri_string($uri).$suffix;
+			$suffix = isset($this->config['url_suffix']) ? $this->config['url_suffix'] : '';
+
+			if ($suffix !== '')
+			{
+				if (($offset = strpos($uri, '?')) !== FALSE)
+				{
+					$uri = substr($uri, 0, $offset).$suffix.substr($uri, $offset);
+				}
+				else
+				{
+					$uri .= $suffix;
+				}
+			}
+
+			return $this->slash_item('base_url').$this->slash_item('index_page').$uri;
 		}
-		else
+		elseif (strpos($uri, '?') === FALSE)
 		{
-			return $this->slash_item('base_url').$this->item('index_page').'?'.$this->_uri_string($uri);
+			$uri = '?'.$uri;
 		}
+
+		return $this->slash_item('base_url').$this->item('index_page').$uri;
 	}
 
 	// -------------------------------------------------------------
 
 	/**
 	 * Base URL
+	 *
 	 * Returns base_url [. uri_string]
 	 *
-	 * @param string $uri
-	 * @return string
+	 * @uses	CI_Config::_uri_string()
+	 *
+	 * @param	string|string[]	$uri	URI string or an array of segments
+	 * @return	string
 	 */
 	public function base_url($uri = '')
 	{
-		return $this->slash_item('base_url').ltrim($this->_uri_string($uri),'/');
+		return $this->slash_item('base_url').ltrim($this->_uri_string($uri), '/');
 	}
 
 	// -------------------------------------------------------------
 
 	/**
-	 * Build URI string for use in Config::site_url() and Config::base_url()
+	 * Build URI string
+	 *
+	 * @used-by	CI_Config::site_url()
+	 * @used-by	CI_Config::base_url()
 	 *
-	 * @param  mixed $uri
-	 * @return string
+	 * @param	string|string[]	$uri	URI string or an array of segments
+	 * @return	string
 	 */
 	protected function _uri_string($uri)
 	{
-		if ($this->item('enable_query_strings') == FALSE)
+		if ($this->item('enable_query_strings') === FALSE)
 		{
 			if (is_array($uri))
 			{
@@ -288,15 +309,7 @@ class CI_Config {
 		}
 		elseif (is_array($uri))
 		{
-			$i = 0;
-			$str = '';
-			foreach ($uri as $key => $val)
-			{
-				$prefix = ($i === 0) ? '' : '&';
-				$str .= $prefix.$key.'='.$val;
-				$i++;
-			}
-			return $str;
+			return http_build_query($uri);
 		}
 
 		return $uri;
@@ -320,8 +333,8 @@ class CI_Config {
 	/**
 	 * Set a config file item
 	 *
-	 * @param	string	the config item key
-	 * @param	string	the config item value
+	 * @param	string	$item	Config item key
+	 * @param	string	$value	Config item value
 	 * @return	void
 	 */
 	public function set_item($item, $value)
@@ -329,29 +342,7 @@ class CI_Config {
 		$this->config[$item] = $value;
 	}
 
-	// --------------------------------------------------------------------
-
-	/**
-	 * Assign to Config
-	 *
-	 * This function is called by the front controller (CodeIgniter.php)
-	 * after the Config class is instantiated. It permits config items
-	 * to be assigned or overriden by variables contained in the index.php file
-	 *
-	 * @param	array
-	 * @return	void
-	 */
-	public function _assign_to_config($items = array())
-	{
-		if (is_array($items))
-		{
-			foreach ($items as $key => $val)
-			{
-				$this->set_item($key, $val);
-			}
-		}
-	}
 }
 
 /* End of file Config.php */
-/* Location: ./system/core/Config.php */
+/* Location: ./system/core/Config.php */
\ No newline at end of file
diff --git a/system/core/Controller.php b/system/core/Controller.php
index 05e1bf5bf..ee6fec8d5 100644
--- a/system/core/Controller.php
+++ b/system/core/Controller.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,11 +24,10 @@
  * @since		Version 1.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
- * CodeIgniter Application Controller Class
+ * Application Controller Class
  *
  * This class object is the super class that every library in
  * CodeIgniter will be assigned to.
@@ -41,8 +40,18 @@
  */
 class CI_Controller {
 
+	/**
+	 * Reference to the CI singleton
+	 *
+	 * @var	object
+	 */
 	private static $instance;
 
+	/**
+	 * Class constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		self::$instance =& $this;
@@ -60,11 +69,20 @@ class CI_Controller {
 		log_message('debug', 'Controller Class Initialized');
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Get the CI singleton
+	 *
+	 * @static
+	 * @return	object
+	 */
 	public static function &get_instance()
 	{
 		return self::$instance;
 	}
+
 }
 
 /* End of file Controller.php */
-/* Location: ./system/core/Controller.php */
+/* Location: ./system/core/Controller.php */
\ No newline at end of file
diff --git a/system/core/Exceptions.php b/system/core/Exceptions.php
index f36b31598..ced65ece4 100755..100644
--- a/system/core/Exceptions.php
+++ b/system/core/Exceptions.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Exceptions Class
@@ -36,39 +37,38 @@
  */
 class CI_Exceptions {
 
-	public $action;
-	public $severity;
-	public $message;
-	public $filename;
-	public $line;
-
 	/**
 	 * Nesting level of the output buffering mechanism
 	 *
-	 * @var int
+	 * @var	int
 	 */
 	public $ob_level;
 
 	/**
 	 * List if available error levels
 	 *
-	 * @var array
+	 * @var	array
 	 */
 	public $levels = array(
-				E_ERROR			=>	'Error',
-				E_WARNING		=>	'Warning',
-				E_PARSE			=>	'Parsing Error',
-				E_NOTICE		=>	'Notice',
-				E_CORE_ERROR		=>	'Core Error',
-				E_CORE_WARNING		=>	'Core Warning',
-				E_COMPILE_ERROR		=>	'Compile Error',
-				E_COMPILE_WARNING	=>	'Compile Warning',
-				E_USER_ERROR		=>	'User Error',
-				E_USER_WARNING		=>	'User Warning',
-				E_USER_NOTICE		=>	'User Notice',
-				E_STRICT		=>	'Runtime Notice'
-			);
+		E_ERROR			=>	'Error',
+		E_WARNING		=>	'Warning',
+		E_PARSE			=>	'Parsing Error',
+		E_NOTICE		=>	'Notice',
+		E_CORE_ERROR		=>	'Core Error',
+		E_CORE_WARNING		=>	'Core Warning',
+		E_COMPILE_ERROR		=>	'Compile Error',
+		E_COMPILE_WARNING	=>	'Compile Warning',
+		E_USER_ERROR		=>	'User Error',
+		E_USER_WARNING		=>	'User Warning',
+		E_USER_NOTICE		=>	'User Notice',
+		E_STRICT		=>	'Runtime Notice'
+	);
 
+	/**
+	 * Class constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		$this->ob_level = ob_get_level();
@@ -80,28 +80,30 @@ class CI_Exceptions {
 	/**
 	 * Exception Logger
 	 *
-	 * This function logs PHP generated error messages
+	 * Logs PHP generated error messages
 	 *
-	 * @param	string	the error severity
-	 * @param	string	the error string
-	 * @param	string	the error filepath
-	 * @param	string	the error line number
+	 * @param	int	$severity	Log level
+	 * @param	string	$message	Error message
+	 * @param	string	$filepath	File path
+	 * @param	int	$line		Line number
 	 * @return	void
 	 */
 	public function log_exception($severity, $message, $filepath, $line)
 	{
-		$severity = ( ! isset($this->levels[$severity])) ? $severity : $this->levels[$severity];
+		$severity = isset($this->levels[$severity]) ? $this->levels[$severity] : $severity;
 		log_message('error', 'Severity: '.$severity.'  --> '.$message. ' '.$filepath.' '.$line, TRUE);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * 404 Page Not Found Handler
+	 * 404 Error Handler
+	 *
+	 * @uses	CI_Exceptions::show_error()
 	 *
-	 * @param	string	the page
-	 * @param 	bool	log error yes/no
-	 * @return	string
+	 * @param	string	$page		Page URI
+	 * @param 	bool	$log_error	Whether to log the error
+	 * @return	void
 	 */
 	public function show_404($page = '', $log_error = TRUE)
 	{
@@ -123,28 +125,28 @@ class CI_Exceptions {
 	/**
 	 * General Error Page
 	 *
-	 * This function takes an error message as input
-	 * (either as a string or an array) and displays
-	 * it using the specified template.
+	 * Takes an error message as input (either as a string or an array)
+	 * and displays it using the specified template.
+	 *
+	 * @param	string		$heading	Page heading
+	 * @param	string|string[]	$message	Error message
+	 * @param	string		$template	Template name
+	 * @param 	int		$status_code	(default: 500)
 	 *
-	 * @param	string	the heading
-	 * @param	string	the message
-	 * @param	string	the template name
-	 * @param 	int		the status code
-	 * @return	string
+	 * @return	string	Error page output
 	 */
 	public function show_error($heading, $message, $template = 'error_general', $status_code = 500)
 	{
 		set_status_header($status_code);
 
-		$message = '<p>'.implode('</p><p>', ( ! is_array($message)) ? array($message) : $message).'</p>';
+		$message = '<p>'.implode('</p><p>', is_array($message) ? $message : array($message)).'</p>';
 
 		if (ob_get_level() > $this->ob_level + 1)
 		{
 			ob_end_flush();
 		}
 		ob_start();
-		include(APPPATH.'errors/'.$template.'.php');
+		include(VIEWPATH.'errors/'.$template.'.php');
 		$buffer = ob_get_contents();
 		ob_end_clean();
 		return $buffer;
@@ -155,15 +157,15 @@ class CI_Exceptions {
 	/**
 	 * Native PHP error handler
 	 *
-	 * @param	string	the error severity
-	 * @param	string	the error string
-	 * @param	string	the error filepath
-	 * @param	string	the error line number
-	 * @return	string
+	 * @param	int	$severity	Error level
+	 * @param	string	$message	Error message
+	 * @param	string	$filepath	File path
+	 * @param	int	$line		Line number
+	 * @return	string	Error page output
 	 */
 	public function show_php_error($severity, $message, $filepath, $line)
 	{
-		$severity = ( ! isset($this->levels[$severity])) ? $severity : $this->levels[$severity];
+		$severity = isset($this->levels[$severity]) ? $this->levels[$severity] : $severity;
 		$filepath = str_replace('\\', '/', $filepath);
 
 		// For safety reasons we do not show the full file path
@@ -178,7 +180,7 @@ class CI_Exceptions {
 			ob_end_flush();
 		}
 		ob_start();
-		include(APPPATH.'errors/'.'error_php.php');
+		include(VIEWPATH.'errors/error_php.php');
 		$buffer = ob_get_contents();
 		ob_end_clean();
 		echo $buffer;
diff --git a/system/core/Hooks.php b/system/core/Hooks.php
index 68e30ef0f..3c28ec9ba 100755..100644
--- a/system/core/Hooks.php
+++ b/system/core/Hooks.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,9 +24,10 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
- * CodeIgniter Hooks Class
+ * Hooks Class
  *
  * Provides a mechanism to extend the base system without hacking.
  *
@@ -39,26 +40,30 @@
 class CI_Hooks {
 
 	/**
-	 * Determines wether hooks are enabled
+	 * Determines whether hooks are enabled
 	 *
-	 * @var bool
+	 * @var	bool
 	 */
-	public $enabled		= FALSE;
+	public $enabled = FALSE;
+
 	/**
 	 * List of all hooks set in config/hooks.php
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $hooks		= array();
+	public $hooks =	array();
+
 	/**
-	 * Determines wether hook is in progress, used to prevent infinte loops
+	 * In progress flag
+	 *
+	 * Determines whether hook is in progress, used to prevent infinte loops
 	 *
-	 * @var bool
+	 * @var	bool
 	 */
-	public $in_progress	= FALSE;
+	protected $_in_progress = FALSE;
 
 	/**
-	 * Initialize the Hooks Preferences
+	 * Class constructor
 	 *
 	 * @return	void
 	 */
@@ -70,7 +75,7 @@ class CI_Hooks {
 
 		// If hooks are not enabled in the config file
 		// there is nothing else to do
-		if ($CFG->item('enable_hooks') == FALSE)
+		if ($CFG->item('enable_hooks') === FALSE)
 		{
 			return;
 		}
@@ -102,8 +107,10 @@ class CI_Hooks {
 	 *
 	 * Calls a particular hook. Called by CodeIgniter.php.
 	 *
-	 * @param	string	the hook name
-	 * @return	mixed
+	 * @uses	CI_Hooks::_run_hook()
+	 *
+	 * @param	string	$which	Hook name
+	 * @return	bool	TRUE on success or FALSE on failure
 	 */
 	public function call_hook($which = '')
 	{
@@ -134,8 +141,8 @@ class CI_Hooks {
 	 *
 	 * Runs a particular hook
 	 *
-	 * @param	array	the hook details
-	 * @return	bool
+	 * @param	array	$data	Hook details
+	 * @return	bool	TRUE on success or FALSE on failure
 	 */
 	protected function _run_hook($data)
 	{
@@ -150,7 +157,7 @@ class CI_Hooks {
 
 		// If the script being called happens to have the same
 		// hook call within it a loop can happen
-		if ($this->in_progress == TRUE)
+		if ($this->_in_progress === TRUE)
 		{
 			return;
 		}
@@ -171,44 +178,20 @@ class CI_Hooks {
 			return FALSE;
 		}
 
-		// -----------------------------------
-		// Set class/function name
-		// -----------------------------------
-
-		$class		= FALSE;
-		$function	= FALSE;
-		$params		= '';
-
-		if ( ! empty($data['class']))
-		{
-			$class = $data['class'];
-		}
-
-		if ( ! empty($data['function']))
-		{
-			$function = $data['function'];
-		}
-
-		if (isset($data['params']))
-		{
-			$params = $data['params'];
-		}
+		// Determine and class and/or function names
+		$class		= empty($data['class']) ? FALSE : $data['class'];
+		$function	= empty($data['function']) ? FALSE : $data['function'];
+		$params		= isset($data['params']) ? $data['params'] : '';
 
 		if ($class === FALSE && $function === FALSE)
 		{
 			return FALSE;
 		}
 
-		// -----------------------------------
-		// Set the in_progress flag
-		// -----------------------------------
-
-		$this->in_progress = TRUE;
+		// Set the _in_progress flag
+		$this->_in_progress = TRUE;
 
-		// -----------------------------------
 		// Call the requested class and/or function
-		// -----------------------------------
-
 		if ($class !== FALSE)
 		{
 			if ( ! class_exists($class))
@@ -216,7 +199,7 @@ class CI_Hooks {
 				require($filepath);
 			}
 
-			$HOOK = new $class;
+			$HOOK = new $class();
 			$HOOK->$function($params);
 		}
 		else
@@ -229,7 +212,7 @@ class CI_Hooks {
 			$function($params);
 		}
 
-		$this->in_progress = FALSE;
+		$this->_in_progress = FALSE;
 		return TRUE;
 	}
 
diff --git a/system/core/Input.php b/system/core/Input.php
index 6e6885992..a3ad14e24 100755..100644
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Input Class
@@ -41,53 +42,80 @@ class CI_Input {
 	/**
 	 * IP address of the current user
 	 *
-	 * @var string
+	 * @var	string
 	 */
-	public $ip_address				= FALSE;
+	public $ip_address = FALSE;
+
 	/**
-	 * user agent (web browser) being used by the current user
+	 * User agent strin
 	 *
-	 * @var string
+	 * @var	string
 	 */
-	public $user_agent				= FALSE;
+	public $user_agent = FALSE;
+
 	/**
-	 * If FALSE, then $_GET will be set to an empty array
+	 * Allow GET array flag
+	 *
+	 * If set to FALSE, then $_GET will be set to an empty array.
 	 *
-	 * @var bool
+	 * @var	bool
 	 */
-	protected $_allow_get_array		= TRUE;
+	protected $_allow_get_array = TRUE;
+
 	/**
-	 * If TRUE, then newlines are standardized
+	 * Standartize new lines flag
+	 *
+	 * If set to TRUE, then newlines are standardized.
 	 *
-	 * @var bool
+	 * @var	bool
 	 */
-	protected $_standardize_newlines	= TRUE;
+	protected $_standardize_newlines = TRUE;
+
 	/**
-	 * Determines whether the XSS filter is always active when GET, POST or COOKIE data is encountered
-	 * Set automatically based on config setting
+	 * Enable XSS flag
+	 *
+	 * Determines whether the XSS filter is always active when
+	 * GET, POST or COOKIE data is encountered.
+	 * Set automatically based on config setting.
 	 *
-	 * @var bool
+	 * @var	bool
 	 */
-	protected $_enable_xss			= FALSE;
+	protected $_enable_xss = FALSE;
+
 	/**
+	 * Enable CSRF flag
+	 *
 	 * Enables a CSRF cookie token to be set.
-	 * Set automatically based on config setting
+	 * Set automatically based on config setting.
 	 *
-	 * @var bool
+	 * @var	bool
 	 */
-	protected $_enable_csrf			= FALSE;
+	protected $_enable_csrf = FALSE;
+
 	/**
 	 * List of all HTTP request headers
 	 *
 	 * @var array
 	 */
-	protected $headers			= array();
+	protected $headers = array();
 
 	/**
-	 * Constructor
+	 * Input stream data
 	 *
-	 * Sets whether to globally enable the XSS processing
-	 * and whether to allow the $_GET array
+	 * Parsed from php://input at runtime
+	 *
+	 * @see	CI_Input::input_stream()
+	 * @var	array
+	 */
+	protected $_input_stream = NULL;
+
+	/**
+	 * Class constructor
+	 *
+	 * Determines whether to globally enable the XSS processing
+	 * and whether to allow the $_GET array.
+	 *
+	 * @return	void
 	 */
 	public function __construct()
 	{
@@ -116,18 +144,18 @@ class CI_Input {
 	/**
 	 * Fetch from array
 	 *
-	 * This is a helper function to retrieve values from global arrays
+	 * Internal method used to retrieve values from global arrays.
 	 *
-	 * @param	array
-	 * @param	string
-	 * @param	bool
-	 * @return	string
+	 * @param	array	&$array		$_GET, $_POST, $_COOKIE, $_SERVER, etc.
+	 * @param	string	$index		Index for item to be fetched from $array
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
 	 */
 	protected function _fetch_from_array(&$array, $index = '', $xss_clean = FALSE)
 	{
 		if ( ! isset($array[$index]))
 		{
-			return FALSE;
+			return NULL;
 		}
 
 		if ($xss_clean === TRUE)
@@ -141,17 +169,22 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	* Fetch an item from the GET array
-	*
-	* @param	string
-	* @param	bool
-	* @return	string
-	*/
+	 * Fetch an item from the GET array
+	 *
+	 * @param	string	$index		Index for item to be fetched from $_GET
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
+	 */
 	public function get($index = NULL, $xss_clean = FALSE)
 	{
 		// Check if a field has been provided
-		if ($index === NULL && ! empty($_GET))
+		if ($index === NULL)
 		{
+			if (empty($_GET))
+			{
+				return array();
+			}
+
 			$get = array();
 
 			// loop through the full _GET array
@@ -168,17 +201,22 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	* Fetch an item from the POST array
-	*
-	* @param	string
-	* @param	bool
-	* @return	string
-	*/
+	 * Fetch an item from the POST array
+	 *
+	 * @param	string	$index		Index for item to be fetched from $_POST
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
+	 */
 	public function post($index = NULL, $xss_clean = FALSE)
 	{
 		// Check if a field has been provided
-		if ($index === NULL && ! empty($_POST))
+		if ($index === NULL)
 		{
+			if (empty($_POST))
+			{
+				return array();
+			}
+
 			$post = array();
 
 			// Loop through the full _POST array and return it
@@ -192,16 +230,15 @@ class CI_Input {
 		return $this->_fetch_from_array($_POST, $index, $xss_clean);
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
-	* Fetch an item from either the GET array or the POST
-	*
-	* @param	string	The index key
-	* @param	bool	XSS cleaning
-	* @return	string
-	*/
+	 * Fetch an item from POST data with fallback to GET
+	 *
+	 * @param	string	$index		Index for item to be fetched from $_POST or $_GET
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
+	 */
 	public function get_post($index = '', $xss_clean = FALSE)
 	{
 		return isset($_POST[$index])
@@ -212,35 +249,80 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	* Fetch an item from the COOKIE array
-	*
-	* @param	string
-	* @param	bool
-	* @return	string
-	*/
+	 * Fetch an item from the COOKIE array
+	 *
+	 * @param	string	$index		Index for item to be fetched from $_COOKIE
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
+	 */
 	public function cookie($index = '', $xss_clean = FALSE)
 	{
 		return $this->_fetch_from_array($_COOKIE, $index, $xss_clean);
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch an item from the SERVER array
+	 *
+	 * @param	string	$index		Index for item to be fetched from $_SERVER
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
+	 */
+	public function server($index = '', $xss_clean = FALSE)
+	{
+		return $this->_fetch_from_array($_SERVER, $index, $xss_clean);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch an item from the php://input stream
+	 *
+	 * Useful when you need to access PUT, DELETE or PATCH request data.
+	 *
+	 * @param	string	$index		Index for item to be fetched
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
+	 * @return	mixed
+	 */
+	public function input_stream($index = '', $xss_clean = FALSE)
+	{
+		// The input stream can only be read once, so we'll need to check
+		// if we have already done that first.
+		if (is_array($this->_input_stream))
+		{
+			return $this->_fetch_from_array($this->_input_stream, $index, $xss_clean);
+		}
+
+		// Parse the input stream in our cache var
+		parse_str(file_get_contents('php://input'), $this->_input_stream);
+		if ( ! is_array($this->_input_stream))
+		{
+			$this->_input_stream = array();
+			return NULL;
+		}
+
+		return $this->_fetch_from_array($this->_input_stream, $index, $xss_clean);
+	}
+
 	// ------------------------------------------------------------------------
 
 	/**
-	* Set cookie
-	*
-	* Accepts seven parameters, or you can submit an associative
-	* array in the first parameter containing all the values.
-	*
-	* @param	mixed
-	* @param	string	the value of the cookie
-	* @param	string	the number of seconds until expiration
-	* @param	string	the cookie domain.  Usually:  .yourdomain.com
-	* @param	string	the cookie path
-	* @param	string	the cookie prefix
-	* @param	bool	true makes the cookie secure
-	* @param	bool	true makes the cookie accessible via http(s) only (no javascript)
-	* @return	void
-	*/
+	 * Set cookie
+	 *
+	 * Accepts an arbitrary number of parameters (up to 7) or an associative
+	 * array in the first parameter containing all the values.
+	 *
+	 * @param	string|mixed[]	$name		Cookie name or an array containing parameters
+	 * @param	string		$value		Cookie value
+	 * @param	int		$expire		Cookie expiration time in seconds
+	 * @param	string		$domain		Cookie domain (e.g.: '.yourdomain.com')
+	 * @param	string		$path		Cookie path (default: '/')
+	 * @param	string		$prefix		Cookie name prefix
+	 * @param	bool		$secure		Whether to only transfer cookies via SSL
+	 * @param	bool		$httponly	Whether to only makes the cookie accessible via HTTP (no javascript)
+	 * @return	void
+	 */
 	public function set_cookie($name = '', $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = FALSE, $httponly = FALSE)
 	{
 		if (is_array($name))
@@ -255,23 +337,27 @@ class CI_Input {
 			}
 		}
 
-		if ($prefix == '' && config_item('cookie_prefix') != '')
+		if ($prefix === '' && config_item('cookie_prefix') !== '')
 		{
 			$prefix = config_item('cookie_prefix');
 		}
+
 		if ($domain == '' && config_item('cookie_domain') != '')
 		{
 			$domain = config_item('cookie_domain');
 		}
-		if ($path == '/' && config_item('cookie_path') !== '/')
+
+		if ($path === '/' && config_item('cookie_path') !== '/')
 		{
 			$path = config_item('cookie_path');
 		}
-		if ($secure == FALSE && config_item('cookie_secure') != FALSE)
+
+		if ($secure === FALSE && config_item('cookie_secure') !== FALSE)
 		{
 			$secure = config_item('cookie_secure');
 		}
-		if ($httponly == FALSE && config_item('cookie_httponly') != FALSE)
+
+		if ($httponly === FALSE && config_item('cookie_httponly') !== FALSE)
 		{
 			$httponly = config_item('cookie_httponly');
 		}
@@ -291,24 +377,12 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	* Fetch an item from the SERVER array
-	*
-	* @param	string
-	* @param	bool
-	* @return	string
-	*/
-	public function server($index = '', $xss_clean = FALSE)
-	{
-		return $this->_fetch_from_array($_SERVER, $index, $xss_clean);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	* Fetch the IP Address
-	*
-	* @return	string
-	*/
+	 * Fetch the IP Address
+	 *
+	 * Determines and validates the visitor's IP address.
+	 *
+	 * @return	string	IP address
+	 */
 	public function ip_address()
 	{
 		if ($this->ip_address !== FALSE)
@@ -316,39 +390,117 @@ 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.
+					sscanf($spoof, '%[^,]', $spoof);
+
+					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, $ip);
+					}
+
+					// Split the netmask length off the network address
+					sscanf($proxy_ips[$i], '%[^/]/%d', $netaddr, $masklen);
+
+					// Again, an IPv6 address is most likely in a compressed form
+					if ($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))
@@ -362,25 +514,37 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	* Validate IP Address
-	*
-	* Updated version suggested by Geert De Deckere
-	*
-	* @param	string
-	* @return	bool
-	*/
-	public function valid_ip($ip)
+	 * Validate IP Address
+	 *
+	 * @param	string	$ip	IP address
+	 * @param	string	$which	IP protocol: 'ipv4' or 'ipv6'
+	 * @return	bool
+	 */
+	public function valid_ip($ip, $which = '')
 	{
-		return (bool) filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4);
+		switch (strtolower($which))
+		{
+			case 'ipv4':
+				$which = FILTER_FLAG_IPV4;
+				break;
+			case 'ipv6':
+				$which = FILTER_FLAG_IPV6;
+				break;
+			default:
+				$which = NULL;
+				break;
+		}
+
+		return (bool) filter_var($ip, FILTER_VALIDATE_IP, $which);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	* User Agent
-	*
-	* @return	string
-	*/
+	 * Fetch User Agent string
+	 *
+	 * @return	string|null	User Agent string or NULL if it doesn't exist
+	 */
 	public function user_agent()
 	{
 		if ($this->user_agent !== FALSE)
@@ -388,58 +552,75 @@ class CI_Input {
 			return $this->user_agent;
 		}
 
-		return $this->user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : FALSE;
+		return $this->user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : NULL;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	* Sanitize Globals
-	*
-	* This function does the following:
-	*
-	* - Unsets $_GET data (if query strings are not enabled)
-	* - Unsets all globals if register_globals is enabled
-	* - Standardizes newline characters to \n
-	*
-	* @return	void
-	*/
+	 * Sanitize Globals
+	 *
+	 * Internal method serving for the following purposes:
+	 *
+	 *	- Unsets $_GET data (if query strings are not enabled)
+	 *	- Unsets all globals if register_globals is enabled
+	 *	- Cleans POST, COOKIE and SERVER data
+	 * 	- Standardizes newline characters to PHP_EOL
+	 *
+	 * @return	void
+	 */
 	protected function _sanitize_globals()
 	{
 		// It would be "wrong" to unset any of these GLOBALS.
-		$protected = array('_SERVER', '_GET', '_POST', '_FILES', '_REQUEST',
-					'_SESSION', '_ENV', 'GLOBALS', 'HTTP_RAW_POST_DATA',
-					'system_folder', 'application_folder', 'BM', 'EXT',
-					'CFG', 'URI', 'RTR', 'OUT', 'IN'
-				);
-
-		// Unset globals for securiy.
+		$protected = array(
+			'_SERVER',
+			'_GET',
+			'_POST',
+			'_FILES',
+			'_REQUEST',
+			'_SESSION',
+			'_ENV',
+			'GLOBALS',
+			'HTTP_RAW_POST_DATA',
+			'system_folder',
+			'application_folder',
+			'BM',
+			'EXT',
+			'CFG',
+			'URI',
+			'RTR',
+			'OUT',
+			'IN'
+		);
+
+		// Unset globals for security.
 		// This is effectively the same as register_globals = off
-		foreach (array($_GET, $_POST, $_COOKIE) as $global)
+		// PHP 5.4 no longer has the register_globals functionality.
+		if ( ! is_php('5.4'))
 		{
-			if ( ! is_array($global))
+			foreach (array($_GET, $_POST, $_COOKIE) as $global)
 			{
-				if ( ! in_array($global, $protected))
+				if (is_array($global))
 				{
-					global $$global;
-					$$global = NULL;
-				}
-			}
-			else
-			{
-				foreach ($global as $key => $val)
-				{
-					if ( ! in_array($key, $protected))
+					foreach ($global as $key => $val)
 					{
-						global $$key;
-						$$key = NULL;
+						if ( ! in_array($key, $protected))
+						{
+							global $$key;
+							$$key = NULL;
+						}
 					}
 				}
+				elseif ( ! in_array($global, $protected))
+				{
+					global $$global;
+					$$global = NULL;
+				}
 			}
 		}
 
 		// Is $_GET data allowed? If not we'll set the $_GET to an empty array
-		if ($this->_allow_get_array == FALSE)
+		if ($this->_allow_get_array === FALSE)
 		{
 			$_GET = array();
 		}
@@ -482,7 +663,7 @@ 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();
 		}
@@ -493,22 +674,22 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	* Clean Input Data
-	*
-	* This is a helper function. It escapes data and
-	* standardizes newline characters to \n
-	*
-	* @param	string
-	* @return	string
-	*/
+	 * Clean Input Data
+	 *
+	 * Internal method that aids in escaping data and
+	 * standardizing newline characters to PHP_EOL.
+	 *
+	 * @param	string|string[]	$str	Input string(s)
+	 * @return	string
+	 */
 	protected function _clean_input_data($str)
 	{
 		if (is_array($str))
 		{
 			$new_array = array();
-			foreach ($str as $key => $val)
+			foreach (array_keys($str) as $key)
 			{
-				$new_array[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
+				$new_array[$this->_clean_input_keys($key)] = $this->_clean_input_data($str[$key]);
 			}
 			return $new_array;
 		}
@@ -539,7 +720,7 @@ class CI_Input {
 		}
 
 		// Standardize newlines if needed
-		if ($this->_standardize_newlines == TRUE && strpos($str, "\r") !== FALSE)
+		if ($this->_standardize_newlines === TRUE && strpos($str, "\r") !== FALSE)
 		{
 			return str_replace(array("\r\n", "\r", "\r\n\n"), PHP_EOL, $str);
 		}
@@ -550,18 +731,18 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	* Clean Keys
-	*
-	* This is a helper function. To prevent malicious users
-	* from trying to exploit keys we make sure that keys are
-	* only named with alpha-numeric text and a few other items.
-	*
-	* @param	string
-	* @return	string
-	*/
+	 * Clean Keys
+	 *
+	 * Internal method that helps to prevent malicious users
+	 * from trying to exploit keys we make sure that keys are
+	 * only named with alpha-numeric text and a few other items.
+	 *
+	 * @param	string	$str	Input string
+	 * @return	string
+	 */
 	protected function _clean_input_keys($str)
 	{
-		if ( ! preg_match('/^[a-z0-9:_\/-]+$/i', $str))
+		if ( ! preg_match('/^[a-z0-9:_\/|-]+$/i', $str))
 		{
 			set_status_header(503);
 			exit('Disallowed Key Characters.');
@@ -581,15 +762,12 @@ class CI_Input {
 	/**
 	 * Request Headers
 	 *
-	 * In Apache, you can simply call apache_request_headers(), however for
-	 * people running other webservers the function is undefined.
-	 *
-	 * @param	bool XSS cleaning
+	 * @param	bool	$xss_clean	Whether to apply XSS filtering
 	 * @return	array
 	 */
 	public function request_headers($xss_clean = FALSE)
 	{
-		// Look at Apache go!
+		// In Apache, you can simply call apache_request_headers()
 		if (function_exists('apache_request_headers'))
 		{
 			$headers = apache_request_headers();
@@ -600,9 +778,9 @@ class CI_Input {
 
 			foreach ($_SERVER as $key => $val)
 			{
-				if (strpos($key, 'HTTP_') === 0)
+				if (sscanf($key, 'HTTP_%s', $header) === 1)
 				{
-					$headers[substr($key, 5)] = $this->_fetch_from_array($_SERVER, $key, $xss_clean);
+					$headers[$header] = $this->_fetch_from_array($_SERVER, $key, $xss_clean);
 				}
 			}
 		}
@@ -626,9 +804,9 @@ class CI_Input {
 	 *
 	 * Returns the value of a single member of the headers class member
 	 *
-	 * @param	string	array key for $this->headers
-	 * @param	bool	XSS Clean or not
-	 * @return	mixed	FALSE on failure, string on success
+	 * @param	string		$index		Header name
+	 * @param	bool		$xss_clean	Whether to apply XSS filtering
+	 * @return	string|bool	The requested header on success or FALSE on failure
 	 */
 	public function get_request_header($index, $xss_clean = FALSE)
 	{
@@ -639,7 +817,7 @@ class CI_Input {
 
 		if ( ! isset($this->headers[$index]))
 		{
-			return FALSE;
+			return NULL;
 		}
 
 		return ($xss_clean === TRUE)
@@ -650,9 +828,9 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Is ajax Request?
+	 * Is AJAX request?
 	 *
-	 * Test to see if a request contains the HTTP_X_REQUESTED_WITH header
+	 * Test to see if a request contains the HTTP_X_REQUESTED_WITH header.
 	 *
 	 * @return 	bool
 	 */
@@ -664,9 +842,9 @@ class CI_Input {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Is cli Request?
+	 * Is CLI request?
 	 *
-	 * Test to see if a request was made from the command line
+	 * Test to see if a request was made from the command line.
 	 *
 	 * @return 	bool
 	 */
@@ -680,10 +858,11 @@ class CI_Input {
 	/**
 	 * Get Request Method
 	 *
-	 * Return the Request Method
+	 * Return the request method
 	 *
-	 * @param	bool	uppercase or lowercase
-	 * @return 	bool
+	 * @param	bool	$upper	Whether to return in upper or lower case
+	 *				(default: FALSE)
+	 * @return 	string
 	 */
 	public function method($upper = FALSE)
 	{
@@ -695,4 +874,4 @@ class CI_Input {
 }
 
 /* End of file Input.php */
-/* Location: ./system/core/Input.php */
+/* Location: ./system/core/Input.php */
\ No newline at end of file
diff --git a/system/core/Lang.php b/system/core/Lang.php
index 9ef76f4d6..9e6f43716 100755..100644
--- a/system/core/Lang.php
+++ b/system/core/Lang.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,8 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Language Class
@@ -41,16 +40,22 @@ class CI_Lang {
 	/**
 	 * List of translations
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $language	= array();
+	public $language =	array();
+
 	/**
 	 * List of loaded language files
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $is_loaded	= array();
+	public $is_loaded =	array();
 
+	/**
+	 * Class constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		log_message('debug', 'Language Class Initialized');
@@ -61,77 +66,90 @@ class CI_Lang {
 	/**
 	 * Load a language file
 	 *
-	 * @param	mixed	the name of the language file to be loaded. Can be an array
-	 * @param	string	the language (english, etc.)
-	 * @param	bool	return loaded array of translations
-	 * @param 	bool	add suffix to $langfile
-	 * @param 	string	alternative path to look for language file
-	 * @return	mixed
+	 * @param	mixed	$langfile	Language file name
+	 * @param	string	$idiom		Language name (english, etc.)
+	 * @param	bool	$return		Whether to return the loaded array of translations
+	 * @param 	bool	$add_suffix	Whether to add suffix to $langfile
+	 * @param 	string	$alt_path	Alternative path to look for the language file
+	 *
+	 * @return	void|string[]	Array containing translations, if $return is set to TRUE
 	 */
-	public function load($langfile = '', $idiom = '', $return = FALSE, $add_suffix = TRUE, $alt_path = '')
+	public function load($langfile, $idiom = '', $return = FALSE, $add_suffix = TRUE, $alt_path = '')
 	{
 		$langfile = str_replace('.php', '', $langfile);
 
-		if ($add_suffix == TRUE)
+		if ($add_suffix === TRUE)
 		{
-			$langfile = str_replace('_lang.', '', $langfile).'_lang';
+			$langfile = str_replace('_lang', '', $langfile).'_lang';
 		}
 
 		$langfile .= '.php';
 
-		if (in_array($langfile, $this->is_loaded, TRUE))
+		if (empty($idiom) OR ! ctype_alpha($idiom))
 		{
-			return;
+			$config =& get_config();
+			$idiom = empty($config['language']) ? 'english' : $config['language'];
 		}
 
-		$config =& get_config();
+		if ($return === FALSE && isset($this->is_loaded[$langfile]) && $this->is_loaded[$langfile] === $idiom)
+		{
+			return;
+		}
 
-		if ($idiom == '')
+		// Load the base file, so any others found can override it
+		$basepath = BASEPATH.'language/'.$idiom.'/'.$langfile;
+		if (($found = file_exists($basepath)) === TRUE)
 		{
-			$deft_lang = ( ! isset($config['language'])) ? 'english' : $config['language'];
-			$idiom = ($deft_lang == '') ? 'english' : $deft_lang;
+			include($basepath);
 		}
 
-		// Determine where the language file is and load it
-		if ($alt_path != '' && file_exists($alt_path.'language/'.$idiom.'/'.$langfile))
+		// Do we have an alternative path to look in?
+		if ($alt_path !== '')
 		{
-			include($alt_path.'language/'.$idiom.'/'.$langfile);
+			$alt_path .= 'language/'.$idiom.'/'.$langfile;
+			if (file_exists($alt_path))
+			{
+				include($alt_path);
+				$found = TRUE;
+			}
 		}
 		else
 		{
-			$found = FALSE;
-
 			foreach (get_instance()->load->get_package_paths(TRUE) as $package_path)
 			{
-				if (file_exists($package_path.'language/'.$idiom.'/'.$langfile))
+				$package_path .= 'language/'.$idiom.'/'.$langfile;
+				if ($basepath !== $package_path && file_exists($package_path))
 				{
-					include($package_path.'language/'.$idiom.'/'.$langfile);
+					include($package_path);
 					$found = TRUE;
 					break;
 				}
 			}
-
-			if ($found !== TRUE)
-			{
-				show_error('Unable to load the requested language file: language/'.$idiom.'/'.$langfile);
-			}
 		}
 
+		if ($found !== TRUE)
+		{
+			show_error('Unable to load the requested language file: language/'.$idiom.'/'.$langfile);
+		}
 
 		if ( ! isset($lang) OR ! is_array($lang))
 		{
 			log_message('error', 'Language file contains no data: language/'.$idiom.'/'.$langfile);
+
+			if ($return === TRUE)
+			{
+				return array();
+			}
 			return;
 		}
 
-		if ($return == TRUE)
+		if ($return === TRUE)
 		{
 			return $lang;
 		}
 
-		$this->is_loaded[] = $langfile;
+		$this->is_loaded[$langfile] = $idiom;
 		$this->language = array_merge($this->language, $lang);
-		unset($lang);
 
 		log_message('debug', 'Language file loaded: language/'.$idiom.'/'.$langfile);
 		return TRUE;
@@ -140,17 +158,20 @@ class CI_Lang {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch a single line of text from the language array
+	 * Language line
+	 *
+	 * Fetches a single line of text from the language array
 	 *
-	 * @param	string	$line	the language line
-	 * @return	string
+	 * @param	string	$line		Language line key
+	 * @param	bool	$log_errors	Whether to log an error message if the line is not found
+	 * @return	string	Translation
 	 */
-	public function line($line = '')
+	public function line($line = '', $log_errors = TRUE)
 	{
-		$value = ($line == '' OR ! isset($this->language[$line])) ? FALSE : $this->language[$line];
+		$value = ($line === '' OR ! isset($this->language[$line])) ? FALSE : $this->language[$line];
 
 		// Because killer robots like unicorns!
-		if ($value === FALSE)
+		if ($value === FALSE && $log_errors === TRUE)
 		{
 			log_message('error', 'Could not find the language line "'.$line.'"');
 		}
@@ -161,4 +182,4 @@ class CI_Lang {
 }
 
 /* End of file Lang.php */
-/* Location: ./system/core/Lang.php */
+/* Location: ./system/core/Lang.php */
\ No newline at end of file
diff --git a/system/core/Loader.php b/system/core/Loader.php
index 027ed20e5..651507470 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,16 +24,17 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Loader Class
  *
- * Loads views and files
+ * Loads framework components.
  *
  * @package		CodeIgniter
  * @subpackage	Libraries
- * @author		EllisLab Dev Team
  * @category	Loader
+ * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/libraries/loader.html
  */
 class CI_Loader {
@@ -42,83 +43,96 @@ class CI_Loader {
 	/**
 	 * Nesting level of the output buffering mechanism
 	 *
-	 * @var int
+	 * @var	int
 	 */
 	protected $_ci_ob_level;
+
 	/**
 	 * List of paths to load views from
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_view_paths		= array();
+	protected $_ci_view_paths =	array();
+
 	/**
 	 * List of paths to load libraries from
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_library_paths	= array();
+	protected $_ci_library_paths =	array();
+
 	/**
 	 * List of paths to load models from
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_model_paths		= array();
+	protected $_ci_model_paths =	array();
+
 	/**
 	 * List of paths to load helpers from
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_helper_paths		= array();
+	protected $_ci_helper_paths =	array();
+
 	/**
 	 * List of loaded base classes
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_base_classes		= array(); // Set by the controller class
+	protected $_base_classes =	array(); // Set by the controller class
+
 	/**
 	 * List of cached variables
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_cached_vars		= array();
+	protected $_ci_cached_vars =	array();
+
 	/**
 	 * List of loaded classes
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_classes			= array();
+	protected $_ci_classes =	array();
+
 	/**
 	 * List of loaded files
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_loaded_files		= array();
+	protected $_ci_loaded_files =	array();
+
 	/**
 	 * List of loaded models
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_models			= array();
+	protected $_ci_models =	array();
+
 	/**
 	 * List of loaded helpers
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_helpers			= array();
+	protected $_ci_helpers =	array();
+
 	/**
 	 * List of class name mappings
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_ci_varmap			= array(
-							'unit_test' => 'unit',
-							'user_agent' => 'agent'
-							);
+	protected $_ci_varmap =	array(
+		'unit_test' => 'unit',
+		'user_agent' => 'agent'
+	);
 
 	/**
-	 * Constructor
+	 * Class constructor
+	 *
+	 * Sets component load paths, gets the initial output buffering level.
 	 *
-	 * Sets the path to the view files and gets the initial output buffering level
+	 * @return	void
 	 */
 	public function __construct()
 	{
@@ -134,22 +148,18 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Initialize the Loader
+	 * Initializer
 	 *
-	 * This method is called once in CI_Controller.
-	 *
-	 * @param 	array
-	 * @return 	object
+	 * @todo	Figure out a way to move this to the constructor
+	 *		without breaking *package_path*() methods.
+	 * @uses	CI_Loader::_ci_autoloader()
+	 * @used-by	CI_Controller::__construct()
+	 * @return	void
 	 */
 	public function initialize()
 	{
-		$this->_ci_classes = array();
-		$this->_ci_loaded_files = array();
-		$this->_ci_models = array();
 		$this->_base_classes =& is_loaded();
-
 		$this->_ci_autoloader();
-		return $this;
 	}
 
 	// --------------------------------------------------------------------
@@ -157,36 +167,29 @@ class CI_Loader {
 	/**
 	 * Is Loaded
 	 *
-	 * A utility function to test if a class is in the self::$_ci_classes array.
-	 * This function returns the object name if the class tested for is loaded,
-	 * and returns FALSE if it isn't.
+	 * A utility method to test if a class is in the self::$_ci_classes array.
 	 *
-	 * It is mainly used in the form_helper -> _get_validation_object()
+	 * @used-by	Mainly used by Form Helper function _get_validation_object().
 	 *
-	 * @param 	string	class being checked for
-	 * @return 	mixed	class object name on the CI SuperObject or FALSE
+	 * @param 	string		$class	Class name to check for
+	 * @return 	string|bool	Class object name if loaded or FALSE
 	 */
 	public function is_loaded($class)
 	{
-		if (isset($this->_ci_classes[$class]))
-		{
-			return $this->_ci_classes[$class];
-		}
-
-		return FALSE;
+		return isset($this->_ci_classes[$class]) ? $this->_ci_classes[$class] : FALSE;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Class Loader
+	 * Library Loader
 	 *
-	 * This function lets users load and instantiate classes.
-	 * It is designed to be called from a user's app controllers.
+	 * Loads and instantiates libraries.
+	 * Designed to be called from application controllers.
 	 *
-	 * @param	string	the name of the class
-	 * @param	mixed	the optional parameters
-	 * @param	string	an optional object name
+	 * @param	string	$library	Library name
+	 * @param	array	$params		Optional parameters to pass to the library class constructor
+	 * @param	string	$object_name	An optional object name to assign to
 	 * @return	void
 	 */
 	public function library($library = '', $params = NULL, $object_name = NULL)
@@ -201,9 +204,9 @@ class CI_Loader {
 			return;
 		}
 
-		if ($library == '' OR isset($this->_base_classes[$library]))
+		if ($library === '' OR isset($this->_base_classes[$library]))
 		{
-			return FALSE;
+			return;
 		}
 
 		if ( ! is_null($params) && ! is_array($params))
@@ -219,26 +222,25 @@ class CI_Loader {
 	/**
 	 * Model Loader
 	 *
-	 * This function lets users load and instantiate models.
+	 * Loads and instantiates libraries.
 	 *
-	 * @param	string	the name of the class
-	 * @param	string	name for the model
-	 * @param	bool	database connection
+	 * @param	string	$model		Model name
+	 * @param	string	$name		An optional object name to assign to
+	 * @param	bool	$db_conn	An optional database connection configuration to initialize
 	 * @return	void
 	 */
 	public function model($model, $name = '', $db_conn = FALSE)
 	{
-		if (is_array($model))
+		if (empty($model))
 		{
-			foreach ($model as $babe)
-			{
-				$this->model($babe);
-			}
 			return;
 		}
-
-		if ($model == '')
+		elseif (is_array($model))
 		{
+			foreach ($model as $class)
+			{
+				$this->model($class);
+			}
 			return;
 		}
 
@@ -254,7 +256,7 @@ class CI_Loader {
 			$model = substr($model, $last_slash);
 		}
 
-		if ($name == '')
+		if (empty($name))
 		{
 			$name = $model;
 		}
@@ -311,18 +313,21 @@ class CI_Loader {
 	/**
 	 * Database Loader
 	 *
-	 * @param	string	the DB credentials
-	 * @param	bool	whether to return the DB object
-	 * @param	bool	whether to enable active record (this allows us to override the config setting)
-	 * @return	object
+	 * @param	mixed	$params		Database configuration options
+	 * @param	bool	$return 	Whether to return the database object
+	 * @param	bool	$query_builder	Whether to enable Query Builder
+	 *					(overrides the configuration setting)
+	 *
+	 * @return	void|object|bool	Database object if $return is set to TRUE,
+	 *					FALSE on failure, void in any other case
 	 */
-	public function database($params = '', $return = FALSE, $active_record = NULL)
+	public function database($params = '', $return = FALSE, $query_builder = NULL)
 	{
 		// Grab the super object
 		$CI =& get_instance();
 
 		// Do we even need to load the database class?
-		if (class_exists('CI_DB') && $return == FALSE && $active_record == NULL && isset($CI->db) && is_object($CI->db))
+		if ($return === FALSE && $query_builder === NULL && isset($CI->db) && is_object($CI->db) && ! empty($CI->db->conn_id))
 		{
 			return FALSE;
 		}
@@ -331,7 +336,7 @@ class CI_Loader {
 
 		if ($return === TRUE)
 		{
-			return DB($params, $active_record);
+			return DB($params, $query_builder);
 		}
 
 		// Initialize the db variable. Needed to prevent
@@ -339,34 +344,38 @@ class CI_Loader {
 		$CI->db = '';
 
 		// Load the DB class
-		$CI->db =& DB($params, $active_record);
+		$CI->db =& DB($params, $query_builder);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Load the Utilities Class
+	 * Load the Database Utilities Class
 	 *
-	 * @return	string
+	 * @param	object	$db	Database object
+	 * @param	bool	$return	Whether to return the DB Forge class object or not
+	 * @return	void|object
 	 */
-	public function dbutil()
+	public function dbutil($db = NULL, $return = FALSE)
 	{
-		if ( ! class_exists('CI_DB'))
-		{
-			$this->database();
-		}
-
 		$CI =& get_instance();
 
-		// for backwards compatibility, load dbforge so we can extend dbutils off it
-		// this use is deprecated and strongly discouraged
-		$CI->load->dbforge();
+		if ( ! is_object($db) OR ! ($db instanceof CI_DB))
+		{
+			class_exists('CI_DB', FALSE) OR $this->database();
+			$db =& $CI->db;
+		}
 
 		require_once(BASEPATH.'database/DB_utility.php');
-		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_utility.php');
-		$class = 'CI_DB_'.$CI->db->dbdriver.'_utility';
+		require_once(BASEPATH.'database/drivers/'.$db->dbdriver.'/'.$db->dbdriver.'_utility.php');
+		$class = 'CI_DB_'.$db->dbdriver.'_utility';
+
+		if ($return === TRUE)
+		{
+			return new $class($db);
+		}
 
-		$CI->dbutil = new $class();
+		$CI->dbutil = new $class($db);
 	}
 
 	// --------------------------------------------------------------------
@@ -374,40 +383,56 @@ class CI_Loader {
 	/**
 	 * Load the Database Forge Class
 	 *
-	 * @return	string
+	 * @param	object	$db	Database object
+	 * @param	bool	$return	Whether to return the DB Forge class object or not
+	 * @return	void|object
 	 */
-	public function dbforge()
+	public function dbforge($db = NULL, $return = FALSE)
 	{
-		if ( ! class_exists('CI_DB'))
+		$CI =& get_instance();
+		if ( ! is_object($db) OR ! ($db instanceof CI_DB))
 		{
-			$this->database();
+			class_exists('CI_DB', FALSE) OR $this->database();
+			$db =& $CI->db;
 		}
 
-		$CI =& get_instance();
-
 		require_once(BASEPATH.'database/DB_forge.php');
-		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_forge.php');
-		$class = 'CI_DB_'.$CI->db->dbdriver.'_forge';
+		require_once(BASEPATH.'database/drivers/'.$db->dbdriver.'/'.$db->dbdriver.'_forge.php');
 
-		$CI->dbforge = new $class();
+		if ( ! empty($db->subdriver))
+		{
+			$driver_path = BASEPATH.'database/drivers/'.$db->dbdriver.'/subdrivers/'.$db->dbdriver.'_'.$db->subdriver.'_forge.php';
+			if (file_exists($driver_path))
+			{
+				require_once($driver_path);
+				$class = 'CI_DB_'.$db->dbdriver.'_'.$db->subdriver.'_forge';
+			}
+		}
+		else
+		{
+			$class = 'CI_DB_'.$db->dbdriver.'_forge';
+		}
+
+		if ($return === TRUE)
+		{
+			return new $class($db);
+		}
+
+		$CI->dbforge = new $class($db);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Load View
-	 *
-	 * This function is used to load a "view" file. It has three parameters:
+	 * View 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.
+	 * Loads "view" files.
 	 *
-	 * @param	string
-	 * @param	array
-	 * @param	bool
+	 * @param	string	$view	View name
+	 * @param	array	$vars	An associative array of data
+	 *				to be extracted for use in the view
+	 * @param	bool	$return	Whether to return the view output
+	 *				or leave it to the Output class
 	 * @return	void
 	 */
 	public function view($view, $vars = array(), $return = FALSE)
@@ -418,13 +443,11 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Load File
+	 * Generic File Loader
 	 *
-	 * This is a generic file loader
-	 *
-	 * @param	string
-	 * @param	bool
-	 * @return	string
+	 * @param	string	$path	File path
+	 * @param	bool	$return	Whether to return the file output
+	 * @return	void|string
 	 */
 	public function file($path, $return = FALSE)
 	{
@@ -439,13 +462,15 @@ class CI_Loader {
 	 * Once variables are set they become available within
 	 * the controller class and its "view" files.
 	 *
-	 * @param	array
-	 * @param 	string
+	 * @param	array|object|string	$vars
+	 *					An associative array or object containing values
+	 *					to be set, or a value's name if string
+	 * @param 	string	$val	Value to set, only used if $vars is a string
 	 * @return	void
 	 */
 	public function vars($vars = array(), $val = '')
 	{
-		if ($val != '' && is_string($vars))
+		if ($val !== '' && is_string($vars))
 		{
 			$vars = array($vars => $val);
 		}
@@ -468,8 +493,8 @@ class CI_Loader {
 	 *
 	 * Check if a variable is set and retrieve it.
 	 *
-	 * @param	array
-	 * @return	void
+	 * @param	string	$key	Variable name
+	 * @return	mixed	The variable or NULL if not found
 	 */
 	public function get_var($key)
 	{
@@ -481,7 +506,7 @@ class CI_Loader {
 	/**
 	 * Get Variables
 	 *
-	 * Retrieve all loaded variables
+	 * Retrieves all loaded variables.
 	 *
 	 * @return	array
 	 */
@@ -493,11 +518,9 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Load Helper
-	 *
-	 * This function loads the specified helper file.
+	 * Helper Loader
 	 *
-	 * @param	mixed
+	 * @param	string|string[]	$helpers	Helper name(s)
 	 * @return	void
 	 */
 	public function helper($helpers = array())
@@ -509,27 +532,34 @@ class CI_Loader {
 				continue;
 			}
 
-			$ext_helper = APPPATH.'helpers/'.config_item('subclass_prefix').$helper.'.php';
-
 			// Is this a helper extension request?
-			if (file_exists($ext_helper))
+			$ext_helper = config_item('subclass_prefix').$helper;
+			$ext_loaded = FALSE;
+			foreach ($this->_ci_helper_paths as $path)
 			{
-				$base_helper = BASEPATH.'helpers/'.$helper.'.php';
+				if (file_exists($path.'helpers/'.$ext_helper.'.php'))
+				{
+					include_once($path.'helpers/'.$ext_helper.'.php');
+					$ext_loaded = TRUE;
+				}
+			}
 
+			// If we have loaded extensions - check if the base one is here
+			if ($ext_loaded === TRUE)
+			{
+				$base_helper = BASEPATH.'helpers/'.$helper.'.php';
 				if ( ! file_exists($base_helper))
 				{
 					show_error('Unable to load the requested file: helpers/'.$helper.'.php');
 				}
 
-				include_once($ext_helper);
 				include_once($base_helper);
-
 				$this->_ci_helpers[$helper] = TRUE;
 				log_message('debug', 'Helper loaded: '.$helper);
 				continue;
 			}
 
-			// Try to load the helper
+			// No extensions found ... try loading regular helpers and/or overrides
 			foreach ($this->_ci_helper_paths as $path)
 			{
 				if (file_exists($path.'helpers/'.$helper.'.php'))
@@ -555,10 +585,11 @@ class CI_Loader {
 	/**
 	 * Load Helpers
 	 *
-	 * This is simply an alias to the above function in case the
-	 * user has written the plural form of this function.
+	 * An alias for the helper() method in case the developer has
+	 * written the plural form of it.
 	 *
-	 * @param	array
+	 * @uses	CI_Loader::helper()
+	 * @param	string|string[]	$helpers	Helper name(s)
 	 * @return	void
 	 */
 	public function helpers($helpers = array())
@@ -569,22 +600,21 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Loads a language file
+	 * Language Loader
 	 *
-	 * @param	array
-	 * @param	string
+	 * Loads language files.
+	 *
+	 * @param	string|string[]	$files	List of language file names to load
+	 * @param	string		Language name
 	 * @return	void
 	 */
-	public function language($file = array(), $lang = '')
+	public function language($files = array(), $lang = '')
 	{
 		$CI =& get_instance();
 
-		if ( ! is_array($file))
-		{
-			$file = array($file);
-		}
+		is_array($files) OR $files = array($files);
 
-		foreach ($file as $langfile)
+		foreach ($files as $langfile)
 		{
 			$CI->lang->load($langfile, $lang);
 		}
@@ -593,30 +623,35 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Loads a config file
+	 * Config Loader
 	 *
-	 * @param	string
-	 * @param	bool
-	 * @param 	bool
-	 * @return	void
+	 * Loads a config file (an alias for CI_Config::load()).
+	 *
+	 * @uses	CI_Config::load()
+	 * @param	string	$file			Configuration file name
+	 * @param	bool	$use_sections		Whether configuration values should be loaded into their own section
+	 * @param	bool	$fail_gracefully	Whether to just return FALSE or display an error message
+	 * @return	bool	TRUE if the file was loaded correctly or FALSE on failure
 	 */
 	public function config($file = '', $use_sections = FALSE, $fail_gracefully = FALSE)
 	{
 		$CI =& get_instance();
-		$CI->config->load($file, $use_sections, $fail_gracefully);
+		return $CI->config->load($file, $use_sections, $fail_gracefully);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Driver
+	 * Driver Loader
 	 *
-	 * Loads a driver library
+	 * Loads a driver library.
 	 *
-	 * @param	mixed	the name of the class or array of classes
-	 * @param	mixed	the optional parameters
-	 * @param	string	an optional object name
-	 * @return	void
+	 * @param	string|string[]	$library	Driver name(s)
+	 * @param	array		$params		Optional parameters to pass to the driver
+	 * @param	string		$object_name	An optional object name to assign to
+	 *
+	 * @return	void|object|bool	Object or FALSE on failure if $library is a string
+	 *					and $object_name is set. void otherwise.
 	 */
 	public function driver($library = '', $params = NULL, $object_name = NULL)
 	{
@@ -626,18 +661,18 @@ class CI_Loader {
 			{
 				$this->driver($driver);
 			}
-			return FALSE;
+			return;
 		}
 
-		if ( ! class_exists('CI_Driver_Library'))
+		if ($library === '')
 		{
-			// we aren't instantiating an object here, that'll be done by the Library itself
-			require BASEPATH.'libraries/Driver.php';
+			return FALSE;
 		}
 
-		if ($library == '')
+		if ( ! class_exists('CI_Driver_Library'))
 		{
-			return FALSE;
+			// We aren't instantiating an object here, just making the base class available
+			require BASEPATH.'libraries/Driver.php';
 		}
 
 		// We can save the loader some time since Drivers will *always* be in a subfolder,
@@ -655,13 +690,19 @@ class CI_Loader {
 	/**
 	 * Add Package Path
 	 *
-	 * Prepends a parent path to the library, model, helper, and config path arrays
+	 * Prepends a parent path to the library, model, helper and config
+	 * path arrays.
 	 *
-	 * @param	string
-	 * @param 	bool
+	 * @see	CI_Loader::$_ci_library_paths
+	 * @see	CI_Loader::$_ci_model_paths
+	 * @see CI_Loader::$_ci_helper_paths
+	 * @see CI_Config::$_config_paths
+	 *
+	 * @param	string	$path		Path to add
+	 * @param 	bool	$view_cascade	(default: TRUE)
 	 * @return	void
 	 */
-	public function add_package_path($path, $view_cascade=TRUE)
+	public function add_package_path($path, $view_cascade = TRUE)
 	{
 		$path = rtrim($path, '/').'/';
 
@@ -673,7 +714,7 @@ class CI_Loader {
 
 		// Add config file path
 		$config =& $this->_ci_get_component('config');
-		array_unshift($config->_config_paths, $path);
+		array_push($config->_config_paths, $path);
 	}
 
 	// --------------------------------------------------------------------
@@ -681,14 +722,14 @@ class CI_Loader {
 	/**
 	 * Get Package Paths
 	 *
-	 * Return a list of all package paths, by default it will ignore BASEPATH.
+	 * Return a list of all package paths.
 	 *
-	 * @param	string
-	 * @return	void
+	 * @param	bool	$include_base	Whether to include BASEPATH (default: TRUE)
+	 * @return	array
 	 */
 	public function get_package_paths($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;
 	}
 
 	// --------------------------------------------------------------------
@@ -696,24 +737,24 @@ class CI_Loader {
 	/**
 	 * Remove Package Path
 	 *
-	 * Remove a path from the library, model, and helper path arrays if it exists
-	 * If no path is provided, the most recently added path is removed.
+	 * Remove a path from the library, model, helper and/or config
+	 * path arrays if it exists. If no path is provided, the most recently
+	 * added path will be removed removed.
 	 *
-	 * @param	string
-	 * @param 	bool
+	 * @param	string	$path	Path to remove
 	 * @return	void
 	 */
-	public function remove_package_path($path = '', $remove_config_path = TRUE)
+	public function remove_package_path($path = '')
 	{
 		$config =& $this->_ci_get_component('config');
 
-		if ($path == '')
+		if ($path === '')
 		{
 			array_shift($this->_ci_library_paths);
 			array_shift($this->_ci_model_paths);
 			array_shift($this->_ci_helper_paths);
 			array_shift($this->_ci_view_paths);
-			array_shift($config->_config_paths);
+			array_pop($config->_config_paths);
 		}
 		else
 		{
@@ -748,13 +789,16 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Loader
+	 * Internal CI Data Loader
+	 *
+	 * Used to load views and files.
 	 *
-	 * This function is used to load views and files.
 	 * Variables are prefixed with _ci_ to avoid symbol collision with
-	 * variables made available to view files
+	 * variables made available to view files.
 	 *
-	 * @param	array
+	 * @used-by	CI_Loader::view()
+	 * @used-by	CI_Loader::file()
+	 * @param	array	$_ci_data	Data to load
 	 * @return	void
 	 */
 	protected function _ci_load($_ci_data)
@@ -768,7 +812,7 @@ class CI_Loader {
 		$file_exists = FALSE;
 
 		// Set the path to the requested file
-		if ($_ci_path != '')
+		if (is_string($_ci_path) && $_ci_path !== '')
 		{
 			$_ci_x = explode('/', $_ci_path);
 			$_ci_file = end($_ci_x);
@@ -776,13 +820,13 @@ class CI_Loader {
 		else
 		{
 			$_ci_ext = pathinfo($_ci_view, PATHINFO_EXTENSION);
-			$_ci_file = ($_ci_ext == '') ? $_ci_view.'.php' : $_ci_view;
+			$_ci_file = ($_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;
 				}
@@ -813,7 +857,7 @@ class CI_Loader {
 		/*
 		 * Extract and cache variables
 		 *
-		 * You can either set variables using the dedicated $this->load_vars()
+		 * You can either set variables using the dedicated $this->load->vars()
 		 * function or via the second parameter of this function. We'll merge
 		 * the two types and cache them so that views that are embedded within
 		 * other views can have access to these variables.
@@ -830,17 +874,19 @@ 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();
 
 		// If the PHP installation does not support short tags we'll
 		// do a little string replacement, changing the short tags
 		// to standard PHP echo statements.
-		if ( ! is_php('5.4') && (bool) @ini_get('short_open_tag') === FALSE && config_item('rewrite_short_tags') == TRUE)
+		if ( ! is_php('5.4') && (bool) @ini_get('short_open_tag') === FALSE
+			&& config_item('rewrite_short_tags') === TRUE && function_usable('eval')
+		)
 		{
 			echo eval('?>'.preg_replace('/;*\s*\?>/', '; ?>', str_replace('<?=', '<?php echo ', file_get_contents($_ci_path))));
 		}
@@ -882,13 +928,14 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Load class
+	 * Internal CI Class Loader
 	 *
-	 * This function loads the requested class.
+	 * @used-by	CI_Loader::library()
+	 * @uses	CI_Loader::_ci_init_class()
 	 *
-	 * @param	string	the item that is being loaded
-	 * @param	mixed	any additional parameters
-	 * @param	string	an optional object name
+	 * @param	string	$class		Class name to load
+	 * @param	mixed	$params		Optional parameters to pass to the class constructor
+	 * @param	string	$object_name	Optional object name to assign to
 	 * @return	void
 	 */
 	protected function _ci_load_class($class, $params = NULL, $object_name = NULL)
@@ -989,19 +1036,24 @@ 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 ($subdir == '')
+		if ($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.
 		// We do not issue errors if the load call failed due to a duplicate request
-		if ($is_duplicate == FALSE)
+		if ($is_duplicate === FALSE)
 		{
 			log_message('error', 'Unable to load the requested class: '.$class);
 			show_error('Unable to load the requested class: '.$class);
@@ -1011,12 +1063,17 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Instantiates a class
+	 * Internal CI Class Instantiator
+	 *
+	 * @used-by	CI_Loader::_ci_load_class()
 	 *
-	 * @param	string
-	 * @param	string
-	 * @param	bool
-	 * @param	string	an optional object name
+	 * @param	string		$class		Class name
+	 * @param	string		$prefix		Class name prefix
+	 * @param	array|null|bool	$config		Optional configuration to pass to the class constructor:
+	 *						FALSE to skip;
+	 *						NULL to search in config paths;
+	 *						array containing configuration data
+	 * @param	string		$object_name	Optional object name to assign to
 	 * @return	void
 	 */
 	protected function _ci_init_class($class, $prefix = '', $config = FALSE, $object_name = NULL)
@@ -1060,7 +1117,7 @@ class CI_Loader {
 			}
 		}
 
-		if ($prefix == '')
+		if ($prefix === '')
 		{
 			if (class_exists('CI_'.$class))
 			{
@@ -1084,7 +1141,7 @@ class CI_Loader {
 		if ( ! class_exists($name))
 		{
 			log_message('error', 'Non-existent class: '.$name);
-			show_error('Non-existent class: '.$class);
+			show_error('Non-existent class: '.$name);
 		}
 
 		// Set the variable name we will assign the class to
@@ -1118,12 +1175,11 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Autoloader
+	 * CI Autoloader
 	 *
-	 * The config/autoload.php file contains an array that permits sub-systems,
-	 * libraries, and helpers to be loaded automatically.
+	 * Loads component listed in the config/autoload.php file.
 	 *
-	 * @param	array
+	 * @used-by	CI_Loader::initialize()
 	 * @return	void
 	 */
 	protected function _ci_autoloader()
@@ -1187,6 +1243,15 @@ class CI_Loader {
 			}
 		}
 
+		// Autoload drivers
+		if (isset($autoload['drivers']))
+		{
+			foreach ($autoload['drivers'] as $item)
+			{
+				$this->driver($item);
+			}
+		}
+
 		// Autoload models
 		if (isset($autoload['model']))
 		{
@@ -1197,11 +1262,12 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Object to Array
+	 * CI Object to Array translator
 	 *
-	 * Takes an object as input and converts the class variables to array key/vals
+	 * Takes an object as input and converts the class variables to
+	 * an associative array with key/value pairs.
 	 *
-	 * @param	object
+	 * @param	object	$object	Object data to translate
 	 * @return	array
 	 */
 	protected function _ci_object_to_array($object)
@@ -1212,9 +1278,11 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Get a reference to a specific library or model
+	 * CI Component getter
+	 *
+	 * Get a reference to a specific library or model.
 	 *
-	 * @param 	string
+	 * @param 	string	$component	Component name
 	 * @return	bool
 	 */
 	protected function &_ci_get_component($component)
@@ -1228,10 +1296,11 @@ class CI_Loader {
 	/**
 	 * Prep filename
 	 *
-	 * This function preps the name of various items to make loading them more reliable.
+	 * This function prepares filenames of various items to
+	 * make their loading more reliable.
 	 *
-	 * @param	mixed
-	 * @param 	string
+	 * @param	string|string[]	$filename	Filename(s)
+	 * @param 	string		$extension	Filename extension
 	 * @return	array
 	 */
 	protected function _ci_prep_filename($filename, $extension)
diff --git a/system/core/Log.php b/system/core/Log.php
new file mode 100644
index 000000000..718f50587
--- /dev/null
+++ b/system/core/Log.php
@@ -0,0 +1,180 @@
+<?php
+/**
+ * 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
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * Logging Class
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Logging
+ * @author		EllisLab Dev Team
+ * @link		http://codeigniter.com/user_guide/general/errors.html
+ */
+class CI_Log {
+
+	/**
+	 * Path to save log files
+	 *
+	 * @var string
+	 */
+	protected $_log_path;
+
+	/**
+	 * Level of logging
+	 *
+	 * @var int
+	 */
+	protected $_threshold		= 1;
+
+	/**
+	 * Highest level of logging
+	 *
+	 * @var int
+	 */
+	protected $_threshold_max	= 0;
+
+	/**
+	 * Array of threshold levels to log
+	 *
+	 * @var array
+	 */
+	protected $_threshold_array	= array();
+
+	/**
+	 * Format of timestamp for log files
+	 *
+	 * @var string
+	 */
+	protected $_date_fmt		= 'Y-m-d H:i:s';
+
+	/**
+	 * Whether or not the logger can write to the log files
+	 *
+	 * @var bool
+	 */
+	protected $_enabled		= TRUE;
+
+	/**
+	 * Predefined logging levels
+	 *
+	 * @var array
+	 */
+	protected $_levels		= array('ERROR' => 1, 'DEBUG' => 2, 'INFO' => 3, 'ALL' => 4);
+
+	/**
+	 * Initialize Logging class
+	 *
+	 * @return	void
+	 */
+	public function __construct()
+	{
+		$config =& get_config();
+
+		$this->_log_path = ($config['log_path'] !== '') ? $config['log_path'] : APPPATH.'logs/';
+
+		if ( ! is_dir($this->_log_path) OR ! is_really_writable($this->_log_path))
+		{
+			$this->_enabled = FALSE;
+		}
+
+		if (is_numeric($config['log_threshold']))
+		{
+			$this->_threshold = (int) $config['log_threshold'];
+		}
+		elseif (is_array($config['log_threshold']))
+		{
+			$this->_threshold = $this->_threshold_max;
+			$this->_threshold_array = array_flip($config['log_threshold']);
+		}
+
+		if ($config['log_date_format'] !== '')
+		{
+			$this->_date_fmt = $config['log_date_format'];
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Write Log File
+	 *
+	 * Generally this function will be called using the global log_message() function
+	 *
+	 * @param	string	the error level
+	 * @param	string	the error message
+	 * @param	bool	whether the error is a native PHP error
+	 * @return	bool
+	 */
+	public function write_log($level = 'error', $msg, $php_error = FALSE)
+	{
+		if ($this->_enabled === FALSE)
+		{
+			return FALSE;
+		}
+
+		$level = strtoupper($level);
+
+		if (( ! isset($this->_levels[$level]) OR ($this->_levels[$level] > $this->_threshold))
+			&& ! isset($this->_threshold_array[$this->_levels[$level]]))
+		{
+			return FALSE;
+		}
+
+		$filepath = $this->_log_path.'log-'.date('Y-m-d').'.php';
+		$message  = '';
+
+		if ( ! file_exists($filepath))
+		{
+			$newfile = TRUE;
+			$message .= '<'."?php defined('BASEPATH') OR exit('No direct script access allowed'); ?".">\n\n";
+		}
+
+		if ( ! $fp = @fopen($filepath, FOPEN_WRITE_CREATE))
+		{
+			return FALSE;
+		}
+
+		$message .= $level.' '.($level === 'INFO' ? ' -' : '-').' '.date($this->_date_fmt).' --> '.$msg."\n";
+
+		flock($fp, LOCK_EX);
+		fwrite($fp, $message);
+		flock($fp, LOCK_UN);
+		fclose($fp);
+
+		if (isset($newfile) && $newfile === TRUE)
+		{
+			@chmod($filepath, FILE_WRITE_MODE);
+		}
+
+		return TRUE;
+	}
+
+}
+
+/* End of file Log.php */
+/* Location: ./system/libraries/Log.php */
\ No newline at end of file
diff --git a/system/core/Model.php b/system/core/Model.php
index 49b8d34e4..28fdfbb69 100755..100644
--- a/system/core/Model.php
+++ b/system/core/Model.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,11 +24,10 @@
  * @since		Version 1.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
- * CodeIgniter Model Class
+ * Model Class
  *
  * @package		CodeIgniter
  * @subpackage	Libraries
@@ -38,25 +37,33 @@
  */
 class CI_Model {
 
+	/**
+	 * Class constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		log_message('debug', 'Model Class Initialized');
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * __get
+	 * __get magic
 	 *
 	 * Allows models to access CI's loaded classes using the same
 	 * syntax as controllers.
 	 *
-	 * @param	string
+	 * @param	string	$key
 	 */
 	public function __get($key)
 	{
 		$CI =& get_instance();
 		return $CI->$key;
 	}
+
 }
 
 /* End of file Model.php */
-/* Location: ./system/core/Model.php */
+/* Location: ./system/core/Model.php */
\ No newline at end of file
diff --git a/system/core/Output.php b/system/core/Output.php
index 3cb40626a..98deff55c 100755..100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,11 +24,12 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Output Class
  *
- * Responsible for sending final output to browser
+ * Responsible for sending final output to the browser.
  *
  * @package		CodeIgniter
  * @subpackage	Libraries
@@ -39,70 +40,84 @@
 class CI_Output {
 
 	/**
-	 * Current output string
+	 * Final output string
 	 *
-	 * @var string
+	 * @var	string
 	 */
 	public $final_output;
+
 	/**
 	 * Cache expiration time
 	 *
-	 * @var int
+	 * @var	int
 	 */
-	public $cache_expiration	= 0;
+	public $cache_expiration = 0;
+
 	/**
 	 * List of server headers
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $headers			= array();
+	public $headers =	array();
+
 	/**
 	 * List of mime types
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $mime_types		= array();
+	public $mimes =		array();
+
 	/**
-	 * Determines wether profiler is enabled
+	 * Mime-type for the current page
 	 *
-	 * @var book
+	 * @var	string
 	 */
-	public $enable_profiler		= FALSE;
+	protected $mime_type	= 'text/html';
+
 	/**
-	 * Determines if output compression is enabled
+	 * Enable Profiler flag
 	 *
-	 * @var bool
+	 * @var	bool
 	 */
-	protected $_zlib_oc		= FALSE;
+	public $enable_profiler = FALSE;
+
+	/**
+	 * zLib output compression flag
+	 *
+	 * @var	bool
+	 */
+	protected $_zlib_oc =		FALSE;
+
 	/**
 	 * List of profiler sections
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_profiler_sections = array();
+	protected $_profiler_sections =	array();
+
 	/**
-	 * Whether or not to parse variables like {elapsed_time} and {memory_usage}
+	 * Parse markers flag
 	 *
-	 * @var bool
+	 * Whether or not to parse variables like {elapsed_time} and {memory_usage}.
+	 *
+	 * @var	bool
 	 */
-	public $parse_exec_vars		= TRUE;
+	public $parse_exec_vars =	TRUE;
 
+	/**
+	 * Class constructor
+	 *
+	 * Determines whether zLib output compression will be used.
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
-		$this->_zlib_oc = @ini_get('zlib.output_compression');
+		$this->_zlib_oc = (bool) @ini_get('zlib.output_compression');
 
 		// Get mime types for later
-		if (defined('ENVIRONMENT') && file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
-		{
-			include APPPATH.'config/'.ENVIRONMENT.'/mimes.php';
-		}
-		else
-		{
-			include APPPATH.'config/mimes.php';
-		}
-
+		$this->mimes =& get_mimes();
 
-		$this->mime_types = $mimes;
 		log_message('debug', 'Output Class Initialized');
 	}
 
@@ -111,7 +126,7 @@ class CI_Output {
 	/**
 	 * Get Output
 	 *
-	 * Returns the current output string
+	 * Returns the current output string.
 	 *
 	 * @return	string
 	 */
@@ -125,10 +140,10 @@ class CI_Output {
 	/**
 	 * Set Output
 	 *
-	 * Sets the output string
+	 * Sets the output string.
 	 *
-	 * @param	string
-	 * @return	void
+	 * @param	string	$output	Output data
+	 * @return	object	$this
 	 */
 	public function set_output($output)
 	{
@@ -141,14 +156,14 @@ class CI_Output {
 	/**
 	 * Append Output
 	 *
-	 * Appends data onto the output string
+	 * Appends data onto the output string.
 	 *
-	 * @param	string
-	 * @return	void
+	 * @param	string	$output	Data to append
+	 * @return	object	$this
 	 */
 	public function append_output($output)
 	{
-		if ($this->final_output == '')
+		if (empty($this->final_output))
 		{
 			$this->final_output = $output;
 		}
@@ -165,14 +180,14 @@ class CI_Output {
 	/**
 	 * Set Header
 	 *
-	 * Lets you set a server header which will be outputted with the final display.
+	 * Lets you set a server header which will be sent with the final output.
 	 *
-	 * Note:  If a file is cached, headers will not be sent.  We need to figure out
-	 * how to permit header data to be saved with the cache data...
+	 * Note: If a file is cached, headers will not be sent.
+	 * @todo	We need to figure out how to permit headers to be cached.
 	 *
-	 * @param	string
-	 * @param 	bool
-	 * @return	void
+	 * @param	string	$header		Header
+	 * @param	bool	$replace	Whether to replace the old header value, if already set
+	 * @return	object	$this
 	 */
 	public function set_header($header, $replace = TRUE)
 	{
@@ -180,9 +195,9 @@ class CI_Output {
 		// but it will not modify the content-length header to compensate for
 		// the reduction, causing the browser to hang waiting for more data.
 		// We'll just skip content-length in those cases.
-		if ($this->_zlib_oc && strncasecmp($header, 'content-length', 14) == 0)
+		if ($this->_zlib_oc && strncasecmp($header, 'content-length', 14) === 0)
 		{
-			return;
+			return $this;
 		}
 
 		$this->headers[] = array($header, $replace);
@@ -192,21 +207,22 @@ class CI_Output {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set Content Type Header
+	 * Set Content-Type Header
 	 *
-	 * @param	string	extension of the file we're outputting
-	 * @return	void
+	 * @param	string	$mime_type	Extension of the file we're outputting
+	 * @param	string	$charset	Character set (default: NULL)
+	 * @return	object	$this
 	 */
-	public function set_content_type($mime_type)
+	public function set_content_type($mime_type, $charset = NULL)
 	{
 		if (strpos($mime_type, '/') === FALSE)
 		{
 			$extension = ltrim($mime_type, '.');
 
 			// Is this extension supported?
-			if (isset($this->mime_types[$extension]))
+			if (isset($this->mimes[$extension]))
 			{
-				$mime_type =& $this->mime_types[$extension];
+				$mime_type =& $this->mimes[$extension];
 
 				if (is_array($mime_type))
 				{
@@ -215,7 +231,15 @@ class CI_Output {
 			}
 		}
 
-		$header = 'Content-Type: '.$mime_type;
+		$this->mime_type = $mime_type;
+
+		if (empty($charset))
+		{
+			$charset = config_item('charset');
+		}
+
+		$header = 'Content-Type: '.$mime_type
+			.(empty($charset) ? NULL : '; charset='.strtolower($charset));
 
 		$this->headers[] = array($header, TRUE);
 		return $this;
@@ -224,7 +248,7 @@ class CI_Output {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Get Current Content Type Header
+	 * Get Current Content-Type Header
 	 *
 	 * @return	string	'text/html', if not already set
 	 */
@@ -232,9 +256,9 @@ class CI_Output {
 	{
 		for ($i = 0, $c = count($this->headers); $i < $c; $i++)
 		{
-			if (preg_match('/^Content-Type:\s(.+)$/', $this->headers[$i][0], $matches))
+			if (sscanf($this->headers[$i][0], 'Content-Type: %[^;]', $content_type) === 1)
 			{
-				return $matches[1];
+				return $content_type;
 			}
 		}
 
@@ -244,12 +268,47 @@ class CI_Output {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Get Header
+	 *
+	 * @param	string	$header_name
+	 * @return	string
+	 */
+	public function get_header($header)
+	{
+		// Combine headers already sent with our batched headers
+		$headers = array_merge(
+			// We only need [x][0] from our multi-dimensional array
+			array_map('array_shift', $this->headers),
+			headers_list()
+		);
+
+		if (empty($headers) OR empty($header))
+		{
+			return NULL;
+		}
+
+		for ($i = 0, $c = count($headers); $i < $c; $i++)
+		{
+			if (strncasecmp($header, $headers[$i], $l = strlen($header)) === 0)
+			{
+				return trim(substr($headers[$i], $l+1));
+			}
+		}
+
+		return NULL;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Set HTTP Status Header
-	 * moved to Common procedural functions in 1.7.2
 	 *
-	 * @param	int	the status code
-	 * @param	string
-	 * @return	void
+	 * As of version 1.7.2, this is an alias for common function
+	 * set_status_header().
+	 *
+	 * @param	int	$code	Status code (default: 200)
+	 * @param	string	$text	Optional message
+	 * @return	object	$this
 	 */
 	public function set_status_header($code = 200, $text = '')
 	{
@@ -262,8 +321,8 @@ class CI_Output {
 	/**
 	 * Enable/disable Profiler
 	 *
-	 * @param	bool
-	 * @return	void
+	 * @param	bool	$val	TRUE to enable or FALSE to disable
+	 * @return	object	$this
 	 */
 	public function enable_profiler($val = TRUE)
 	{
@@ -276,13 +335,20 @@ class CI_Output {
 	/**
 	 * Set Profiler Sections
 	 *
-	 * Allows override of default / config settings for Profiler section display
+	 * Allows override of default/config settings for
+	 * Profiler section display.
 	 *
-	 * @param	array
-	 * @return	void
+	 * @param	array	$sections	Profiler sections
+	 * @return	object	$this
 	 */
 	public function set_profiler_sections($sections)
 	{
+		if (isset($sections['query_toggle_count']))
+		{
+			$this->_profiler_sections['query_toggle_count'] = (int) $sections['query_toggle_count'];
+			unset($sections['query_toggle_count']);
+		}
+
 		foreach ($sections as $section => $enable)
 		{
 			$this->_profiler_sections[$section] = ($enable !== FALSE);
@@ -296,8 +362,8 @@ class CI_Output {
 	/**
 	 * Set Cache
 	 *
-	 * @param	int
-	 * @return	void
+	 * @param	int	$time	Cache expiration time in seconds
+	 * @return	object	$this
 	 */
 	public function cache($time)
 	{
@@ -310,16 +376,16 @@ class CI_Output {
 	/**
 	 * Display Output
 	 *
-	 * All "view" data is automatically put into this variable by the controller class:
-	 *
-	 * $this->final_output
+	 * Processes sends the sends finalized output data to the browser along
+	 * with any server headers and profile data. It also stops benchmark
+	 * timers so the page rendering speed and memory usage can be shown.
 	 *
-	 * This function sends the finalized output data to the browser along
-	 * with any server headers and profile data. It also stops the
-	 * benchmark timer so the page rendering speed and memory usage can be shown.
+	 * Note: All "view" data is automatically put into $this->final_output
+	 *	 by controller class.
 	 *
-	 * @param 	string
-	 * @return	mixed
+	 * @uses	CI_Output::$final_output
+	 * @param	string	$output	Output data override
+	 * @return	void
 	 */
 	public function _display($output = '')
 	{
@@ -337,14 +403,22 @@ class CI_Output {
 		// --------------------------------------------------------------------
 
 		// Set the output data
-		if ($output == '')
+		if ($output === '')
 		{
 			$output =& $this->final_output;
 		}
 
 		// --------------------------------------------------------------------
 
-		// Do we need to write a cache file?  Only if the controller does not have its
+		// Is minify requested?
+		if ($CFG->item('minify_output') === TRUE)
+		{
+			$output = $this->minify($output, $this->mime_type);
+		}
+
+		// --------------------------------------------------------------------
+
+		// Do we need to write a cache file? Only if the controller does not have its
 		// own _output() method and we are not dealing with a cache file, which we
 		// can determine by the existence of the $CI object above
 		if ($this->cache_expiration > 0 && isset($CI) && ! method_exists($CI, '_output'))
@@ -361,7 +435,7 @@ class CI_Output {
 
 		if ($this->parse_exec_vars === TRUE)
 		{
-			$memory	= function_exists('memory_get_usage') ? round(memory_get_usage()/1024/1024, 2).'MB' : '0';
+			$memory	= round(memory_get_usage() / 1024 / 1024, 2).'MB';
 
 			$output = str_replace(array('{elapsed_time}', '{memory_usage}'), array($elapsed, $memory), $output);
 		}
@@ -369,7 +443,7 @@ class CI_Output {
 		// --------------------------------------------------------------------
 
 		// Is compression requested?
-		if ($CFG->item('compress_output') === TRUE && $this->_zlib_oc == FALSE
+		if ($CFG->item('compress_output') === TRUE && $this->_zlib_oc === FALSE
 			&& extension_loaded('zlib')
 			&& isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE)
 		{
@@ -397,14 +471,14 @@ class CI_Output {
 			echo $output;
 			log_message('debug', 'Final output sent to browser');
 			log_message('debug', 'Total execution time: '.$elapsed);
-			return TRUE;
+			return;
 		}
 
 		// --------------------------------------------------------------------
 
 		// Do we need to generate profile data?
 		// If so, load the Profile class and run it.
-		if ($this->enable_profiler == TRUE)
+		if ($this->enable_profiler === TRUE)
 		{
 			$CI->load->library('profiler');
 			if ( ! empty($this->_profiler_sections))
@@ -439,16 +513,16 @@ class CI_Output {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Write a Cache File
+	 * Write Cache
 	 *
-	 * @param 	string
+	 * @param	string	$output	Output data to cache
 	 * @return	void
 	 */
 	public function _write_cache($output)
 	{
 		$CI =& get_instance();
 		$path = $CI->config->item('cache_path');
-		$cache_path = ($path == '') ? APPPATH.'cache/' : $path;
+		$cache_path = ($path === '') ? APPPATH.'cache/' : $path;
 
 		if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
 		{
@@ -484,20 +558,26 @@ class CI_Output {
 		@chmod($cache_path, FILE_WRITE_MODE);
 
 		log_message('debug', 'Cache file written: '.$cache_path);
+
+		// Send HTTP cache-control headers to browser to match file cache settings.
+		$this->set_cache_header($_SERVER['REQUEST_TIME'], $expire);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update/serve a cached file
+	 * Update/serve cached output
 	 *
-	 * @param 	object	config class
-	 * @param 	object	uri class
-	 * @return	void
+	 * @uses	CI_Config
+	 * @uses	CI_URI
+	 *
+	 * @param	object	&$CFG	CI_Config class instance
+	 * @param	object	&$URI	CI_URI class instance
+	 * @return	bool	TRUE on success or FALSE on failure
 	 */
 	public function _display_cache(&$CFG, &$URI)
 	{
-		$cache_path = ($CFG->item('cache_path') == '') ? APPPATH.'cache/' : $CFG->item('cache_path');
+		$cache_path = ($CFG->item('cache_path') === '') ? APPPATH.'cache/' : $CFG->item('cache_path');
 
 		// Build the file path. The file name is an MD5 hash of the full URI
 		$uri =	$CFG->item('base_url').$CFG->item('index_page').$URI->uri_string;
@@ -516,25 +596,211 @@ class CI_Output {
 		fclose($fp);
 
 		// Strip out the embedded timestamp
-		if ( ! preg_match('/(\d+TS--->)/', $cache, $match))
+		if ( ! preg_match('/^(\d+)TS--->/', $cache, $match))
 		{
 			return FALSE;
 		}
 
-		// Has the file expired? If so we'll delete it.
-		if (time() >= trim(str_replace('TS--->', '', $match[1])) && is_really_writable($cache_path))
+		$last_modified = filemtime($cache_path);
+		$expire = $match[1];
+
+		// Has the file expired?
+		if ($_SERVER['REQUEST_TIME'] >= $expire && is_really_writable($cache_path))
 		{
+			// If so we'll delete it.
 			@unlink($filepath);
 			log_message('debug', 'Cache file has expired. File deleted.');
 			return FALSE;
 		}
+		else
+		{
+			// Or else send the HTTP cache control headers.
+			$this->set_cache_header($last_modified, $expire);
+		}
 
 		// 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;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete cache
+	 *
+	 * @param	string	$uri	URI string
+	 * @return	bool
+	 */
+	public function delete_cache($uri = '')
+	{
+		$CI =& get_instance();
+		$cache_path = $CI->config->item('cache_path');
+		if ($cache_path === '')
+		{
+			$cache_path = APPPATH.'cache/';
+		}
+
+		if ( ! is_dir($cache_path))
+		{
+			log_message('error', 'Unable to find cache path: '.$cache_path);
+			return FALSE;
+		}
+
+		if (empty($uri))
+		{
+			$uri = $CI->uri->uri_string();
+		}
+
+		$cache_path .= md5($CI->config->item('base_url').$CI->config->item('index_page').$uri);
+
+		if ( ! @unlink($cache_path))
+		{
+			log_message('error', 'Unable to delete cache file for '.$uri);
+			return FALSE;
+		}
+
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set Cache Header
+	 *
+	 * Set the HTTP headers to match the server-side file cache settings
+	 * in order to reduce bandwidth.
+	 *
+	 * @param	int	$last_modified	Timestamp of when the page was last modified
+	 * @param	int	$expiration	Timestamp of when should the requested page expire from cache
+	 * @return	void
+	 */
+	public function set_cache_header($last_modified, $expiration)
+	{
+		$max_age = $expiration - $_SERVER['REQUEST_TIME'];
+
+		if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && $last_modified <= strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']))
+		{
+			$this->set_status_header(304);
+			exit;
+		}
+		else
+		{
+			header('Pragma: public');
+			header('Cache-Control: max-age=' . $max_age . ', public');
+			header('Expires: '.gmdate('D, d M Y H:i:s', $expiration).' GMT');
+			header('Last-modified: '.gmdate('D, d M Y H:i:s', $last_modified).' GMT');
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Minify
+	 *
+	 * Reduce excessive size of HTML/CSS/JavaScript content.
+	 *
+	 * @param	string	$output	Output to minify
+	 * @param	string	$type	Output content MIME type
+	 * @return	string	Minified output
+	 */
+	public function minify($output, $type = 'text/html')
+	{
+		switch ($type)
+		{
+			case 'text/html':
+
+				$size_before = strlen($output);
+
+				if ($size_before === 0)
+				{
+					return '';
+				}
+
+				// Find all the <pre>,<code>,<textarea>, and <javascript> tags
+				// We'll want to return them to this unprocessed state later.
+				preg_match_all('{<pre.+</pre>}msU', $output, $pres_clean);
+				preg_match_all('{<code.+</code>}msU', $output, $codes_clean);
+				preg_match_all('{<textarea.+</textarea>}msU', $output, $textareas_clean);
+				preg_match_all('{<script.+</script>}msU', $output, $javascript_clean);
+
+				// Minify the CSS in all the <style> tags.
+				preg_match_all('{<style.+</style>}msU', $output, $style_clean);
+				foreach ($style_clean[0] as $s)
+				{
+					$output = str_replace($s, $this->minify($s, 'text/css'), $output);
+				}
+
+				// Minify the javascript in <script> tags.
+				foreach ($javascript_clean[0] as $s)
+				{
+					$javascript_mini[] = $this->minify($s, 'text/javascript');
+				}
+
+				// Replace multiple spaces with a single space.
+				$output = preg_replace('!\s{2,}!', ' ', $output);
+
+				// Remove comments (non-MSIE conditionals)
+				$output = preg_replace('{\s*<!--[^\[].*-->\s*}msU', '', $output);
+
+				// Remove spaces around block-level elements.
+				$output = preg_replace('/\s*(<\/?(html|head|title|meta|script|link|style|body|h[1-6]|div|p|br)[^>]*>)\s*/is', '$1', $output);
+
+				// Replace mangled <pre> etc. tags with unprocessed ones.
+
+				if ( ! empty($pres_clean))
+				{
+					preg_match_all('{<pre.+</pre>}msU', $output, $pres_messed);
+					$output = str_replace($pres_messed[0], $pres_clean[0], $output);
+				}
+
+				if ( ! empty($codes_clean))
+				{
+					preg_match_all('{<code.+</code>}msU', $output, $codes_messed);
+					$output = str_replace($codes_messed[0], $codes_clean[0], $output);
+				}
+
+				if ( ! empty($codes_clean))
+				{
+					preg_match_all('{<textarea.+</textarea>}msU', $output, $textareas_messed);
+					$output = str_replace($textareas_messed[0], $textareas_clean[0], $output);
+				}
+
+				if (isset($javascript_mini))
+				{
+					preg_match_all('{<script.+</script>}msU', $output, $javascript_messed);
+					$output = str_replace($javascript_messed[0], $javascript_mini, $output);
+				}
+
+				$size_removed = $size_before - strlen($output);
+				$savings_percent = round(($size_removed / $size_before * 100));
+
+				log_message('debug', 'Minifier shaved '.($size_removed / 1000).'KB ('.$savings_percent.'%) off final HTML output.');
+
+			break;
+
+			case 'text/css':
+
+				//Remove CSS comments
+				$output = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $output);
+
+				// Remove spaces around curly brackets, colons,
+				// semi-colons, parenthesis, commas
+				$output = preg_replace('!\s*(:|;|,|}|{|\(|\))\s*!', '$1', $output);
+
+			break;
+
+			case 'text/javascript':
+
+				// Currently leaves JavaScript untouched.
+			break;
+
+			default: break;
+		}
+
+		return $output;
+	}
+
 }
 
 /* End of file Output.php */
diff --git a/system/core/Router.php b/system/core/Router.php
index 5477fed5d..76772a0fb 100755..100644
--- a/system/core/Router.php
+++ b/system/core/Router.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Router Class
@@ -32,59 +33,60 @@
  *
  * @package		CodeIgniter
  * @subpackage	Libraries
- * @author		EllisLab Dev Team
  * @category	Libraries
+ * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/general/routing.html
  */
 class CI_Router {
 
 	/**
-	 * Config class
+	 * CI_Config class object
 	 *
-	 * @var object
+	 * @var	object
 	 */
 	public $config;
+
 	/**
 	 * List of routes
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $routes			= array();
-	/**
-	 * List of error routes
-	 *
-	 * @var array
-	 */
-	public $error_routes	= array();
+	public $routes =	array();
+
 	/**
 	 * Current class name
 	 *
-	 * @var string
+	 * @var	string
 	 */
-	public $class			= '';
+	public $class =		'';
+
 	/**
 	 * Current method name
 	 *
-	 * @var string
+	 * @var	string
 	 */
-	public $method			= 'index';
+	public $method =	'index';
+
 	/**
 	 * Sub-directory that contains the requested controller class
 	 *
-	 * @var string
+	 * @var	string
 	 */
-	public $directory		= '';
+	public $directory =	'';
+
 	/**
 	 * Default controller (and method if specific)
 	 *
-	 * @var string
+	 * @var	string
 	 */
 	public $default_controller;
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Runs the route mapping function.
+	 *
+	 * @return	void
 	 */
 	public function __construct()
 	{
@@ -96,9 +98,9 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the route mapping
+	 * Set route mapping
 	 *
-	 * This function determines what should be served based on the URI request,
+	 * Determines what should be served based on the URI request,
 	 * as well as any "routes" that have been set in the routing config file.
 	 *
 	 * @return	void
@@ -109,21 +111,21 @@ class CI_Router {
 		// since URI segments are more search-engine friendly, but they can optionally be used.
 		// If this feature is enabled, we will gather the directory/class/method a little differently
 		$segments = array();
-		if ($this->config->item('enable_query_strings') === TRUE && isset($_GET[$this->config->item('controller_trigger')]))
+		if ($this->config->item('enable_query_strings') === TRUE
+			&& ! empty($_GET[$this->config->item('controller_trigger')])
+			&& is_string($_GET[$this->config->item('controller_trigger')])
+		)
 		{
-			if (isset($_GET[$this->config->item('directory_trigger')]))
+			if (isset($_GET[$this->config->item('directory_trigger')]) && is_string($_GET[$this->config->item('directory_trigger')]))
 			{
 				$this->set_directory(trim($this->uri->_filter_uri($_GET[$this->config->item('directory_trigger')])));
 				$segments[] = $this->fetch_directory();
 			}
 
-			if (isset($_GET[$this->config->item('controller_trigger')]))
-			{
-				$this->set_class(trim($this->uri->_filter_uri($_GET[$this->config->item('controller_trigger')])));
-				$segments[] = $this->fetch_class();
-			}
+			$this->set_class(trim($this->uri->_filter_uri($_GET[$this->config->item('controller_trigger')])));
+			$segments[] = $this->fetch_class();
 
-			if (isset($_GET[$this->config->item('function_trigger')]))
+			if ( ! empty($_GET[$this->config->item('function_trigger')]) && is_string($_GET[$this->config->item('function_trigger')]))
 			{
 				$this->set_method(trim($this->uri->_filter_uri($_GET[$this->config->item('function_trigger')])));
 				$segments[] = $this->fetch_method();
@@ -140,12 +142,12 @@ class CI_Router {
 			include(APPPATH.'config/routes.php');
 		}
 
-		$this->routes = ( ! isset($route) OR ! is_array($route)) ? array() : $route;
+		$this->routes = (empty($route) OR ! is_array($route)) ? array() : $route;
 		unset($route);
 
 		// Set the default controller so we can display it in the event
 		// the URI doesn't correlated to a valid controller.
-		$this->default_controller = empty($this->routes['default_controller']) ? FALSE : strtolower($this->routes['default_controller']);
+		$this->default_controller = empty($this->routes['default_controller']) ? FALSE : $this->routes['default_controller'];
 
 		// Were there any query string segments? If so, we'll validate them and bail out since we're done.
 		if (count($segments) > 0)
@@ -171,31 +173,27 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the default controller
+	 * Set default controller
 	 *
 	 * @return	void
 	 */
 	protected function _set_default_controller()
 	{
-		if ($this->default_controller === FALSE)
+		if (empty($this->default_controller))
 		{
 			show_error('Unable to determine what should be displayed. A default route has not been specified in the routing file.');
 		}
+
 		// Is the method being specified?
-		if (strpos($this->default_controller, '/') !== FALSE)
-		{
-			$x = explode('/', $this->default_controller);
-			$this->set_class($x[0]);
-			$this->set_method($x[1]);
-			$this->_set_request($x);
-		}
-		else
+		if (sscanf($this->default_controller, '%[^/]/%s', $class, $method) !== 2)
 		{
-			$this->set_class($this->default_controller);
-			$this->set_method('index');
-			$this->_set_request(array($this->default_controller, 'index'));
+			$method = 'index';
 		}
 
+		$this->set_class($class);
+		$this->set_method($method);
+		$this->_set_request(array($class, $method));
+
 		// re-index the routed segments array so it starts with 1 rather than 0
 		$this->uri->_reindex_segments();
 
@@ -205,13 +203,12 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the Route
+	 * Set request route
 	 *
-	 * This function takes an array of URI segments as
-	 * input, and sets the current class/method
+	 * Takes an array of URI segments as input and sets the class/method
+	 * to be called.
 	 *
-	 * @param	array
-	 * @param	bool
+	 * @param	array	$segments	URI segments
 	 * @return	void
 	 */
 	protected function _set_request($segments = array())
@@ -225,17 +222,8 @@ class CI_Router {
 
 		$this->set_class($segments[0]);
 
-		if (isset($segments[1]))
-		{
-			// A standard method request
-			$this->set_method($segments[1]);
-		}
-		else
-		{
-			// This lets the "routed" segment array identify that the default
-			// index method is being used.
-			$segments[1] = 'index';
-		}
+		isset($segments[1]) OR $segments[1] = 'index';
+		$this->set_method($segments[1]);
 
 		// Update our "routed" segment array to contain the segments.
 		// Note: If there is no custom routing, this array will be
@@ -246,11 +234,12 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Validates the supplied segments.
-	 * Attempts to determine the path to the controller.
+	 * Validate request
+	 *
+	 * Attempts validate the URI request and determine the controller path.
 	 *
-	 * @param	array
-	 * @return	array
+	 * @param	array	$segments	URI segments
+	 * @return	array	URI segments
 	 */
 	protected function _validate_request($segments)
 	{
@@ -259,9 +248,13 @@ class CI_Router {
 			return $segments;
 		}
 
+		$temp = str_replace('-', '_', $segments[0]);
+
 		// Does the requested controller exist in the root folder?
-		if (file_exists(APPPATH.'controllers/'.$segments[0].'.php'))
+		if (file_exists(APPPATH.'controllers/'.$temp.'.php'))
 		{
+			$segments[0] = $temp;
+			empty($segments[1]) OR $segments[1] = str_replace('-', '_', $segments[1]);
 			return $segments;
 		}
 
@@ -269,22 +262,19 @@ class CI_Router {
 		if (is_dir(APPPATH.'controllers/'.$segments[0]))
 		{
 			// Set the directory and remove it from the segment array
-			$this->set_directory($segments[0]);
-			$segments = array_slice($segments, 1);
-
+			$this->set_directory(array_shift($segments));
 			if (count($segments) > 0)
 			{
+				$segments[0] = str_replace('-', '_', $segments[0]);
+				empty($segments[1]) OR $segments[1] = str_replace('-', '_', $segments[1]);
+
 				// Does the requested controller exist in the sub-folder?
 				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].'.php'))
 				{
 					if ( ! empty($this->routes['404_override']))
 					{
-						$x = explode('/', $this->routes['404_override']);
-						$this->set_directory('');
-						$this->set_class($x[0]);
-						$this->set_method(isset($x[1]) ? $x[1] : 'index');
-
-						return $x;
+						$this->directory = '';
+						return explode('/', $this->routes['404_override'], 2);
 					}
 					else
 					{
@@ -295,40 +285,26 @@ class CI_Router {
 			else
 			{
 				// Is the method being specified in the route?
-				if (strpos($this->default_controller, '/') !== FALSE)
-				{
-					$x = explode('/', $this->default_controller);
-					$this->set_class($x[0]);
-					$this->set_method($x[1]);
-				}
-				else
-				{
-					$this->set_class($this->default_controller);
-					$this->set_method('index');
-				}
-
-				// Does the default controller exist in the sub-folder?
-				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.'.php'))
+				$segments = explode('/', $this->default_controller);
+				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].'.php'))
 				{
 					$this->directory = '';
-					return array();
 				}
-
 			}
 
 			return $segments;
 		}
 
-
 		// If we've gotten this far it means that the URI does not correlate to a valid
 		// controller class. We will now see if there is an override
 		if ( ! empty($this->routes['404_override']))
 		{
-			$x = explode('/', $this->routes['404_override']);
-			$this->set_class($x[0]);
-			$this->set_method(isset($x[1]) ? $x[1] : 'index');
+			if (sscanf($this->routes['404_override'], '%[^/]/%s', $class, $method) !== 2)
+			{
+				$method = 'index';
+			}
 
-			return $x;
+			return array($class, $method);
 		}
 
 		// Nothing else to do at this point but show a 404
@@ -340,9 +316,8 @@ class CI_Router {
 	/**
 	 * Parse Routes
 	 *
-	 * This function matches any routes that may exist in
-	 * the config/routes.php file against the URI to
-	 * determine if the class/method need to be remapped.
+	 * Matches any routes that may exist in the config/routes.php file
+	 * against the URI to determine if the class/method need to be remapped.
 	 *
 	 * @return	void
 	 */
@@ -352,7 +327,7 @@ class CI_Router {
 		$uri = implode('/', $this->uri->segments);
 
 		// Is there a literal match?  If so we're done
-		if (isset($this->routes[$uri]))
+		if (isset($this->routes[$uri]) && is_string($this->routes[$uri]))
 		{
 			return $this->_set_request(explode('/', $this->routes[$uri]));
 		}
@@ -361,13 +336,51 @@ class CI_Router {
 		foreach ($this->routes as $key => $val)
 		{
 			// Convert wild-cards to RegEx
-			$key = str_replace(array(':any', ':num'), array('.+', '[0-9]+'), $key);
+			$key = str_replace(array(':any', ':num'), array('[^/]+', '[0-9]+'), $key);
 
 			// Does the RegEx match?
-			if (preg_match('#^'.$key.'$#', $uri))
+			if (preg_match('#^'.$key.'$#', $uri, $matches))
 			{
-				// Do we have a back-reference?
-				if (strpos($val, '$') !== FALSE && strpos($key, '(') !== FALSE)
+				// Are we using callbacks to process back-references?
+				if ( ! is_string($val) && is_callable($val))
+				{
+					// Remove the original string from the matches array.
+					array_shift($matches);
+
+					// Get the match count.
+					$match_count = count($matches);
+
+					// Determine how many parameters the callback has.
+					$reflection = new ReflectionFunction($val);
+					$param_count = $reflection->getNumberOfParameters();
+
+					// Are there more parameters than matches?
+					if ($param_count > $match_count)
+					{
+						// Any params without matches will be set to an empty string.
+						$matches = array_merge($matches, array_fill($match_count, $param_count - $match_count, ''));
+
+						$match_count = $param_count;
+					}
+
+					// Get the parameters so we can use their default values.
+					$params = $reflection->getParameters();
+
+					for ($m = 0; $m < $match_count; $m++)
+					{
+						// Is the match empty and does a default value exist?
+						if (empty($matches[$m]) && $params[$m]->isDefaultValueAvailable())
+						{
+							// Substitute the empty match for the default value.
+							$matches[$m] = $params[$m]->getDefaultValue();
+						}
+					}
+
+					// Execute the callback using the values in matches as its parameters.
+					$val = call_user_func_array($val, $matches);
+				}
+				// Are we using the default routing method for back-references?
+				elseif (strpos($val, '$') !== FALSE && strpos($key, '(') !== FALSE)
 				{
 					$val = preg_replace('#^'.$key.'$#', $val, $uri);
 				}
@@ -384,9 +397,9 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the class name
+	 * Set class name
 	 *
-	 * @param	string
+	 * @param	string	$class	Class name
 	 * @return	void
 	 */
 	public function set_class($class)
@@ -409,9 +422,9 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the method name
+	 * Set method name
 	 *
-	 * @param	string
+	 * @param	string	$method	Method name
 	 * @return	void
 	 */
 	public function set_method($method)
@@ -428,20 +441,15 @@ class CI_Router {
 	 */
 	public function fetch_method()
 	{
-		if ($this->method == $this->fetch_class())
-		{
-			return 'index';
-		}
-
-		return $this->method;
+		return ($this->method === $this->fetch_class()) ? 'index' : $this->method;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the directory name
+	 * Set directory name
 	 *
-	 * @param	string
+	 * @param	string	$dir	Directory name
 	 * @return	void
 	 */
 	public function set_directory($dir)
@@ -452,7 +460,10 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch the sub-directory (if any) that contains the requested controller class
+	 * Fetch directory
+	 *
+	 * Feches the sub-directory (if any) that contains the requested
+	 * controller class.
 	 *
 	 * @return	string
 	 */
@@ -464,9 +475,9 @@ class CI_Router {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the controller overrides
+	 * Set controller overrides
 	 *
-	 * @param	array
+	 * @param	array	$routing	Route overrides
 	 * @return	void
 	 */
 	public function _set_overrides($routing)
@@ -481,14 +492,14 @@ class CI_Router {
 			$this->set_directory($routing['directory']);
 		}
 
-		if (isset($routing['controller']) && $routing['controller'] != '')
+		if ( ! empty($routing['controller']))
 		{
 			$this->set_class($routing['controller']);
 		}
 
 		if (isset($routing['function']))
 		{
-			$routing['function'] = ($routing['function'] == '') ? 'index' : $routing['function'];
+			$routing['function'] = empty($routing['function']) ? 'index' : $routing['function'];
 			$this->set_method($routing['function']);
 		}
 	}
diff --git a/system/core/Security.php b/system/core/Security.php
index ac39ce97b..c415544b6 100755..100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Security Class
@@ -37,71 +38,87 @@
 class CI_Security {
 
 	/**
-	 * Random Hash for protecting URLs
+	 * XSS Hash
 	 *
-	 * @var string
+	 * Random Hash for protecting URLs.
+	 *
+	 * @var	string
 	 */
-	protected $_xss_hash			= '';
+	protected $_xss_hash =	'';
 
 	/**
-	 * Random Hash for Cross Site Request Forgery Protection Cookie
+	 * CSRF Hash
+	 *
+	 * Random hash for Cross Site Request Forgery protection cookie
 	 *
-	 * @var string
+	 * @var	string
 	 */
-	protected $_csrf_hash			= '';
+	protected $_csrf_hash =	'';
 
 	/**
-	 * Expiration time for Cross Site Request Forgery Protection Cookie
-	 * Defaults to two hours (in seconds)
+	 * CSRF Expire time
+	 *
+	 * Expiration time for Cross Site Request Forgery protection cookie.
+	 * Defaults to two hours (in seconds).
 	 *
-	 * @var int
+	 * @var	int
 	 */
-	protected $_csrf_expire			= 7200;
+	protected $_csrf_expire =	7200;
 
 	/**
-	 * Token name for Cross Site Request Forgery Protection Cookie
+	 * CSRF Token name
 	 *
-	 * @var string
+	 * Token name for Cross Site Request Forgery protection cookie.
+	 *
+	 * @var	string
 	 */
-	protected $_csrf_token_name		= 'ci_csrf_token';
+	protected $_csrf_token_name =	'ci_csrf_token';
 
 	/**
-	 * Cookie name for Cross Site Request Forgery Protection Cookie
+	 * CSRF Cookie name
+	 *
+	 * Cookie name for Cross Site Request Forgery protection cookie.
 	 *
-	 * @var string
+	 * @var	string
 	 */
-	protected $_csrf_cookie_name		= 'ci_csrf_token';
+	protected $_csrf_cookie_name =	'ci_csrf_token';
 
 	/**
 	 * List of never allowed strings
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	protected $_never_allowed_str = array(
-						'document.cookie'	=> '[removed]',
-						'document.write'	=> '[removed]',
-						'.parentNode'		=> '[removed]',
-						'.innerHTML'		=> '[removed]',
-						'window.location'	=> '[removed]',
-						'-moz-binding'		=> '[removed]',
-						'<!--'				=> '&lt;!--',
-						'-->'				=> '--&gt;',
-						'<![CDATA['			=> '&lt;![CDATA[',
-						'<comment>'			=> '&lt;comment&gt;'
-					);
+	protected $_never_allowed_str =	array(
+		'document.cookie'	=> '[removed]',
+		'document.write'	=> '[removed]',
+		'.parentNode'		=> '[removed]',
+		'.innerHTML'		=> '[removed]',
+		'window.location'	=> '[removed]',
+		'-moz-binding'		=> '[removed]',
+		'<!--'				=> '&lt;!--',
+		'-->'				=> '--&gt;',
+		'<![CDATA['			=> '&lt;![CDATA[',
+		'<comment>'			=> '&lt;comment&gt;'
+	);
 
 	/**
-	 * List of never allowed regex replacement
+	 * List of never allowed regex replacements
 	 *
-	 * @var array
+	 * @var	array
 	 */
 	protected $_never_allowed_regex = array(
-						'javascript\s*:',
-						'expression\s*(\(|&\#40;)', // CSS and IE
-						'vbscript\s*:', // IE, surprise!
-						'Redirect\s+302'
-					);
+		'javascript\s*:',
+		'expression\s*(\(|&\#40;)', // CSS and IE
+		'vbscript\s*:', // IE, surprise!
+		'Redirect\s+302',
+		"([\"'])?data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?"
+	);
 
+	/**
+	 * Class constructor
+	 *
+	 * @return	void
+	 */
 	public function __construct()
 	{
 		// Is CSRF protection enabled?
@@ -132,7 +149,7 @@ class CI_Security {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Verify Cross Site Request Forgery Protection
+	 * CSRF Verify
 	 *
 	 * @return	object
 	 */
@@ -155,8 +172,8 @@ class CI_Security {
 		}
 
 		// Do the tokens exist in both the _POST and _COOKIE arrays?
-		if ( ! isset($_POST[$this->_csrf_token_name]) OR ! isset($_COOKIE[$this->_csrf_cookie_name])
-			OR $_POST[$this->_csrf_token_name] != $_COOKIE[$this->_csrf_cookie_name]) // Do the tokens match?
+		if ( ! isset($_POST[$this->_csrf_token_name], $_COOKIE[$this->_csrf_cookie_name])
+			OR $_POST[$this->_csrf_token_name] !== $_COOKIE[$this->_csrf_cookie_name]) // Do the tokens match?
 		{
 			$this->csrf_show_error();
 		}
@@ -182,8 +199,9 @@ class CI_Security {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set Cross Site Request Forgery Protection Cookie
+	 * CSRF Set Cookie
 	 *
+	 * @codeCoverageIgnore
 	 * @return	object
 	 */
 	public function csrf_set_cookie()
@@ -191,17 +209,17 @@ 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;
 		}
 
 		setcookie(
-			$this->_csrf_cookie_name, 
-			$this->_csrf_hash, 
-			$expire, 
-			config_item('cookie_path'), 
-			config_item('cookie_domain'), 
+			$this->_csrf_cookie_name,
+			$this->_csrf_hash,
+			$expire,
+			config_item('cookie_path'),
+			config_item('cookie_domain'),
 			$secure_cookie,
 			config_item('cookie_httponly')
 		);
@@ -227,9 +245,8 @@ class CI_Security {
 	/**
 	 * Get CSRF Hash
 	 *
-	 * Getter Method
-	 *
-	 * @return 	string 	self::_csrf_hash
+	 * @see		CI_Security::$_csrf_hash
+	 * @return 	string	CSRF hash
 	 */
 	public function get_csrf_hash()
 	{
@@ -241,9 +258,8 @@ class CI_Security {
 	/**
 	 * Get CSRF Token Name
 	 *
-	 * Getter Method
-	 *
-	 * @return 	string 	self::_csrf_token_name
+	 * @see		CI_Security::$_csrf_token_name
+	 * @return	string	CSRF token name
 	 */
 	public function get_csrf_token_name()
 	{
@@ -256,26 +272,26 @@ class CI_Security {
 	 * XSS Clean
 	 *
 	 * Sanitizes data so that Cross Site Scripting Hacks can be
-	 * prevented.  This function does a fair amount of work but
+	 * prevented.  This method does a fair amount of work but
 	 * it is extremely thorough, designed to prevent even the
 	 * most obscure XSS attempts.  Nothing is ever 100% foolproof,
 	 * of course, but I haven't been able to get anything passed
 	 * the filter.
 	 *
-	 * Note: This function should only be used to deal with data
-	 * upon submission. It's not something that should
-	 * be used for general runtime processing.
+	 * Note: Should only be used to deal with data upon submission.
+	 *	 It's not something that should be used for general
+	 *	 runtime processing.
 	 *
-	 * This function was based in part on some code and ideas I
-	 * got from Bitflux: http://channel.bitflux.ch/wiki/XSS_Prevention
+	 * @link	http://channel.bitflux.ch/wiki/XSS_Prevention
+	 * 		Based in part on some code and ideas from Bitflux.
 	 *
-	 * To help develop this script I used this great list of
-	 * vulnerabilities along with a few other hacks I've
-	 * harvested from examining vulnerabilities in other programs:
-	 * http://ha.ckers.org/xss.html
+	 * @link	http://ha.ckers.org/xss.html
+	 * 		To help develop this script I used this great list of
+	 *		vulnerabilities along with a few other hacks I've
+	 *		harvested from examining vulnerabilities in other programs.
 	 *
-	 * @param	mixed	string or array
-	 * @param 	bool
+	 * @param	string|string[]	$str		Input data
+	 * @param 	bool		$is_image	Whether the input is an image
 	 * @return	string
 	 */
 	public function xss_clean($str, $is_image = FALSE)
@@ -352,7 +368,7 @@ class CI_Security {
 		}
 		else
 		{
-			$str = str_replace(array('<?', '?'.'>'),  array('&lt;?', '?&gt;'), $str);
+			$str = str_replace(array('<?', '?'.'>'), array('&lt;?', '?&gt;'), $str);
 		}
 
 		/*
@@ -362,9 +378,9 @@ class CI_Security {
 		 * These words are compacted back to their correct state.
 		 */
 		$words = array(
-				'javascript', 'expression', 'vbscript', 'script',
-				'applet', 'alert', 'document', 'write', 'cookie', 'window'
-			);
+			'javascript', 'expression', 'vbscript', 'script', 'base64',
+			'applet', 'alert', 'document', 'write', 'cookie', 'window'
+		);
 
 		foreach ($words as $word)
 		{
@@ -387,20 +403,20 @@ class CI_Security {
 
 			if (preg_match('/<a/i', $str))
 			{
-				$str = preg_replace_callback('#<a\s+([^>]*?)(>|$)#si', array($this, '_js_link_removal'), $str);
+				$str = preg_replace_callback('#<a\s+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
 			}
 
 			if (preg_match('/<img/i', $str))
 			{
-				$str = preg_replace_callback('#<img\s+([^>]*?)(\s?/?>|$)#si', array($this, '_js_img_removal'), $str);
+				$str = preg_replace_callback('#<img\s+([^>]*?)(?:\s?/?>|$)#si', array($this, '_js_img_removal'), $str);
 			}
 
-			if (preg_match('/(script|xss)/i', $str))
+			if (preg_match('/script|xss/i', $str))
 			{
-				$str = preg_replace('#<(/*)(script|xss)(.*?)\>#si', '[removed]', $str);
+				$str = preg_replace('#</*(?:script|xss).*?>#si', '[removed]', $str);
 			}
 		}
-		while($original != $str);
+		while ($original !== $str);
 
 		unset($original);
 
@@ -461,13 +477,16 @@ class CI_Security {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Random Hash for protecting URLs
+	 * XSS Hash
 	 *
-	 * @return	string
+	 * Generates the XSS hash if needed and returns it.
+	 *
+	 * @see		CI_Security::$_xss_hash
+	 * @return	string	XSS hash
 	 */
 	public function xss_hash()
 	{
-		if ($this->_xss_hash == '')
+		if ($this->_xss_hash === '')
 		{
 			mt_srand();
 			$this->_xss_hash = md5(time() + mt_rand(0, 1999999999));
@@ -481,7 +500,7 @@ class CI_Security {
 	/**
 	 * HTML Entities Decode
 	 *
-	 * This function is a replacement for html_entity_decode()
+	 * A replacement for html_entity_decode()
 	 *
 	 * The reason we are not using html_entity_decode() by itself is because
 	 * while it is not technically correct to leave out the semicolon
@@ -489,8 +508,10 @@ class CI_Security {
 	 * correctly. html_entity_decode() does not convert entities without
 	 * semicolons, so we are left with our own little solution here. Bummer.
 	 *
-	 * @param	string
-	 * @param	string
+	 * @link	http://php.net/html-entity-decode
+	 *
+	 * @param	string	$str		Input
+	 * @param	string	$charset	Character set
 	 * @return	string
 	 */
 	public function entity_decode($str, $charset = NULL)
@@ -513,32 +534,32 @@ class CI_Security {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Filename Security
+	 * Sanitize Filename
 	 *
-	 * @param	string
-	 * @param 	bool
+	 * @param	string	$str		Input file name
+	 * @param 	bool	$relative_path	Whether to preserve paths
 	 * @return	string
 	 */
 	public function sanitize_filename($str, $relative_path = FALSE)
 	{
 		$bad = array(
-				'../', '<!--', '-->', '<', '>',
-				"'", '"', '&', '$', '#',
-				'{', '}', '[', ']', '=',
-				';', '?', '%20', '%22',
-				'%3c',		// <
-				'%253c',	// <
-				'%3e',		// >
-				'%0e',		// >
-				'%28',		// (
-				'%29',		// )
-				'%2528',	// (
-				'%26',		// &
-				'%24',		// $
-				'%3f',		// ?
-				'%3b',		// ;
-				'%3d'		// =
-			);
+			'../', '<!--', '-->', '<', '>',
+			"'", '"', '&', '$', '#',
+			'{', '}', '[', ']', '=',
+			';', '?', '%20', '%22',
+			'%3c',		// <
+			'%253c',	// <
+			'%3e',		// >
+			'%0e',		// >
+			'%28',		// (
+			'%29',		// )
+			'%2528',	// (
+			'%26',		// &
+			'%24',		// $
+			'%3f',		// ?
+			'%3b',		// ;
+			'%3d'		// =
+		);
 
 		if ( ! $relative_path)
 		{
@@ -553,13 +574,27 @@ class CI_Security {
 	// ----------------------------------------------------------------
 
 	/**
+	 * Strip Image Tags
+	 *
+	 * @param	string	$str
+	 * @return	string
+	 */
+	public function strip_image_tags($str)
+	{
+		return preg_replace(array('#<img\s+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img\s+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
+	}
+
+	// ----------------------------------------------------------------
+
+	/**
 	 * Compact Exploded Words
 	 *
-	 * Callback function for xss_clean() to remove whitespace from
-	 * things like j a v a s c r i p t
+	 * Callback method for xss_clean() to remove whitespace from
+	 * things like 'j a v a s c r i p t'.
 	 *
-	 * @param	type
-	 * @return	type
+	 * @used-by	CI_Security::xss_clean()
+	 * @param	array	$matches
+	 * @return	string
 	 */
 	protected function _compact_exploded_words($matches)
 	{
@@ -568,20 +603,26 @@ class CI_Security {
 
 	// --------------------------------------------------------------------
 
-	/*
-	 * Remove Evil HTML Attributes (like evenhandlers and style)
+	/**
+	 * Remove Evil HTML Attributes (like event handlers and style)
 	 *
 	 * It removes the evil attribute and either:
-	 * 	- Everything up until a space
-	 *		For example, everything between the pipes:
+	 *
+	 *  - Everything up until a space. For example, everything between the pipes:
+	 *
+	 *	<code>
 	 *		<a |style=document.write('hello');alert('world');| class=link>
-	 * 	- Everything inside the quotes
-	 *		For example, everything between the pipes:
+	 *	</code>
+	 *
+	 *  - Everything inside the quotes. For example, everything between the pipes:
+	 *
+	 *	<code>
 	 *		<a |style="document.write('hello'); alert('world');"| class="link">
+	 *	</code>
 	 *
-	 * @param string $str The string to check
-	 * @param boolean $is_image TRUE if this is an image
-	 * @return string The string with the evil attributes removed
+	 * @param	string	$str		The string to check
+	 * @param	bool	$is_image	Whether the input is an image
+	 * @return	string	The string with the evil attributes removed
 	 */
 	protected function _remove_evil_attributes($str, $is_image)
 	{
@@ -602,10 +643,11 @@ class CI_Security {
 			$attribs = array();
 
 			// find occurrences of illegal attribute strings without quotes
-			preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*([^\s]*)/is', $str, $matches, PREG_SET_ORDER);
+			preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', $str, $matches, PREG_SET_ORDER);
 
 			foreach ($matches as $attr)
 			{
+
 				$attribs[] = preg_quote($attr[0], '/');
 			}
 
@@ -620,7 +662,7 @@ class CI_Security {
 			// replace illegal attribute strings that are inside an html tag
 			if (count($attribs) > 0)
 			{
-				$str = preg_replace('/<(\/?[^><]+?)([^A-Za-z\-])('.implode('|', $attribs).')([\s><])([><]*)/i', '<$1$2$4$5', $str, -1, $count);
+				$str = preg_replace('/<(\/?[^><]+?)([^A-Za-z<>\-])(.*?)('.implode('|', $attribs).')(.*?)([\s><])([><]*)/i', '<$1 $3$5$6$7', $str, -1, $count);
 			}
 
 		} while ($count);
@@ -633,9 +675,10 @@ class CI_Security {
 	/**
 	 * Sanitize Naughty HTML
 	 *
-	 * Callback function for xss_clean() to remove naughty HTML elements
+	 * Callback method for xss_clean() to remove naughty HTML elements.
 	 *
-	 * @param	array
+	 * @used-by	CI_Security::xss_clean()
+	 * @param	array	$matches
 	 * @return	string
 	 */
 	protected function _sanitize_naughty_html($matches)
@@ -650,18 +693,20 @@ class CI_Security {
 	/**
 	 * JS Link Removal
 	 *
-	 * Callback function for xss_clean() to sanitize links
+	 * Callback method for xss_clean() to sanitize links.
+	 *
 	 * This limits the PCRE backtracks, making it more performance friendly
 	 * and prevents PREG_BACKTRACK_LIMIT_ERROR from being triggered in
-	 * PHP 5.2+ on link-heavy strings
+	 * PHP 5.2+ on link-heavy strings.
 	 *
-	 * @param	array
+	 * @used-by	CI_Security::xss_clean()
+	 * @param	array	$match
 	 * @return	string
 	 */
 	protected function _js_link_removal($match)
 	{
 		return str_replace($match[1],
-					preg_replace('#href=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
+					preg_replace('#href=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|data\s*:)#si',
 							'',
 							$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
 					),
@@ -673,18 +718,20 @@ class CI_Security {
 	/**
 	 * JS Image Removal
 	 *
-	 * Callback function for xss_clean() to sanitize image tags
+	 * Callback method for xss_clean() to sanitize image tags.
+	 *
 	 * This limits the PCRE backtracks, making it more performance friendly
 	 * and prevents PREG_BACKTRACK_LIMIT_ERROR from being triggered in
-	 * PHP 5.2+ on image tag heavy strings
+	 * PHP 5.2+ on image tag heavy strings.
 	 *
-	 * @param	array
+	 * @used-by	CI_Security::xss_clean()
+	 * @param	array	$match
 	 * @return	string
 	 */
 	protected function _js_img_removal($match)
 	{
 		return str_replace($match[1],
-					preg_replace('#src=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
+					preg_replace('#src=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
 							'',
 							$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
 					),
@@ -696,9 +743,8 @@ class CI_Security {
 	/**
 	 * Attribute Conversion
 	 *
-	 * Used as a callback for XSS Clean
-	 *
-	 * @param	array
+	 * @used-by	CI_Security::xss_clean()
+	 * @param	array	$match
 	 * @return	string
 	 */
 	protected function _convert_attribute($match)
@@ -711,9 +757,11 @@ class CI_Security {
 	/**
 	 * Filter Attributes
 	 *
-	 * Filters tag attributes for consistency and safety
+	 * Filters tag attributes for consistency and safety.
 	 *
-	 * @param	string
+	 * @used-by	CI_Security::_js_img_removal()
+	 * @used-by	CI_Security::_js_link_removal()
+	 * @param	string	$str
 	 * @return	string
 	 */
 	protected function _filter_attributes($str)
@@ -735,9 +783,8 @@ class CI_Security {
 	/**
 	 * HTML Entity Decode Callback
 	 *
-	 * Used as a callback for XSS Clean
-	 *
-	 * @param	array
+	 * @used-by	CI_Security::xss_clean()
+	 * @param	array	$match
 	 * @return	string
 	 */
 	protected function _decode_entity($match)
@@ -750,9 +797,8 @@ class CI_Security {
 	/**
 	 * Validate URL entities
 	 *
-	 * Called by xss_clean()
-	 *
-	 * @param 	string
+	 * @used-by	CI_Security::xss_clean()
+	 * @param 	string	$str
 	 * @return 	string
 	 */
 	protected function _validate_entities($str)
@@ -790,8 +836,7 @@ class CI_Security {
 	/**
 	 * Do Never Allowed
 	 *
-	 * A utility function for xss_clean()
-	 *
+	 * @used-by	CI_Security::xss_clean()
 	 * @param 	string
 	 * @return 	string
 	 */
@@ -801,7 +846,7 @@ class CI_Security {
 
 		foreach ($this->_never_allowed_regex as $regex)
 		{
-			$str = preg_replace('#'.$regex.'#i', '[removed]', $str);
+			$str = preg_replace('#'.$regex.'#is', '[removed]', $str);
 		}
 
 		return $str;
@@ -810,20 +855,20 @@ class CI_Security {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set Cross Site Request Forgery Protection Cookie
+	 * Set CSRF Hash and Cookie
 	 *
 	 * @return	string
 	 */
 	protected function _csrf_set_hash()
 	{
-		if ($this->_csrf_hash == '')
+		if ($this->_csrf_hash === '')
 		{
 			// If the cookie exists we will use it's value.
 			// We don't necessarily want to regenerate it with
 			// each page load since a page could contain embedded
 			// sub-pages causing this feature to fail
 			if (isset($_COOKIE[$this->_csrf_cookie_name]) &&
-				$_COOKIE[$this->_csrf_cookie_name] != '')
+				preg_match('#^[0-9a-f]{32}$#iS', $_COOKIE[$this->_csrf_cookie_name]) === 1)
 			{
 				return $this->_csrf_hash = $_COOKIE[$this->_csrf_cookie_name];
 			}
@@ -838,4 +883,4 @@ class CI_Security {
 }
 
 /* End of file Security.php */
-/* Location: ./system/core/Security.php */
+/* Location: ./system/core/Security.php */
\ No newline at end of file
diff --git a/system/core/URI.php b/system/core/URI.php
index 48bb7ae3c..900472b61 100755..100644
--- a/system/core/URI.php
+++ b/system/core/URI.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -22,9 +22,9 @@
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 1.0
+ * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * URI Class
@@ -40,37 +40,43 @@
 class CI_URI {
 
 	/**
-	 * List of cached uri segments
+	 * List of cached URI segments
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $keyval		= array();
+	public $keyval =	array();
+
 	/**
-	 * Current uri string
+	 * Current URI string
 	 *
-	 * @var string
+	 * @var	string
 	 */
 	public $uri_string;
+
 	/**
-	 * List of uri segments
+	 * List of URI segments
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $segments	= array();
+	public $segments =	array();
+
 	/**
-	 * Re-indexed list of uri segments
-	 * Starts at 1 instead of 0
+	 * Re-indexed list of URI segments
+	 *
+	 * Starts at 1 instead of 0.
 	 *
-	 * @var array
+	 * @var	array
 	 */
-	public $rsegments	= array();
+	public $rsegments =	array();
 
 	/**
-	 * Constructor
+	 * Class constructor
 	 *
 	 * Simply globalizes the $RTR object. The front
 	 * loads the Router class early on so it's not available
 	 * normally as other classes are.
+	 *
+	 * @return	void
 	 */
 	public function __construct()
 	{
@@ -81,10 +87,9 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Get the URI String
-	 *
-	 * Called by CI_Router
+	 * Fetch URI String
 	 *
+	 * @used-by	CI_Router
 	 * @return	void
 	 */
 	public function _fetch_uri_string()
@@ -94,36 +99,33 @@ class CI_URI {
 			// Is the request coming from the command line?
 			if ($this->_is_cli_request())
 			{
-				$this->_set_uri_string($this->_parse_cli_args());
+				$this->_set_uri_string($this->_parse_argv());
 				return;
 			}
 
-			// Let's try the REQUEST_URI first, this will work in most situations
-			if ($uri = $this->_detect_uri())
+			// Is there a PATH_INFO variable? This should be the easiest solution.
+			if (isset($_SERVER['PATH_INFO']))
 			{
-				$this->_set_uri_string($uri);
+				$this->_set_uri_string($_SERVER['PATH_INFO']);
 				return;
 			}
 
-			// Is there a PATH_INFO variable?
-			// Note: some servers seem to have trouble with getenv() so we'll test it two ways
-			$path = (isset($_SERVER['PATH_INFO'])) ? $_SERVER['PATH_INFO'] : @getenv('PATH_INFO');
-			if (trim($path, '/') != '' && $path !== '/'.SELF)
+			// Let's try REQUEST_URI then, this will work in most situations
+			if (($uri = $this->_parse_request_uri()) !== '')
 			{
-				$this->_set_uri_string($path);
+				$this->_set_uri_string($uri);
 				return;
 			}
 
-			// No PATH_INFO?... What about QUERY_STRING?
-			$path = (isset($_SERVER['QUERY_STRING'])) ? $_SERVER['QUERY_STRING'] : @getenv('QUERY_STRING');
-			if (trim($path, '/') != '')
+			// No REQUEST_URI either?... What about QUERY_STRING?
+			if (($uri = $this->_parse_query_string()) !== '')
 			{
-				$this->_set_uri_string($path);
+				$this->_set_uri_string($uri);
 				return;
 			}
 
 			// As a last ditch effort lets try using the $_GET array
-			if (is_array($_GET) && count($_GET) === 1 && trim(key($_GET), '/') != '')
+			if (is_array($_GET) && count($_GET) === 1 && trim(key($_GET), '/') !== '')
 			{
 				$this->_set_uri_string(key($_GET));
 				return;
@@ -136,138 +138,191 @@ class CI_URI {
 
 		$uri = strtoupper($this->config->item('uri_protocol'));
 
-		if ($uri === 'REQUEST_URI')
+		if ($uri === 'CLI')
 		{
-			$this->_set_uri_string($this->_detect_uri());
+			$this->_set_uri_string($this->_parse_argv());
 			return;
 		}
-		elseif ($uri === 'CLI')
+		elseif (method_exists($this, ($method = '_parse_'.strtolower($uri))))
 		{
-			$this->_set_uri_string($this->_parse_cli_args());
+			$this->_set_uri_string($this->$method());
 			return;
 		}
 
-		$path = (isset($_SERVER[$uri])) ? $_SERVER[$uri] : @getenv($uri);
-		$this->_set_uri_string($path);
+		$uri = isset($_SERVER[$uri]) ? $_SERVER[$uri] : @getenv($uri);
+		$this->_set_uri_string($uri);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set the URI String
+	 * Set URI String
 	 *
-	 * @param 	string
+	 * @param 	string	$str
 	 * @return	void
 	 */
-	public function _set_uri_string($str)
+	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), '/');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Detects the URI
+	 * Parse REQUEST_URI
 	 *
-	 * This function will detect the URI automatically and fix the query string
-	 * if necessary.
+	 * Will parse REQUEST_URI and automatically detect the URI from it,
+	 * while fixing the query string if necessary.
 	 *
+	 * @used-by	CI_URI::_fetch_uri_string()
 	 * @return	string
 	 */
-	protected function _detect_uri()
+	protected function _parse_request_uri()
 	{
-		if ( ! isset($_SERVER['REQUEST_URI']) OR ! isset($_SERVER['SCRIPT_NAME']))
+		if ( ! isset($_SERVER['REQUEST_URI'], $_SERVER['SCRIPT_NAME']))
 		{
 			return '';
 		}
 
-		$uri = $_SERVER['REQUEST_URI'];
+		$uri = parse_url($_SERVER['REQUEST_URI']);
+		$query = isset($uri['query']) ? $uri['query'] : '';
+		$uri = isset($uri['path']) ? rawurldecode($uri['path']) : '';
+
 		if (strpos($uri, $_SERVER['SCRIPT_NAME']) === 0)
 		{
-			$uri = substr($uri, strlen($_SERVER['SCRIPT_NAME']));
+			$uri = (string) substr($uri, strlen($_SERVER['SCRIPT_NAME']));
 		}
 		elseif (strpos($uri, dirname($_SERVER['SCRIPT_NAME'])) === 0)
 		{
-			$uri = substr($uri, strlen(dirname($_SERVER['SCRIPT_NAME'])));
+			$uri = (string) substr($uri, strlen(dirname($_SERVER['SCRIPT_NAME'])));
 		}
 
 		// This section ensures that even on servers that require the URI to be in the query string (Nginx) a correct
 		// URI is found, and also fixes the QUERY_STRING server var and $_GET array.
-		if (strncmp($uri, '?/', 2) === 0)
-		{
-			$uri = substr($uri, 2);
-		}
-		$parts = preg_split('#\?#i', $uri, 2);
-		$uri = $parts[0];
-		if (isset($parts[1]))
+		if (trim($uri, '/') === '' && strncmp($query, '/', 1) === 0)
 		{
-			$_SERVER['QUERY_STRING'] = $parts[1];
-			parse_str($_SERVER['QUERY_STRING'], $_GET);
+			$query = explode('?', $query, 2);
+			$uri = rawurldecode($query[0]);
+			$_SERVER['QUERY_STRING'] = isset($query[1]) ? $query[1] : '';
 		}
 		else
 		{
-			$_SERVER['QUERY_STRING'] = '';
-			$_GET = array();
+			$_SERVER['QUERY_STRING'] = $query;
 		}
 
-		if ($uri == '/' OR empty($uri))
+		parse_str($_SERVER['QUERY_STRING'], $_GET);
+
+		if ($uri === '/' OR $uri === '')
 		{
 			return '/';
 		}
 
-		$uri = parse_url($uri, PHP_URL_PATH);
-
 		// Do some final cleaning of the URI and return it
-		return str_replace(array('//', '../'), '/', trim($uri, '/'));
+		return $this->_remove_relative_directory($uri);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Remove relative directory (../) and multi slashes (///)
+	 *
+	 * Do some final cleaning of the URI and return it, currently only used in self::_parse_request_uri()
+	 *
+	 * @param	string	$url
+	 * @return	string
+	 */
+	protected function _remove_relative_directory($uri)
+	{
+		$uris = array();
+		$tok = strtok($uri, '/');
+		while ($tok !== FALSE)
+		{
+			if (( ! empty($tok) OR $tok === '0') && $tok !== '..')
+			{
+				$uris[] = $tok;
+			}
+			$tok = strtok('/');
+		}
+		return implode('/', $uris);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Parse QUERY_STRING
+	 *
+	 * Will parse QUERY_STRING and automatically detect the URI from it.
+	 *
+	 * @used-by	CI_URI::_fetch_uri_string()
+	 * @return	string
+	 */
+	protected function _parse_query_string()
+	{
+		$uri = isset($_SERVER['QUERY_STRING']) ? $_SERVER['QUERY_STRING'] : @getenv('QUERY_STRING');
+
+		if (trim($uri, '/') === '')
+		{
+			return '';
+		}
+		elseif (strncmp($uri, '/', 1) === 0)
+		{
+			$uri = explode('?', $uri, 2);
+			$_SERVER['QUERY_STRING'] = isset($uri[1]) ? $uri[1] : '';
+			$uri = rawurldecode($uri[0]);
+		}
+
+		parse_str($_SERVER['QUERY_STRING'], $_GET);
+
+		return $this->_remove_relative_directory($uri);
 	}
 
 	// --------------------------------------------------------------------
-	
+
 	/**
-	 * Is cli Request?
+	 * Is CLI Request?
 	 *
-	 * Duplicate of function from the Input class to test to see if a request was made from the command line
+	 * Duplicate of method from the Input class to test to see if
+	 * a request was made from the command line.
 	 *
-	 * @return 	boolean
+	 * @see		CI_Input::is_cli_request()
+	 * @used-by	CI_URI::_fetch_uri_string()
+	 * @return 	bool
 	 */
 	protected function _is_cli_request()
 	{
-		return (php_sapi_name() == 'cli') OR defined('STDIN');
+		return (php_sapi_name() === 'cli') OR defined('STDIN');
 	}
 
-	
 	// --------------------------------------------------------------------
 
 	/**
-	 * Parse cli arguments
+	 * Parse CLI arguments
 	 *
 	 * Take each command line argument and assume it is a URI segment.
 	 *
 	 * @return	string
 	 */
-	protected function _parse_cli_args()
+	protected function _parse_argv()
 	{
 		$args = array_slice($_SERVER['argv'], 1);
-		return $args ? '/' . implode('/', $args) : '';
+		return $args ? implode('/', $args) : '';
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Filter segments for malicious characters
+	 * Filter URI
 	 *
-	 * Called by CI_Router
+	 * Filters segments for malicious characters.
 	 *
-	 * @param	string
+	 * @used-by	CI_Router
+	 * @param	string	$str
 	 * @return	string
 	 */
 	public function _filter_uri($str)
 	{
-		if ($str != '' && $this->config->item('permitted_uri_chars') != '' && $this->config->item('enable_query_strings') == FALSE)
+		if ($str !== '' && $this->config->item('permitted_uri_chars') != '' && $this->config->item('enable_query_strings') === FALSE)
 		{
 			// preg_quote() in PHP 5.3 escapes -, so the str_replace() and addition of - to preg_quote() is to maintain backwards
 			// compatibility as many are unaware of how characters in the permitted_uri_chars will be parsed as a regex pattern
@@ -287,28 +342,32 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Remove the suffix from the URL if needed
+	 * Remove URL suffix
 	 *
-	 * Called by CI_Router
+	 * Removes the suffix from the URL if needed.
 	 *
+	 * @used-by	CI_Router
 	 * @return	void
 	 */
 	public function _remove_url_suffix()
 	{
-		if  ($this->config->item('url_suffix') != '')
+		$suffix = (string) $this->config->item('url_suffix');
+
+		if ($suffix !== '' && ($offset = strrpos($this->uri_string, $suffix)) !== FALSE)
 		{
-			$this->uri_string = preg_replace('|'.preg_quote($this->config->item('url_suffix')).'$|', '', $this->uri_string);
+			$this->uri_string = substr_replace($this->uri_string, '', $offset, strlen($suffix));
 		}
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Explode the URI Segments. The individual segments will
-	 * be stored in the $this->segments array.
+	 * Explode URI segments
 	 *
-	 * Called by CI_Router
+	 * The individual segments will be stored in the $this->segments array.
 	 *
+	 * @see		CI_URI::$segments
+	 * @used-by	CI_Router
 	 * @return	void
 	 */
 	public function _explode_segments()
@@ -318,7 +377,7 @@ class CI_URI {
 			// Filter segments for security
 			$val = trim($this->_filter_uri($val));
 
-			if ($val != '')
+			if ($val !== '')
 			{
 				$this->segments[] = $val;
 			}
@@ -326,16 +385,16 @@ class CI_URI {
 	}
 
 	// --------------------------------------------------------------------
+
 	/**
 	 * Re-index Segments
 	 *
-	 * This function re-indexes the $this->segment array so that it
-	 * starts at 1 rather than 0. Doing so makes it simpler to
-	 * use functions like $this->uri->segment(n) since there is
-	 * a 1:1 relationship between the segment array and the actual segments.
-	 *
-	 * Called by CI_Router
+	 * Re-indexes the CI_URI::$segment array so that it starts at 1 rather
+	 * than 0. Doing so makes it simpler to use methods like
+	 * CI_URI::segment(n) since there is a 1:1 relationship between the
+	 * segment array and the actual segments.
 	 *
+	 * @used-by	CI_Router
 	 * @return	void
 	 */
 	public function _reindex_segments()
@@ -349,68 +408,76 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch a URI Segment
-	 *
-	 * This function returns the URI segment based on the number provided.
+	 * Fetch URI Segment
 	 *
-	 * @param	integer
-	 * @param	bool
-	 * @return	string
+	 * @see		CI_URI::$segments
+	 * @param	int		$n		Index
+	 * @param	mixed		$no_result	What to return if the segment index is not found
+	 * @return	mixed
 	 */
-	public function segment($n, $no_result = FALSE)
+	public function segment($n, $no_result = NULL)
 	{
-		return ( ! isset($this->segments[$n])) ? $no_result : $this->segments[$n];
+		return isset($this->segments[$n]) ? $this->segments[$n] : $no_result;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch a URI "routed" Segment
+	 * Fetch URI "routed" Segment
 	 *
-	 * This function returns the re-routed URI segment (assuming routing rules are used)
-	 * based on the number provided.  If there is no routing this function returns the
-	 * same result as $this->segment()
+	 * Returns the re-routed URI segment (assuming routing rules are used)
+	 * based on the index provided. If there is no routing, will return
+	 * the same result as CI_URI::segment().
 	 *
-	 * @param	integer
-	 * @param	bool
-	 * @return	string
+	 * @see		CI_URI::$rsegments
+	 * @see		CI_URI::segment()
+	 * @param	int		$n		Index
+	 * @param	mixed		$no_result	What to return if the segment index is not found
+	 * @return	mixed
 	 */
-	public function rsegment($n, $no_result = FALSE)
+	public function rsegment($n, $no_result = NULL)
 	{
-		return ( ! isset($this->rsegments[$n])) ? $no_result : $this->rsegments[$n];
+		return isset($this->rsegments[$n]) ? $this->rsegments[$n] : $no_result;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Generate a key value pair from the URI string
+	 * URI to assoc
 	 *
-	 * This function generates and associative array of URI data starting
-	 * at the supplied segment. For example, if this is your URI:
+	 * Generates an associative array of URI data starting at the supplied
+	 * segment index. For example, if this is your URI:
 	 *
 	 *	example.com/user/search/name/joe/location/UK/gender/male
 	 *
-	 * You can use this function to generate an array with this prototype:
+	 * You can use this method to generate an array with this prototype:
 	 *
-	 * array (
-	 *			name => joe
-	 *			location => UK
-	 *			gender => male
-	 *		 )
+	 *	array (
+	 *		name => joe
+	 *		location => UK
+	 *		gender => male
+	 *	 )
 	 *
-	 * @param	integer	the starting segment number
-	 * @param	array	an array of default values
+	 * @param	int	$n		Index (default: 3)
+	 * @param	array	$default	Default values
 	 * @return	array
 	 */
 	public function uri_to_assoc($n = 3, $default = array())
 	{
 		return $this->_uri_to_assoc($n, $default, 'segment');
 	}
+
+	// --------------------------------------------------------------------
+
 	/**
-	 * Identical to above only it uses the re-routed segment array
+	 * Routed URI to assoc
 	 *
-	 * @param 	integer	the starting segment number
-	 * @param 	array	an array of default values
+	 * Identical to CI_URI::uri_to_assoc(), only it uses the re-routed
+	 * segment array.
+	 *
+	 * @see		CI_URI::uri_to_assoc()
+	 * @param 	int	$n		Index (default: 3)
+	 * @param 	array	$default	Default values
 	 * @return 	array
 	 */
 	public function ruri_to_assoc($n = 3, $default = array())
@@ -421,11 +488,15 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Generate a key value pair from the URI string or Re-routed URI string
+	 * Internal URI-to-assoc
+	 *
+	 * Generates a key/value pair from the URI string or re-routed URI string.
 	 *
-	 * @param	integer	the starting segment number
-	 * @param	array	an array of default values
-	 * @param	string	which array we should use
+	 * @used-by	CI_URI::uri_to_assoc()
+	 * @used-by	CI_URI::ruri_to_assoc()
+	 * @param	int	$n		Index (default: 3)
+	 * @param	array	$default	Default values
+	 * @param	string	$which		Array name ('segment' or 'rsegment')
 	 * @return	array
 	 */
 	protected function _uri_to_assoc($n = 3, $default = array(), $which = 'segment')
@@ -435,9 +506,11 @@ class CI_URI {
 			return $default;
 		}
 
-		if (isset($this->keyval[$n]))
+		in_array($which, array('segment', 'rsegment'), TRUE) OR $which = 'segment';
+
+		if (isset($this->keyval[$which], $this->keyval[$which][$n]))
 		{
-			return $this->keyval[$n];
+			return $this->keyval[$which][$n];
 		}
 
 		if ($which === 'segment')
@@ -453,18 +526,15 @@ class CI_URI {
 
 		if ($this->$total_segments() < $n)
 		{
-			if (count($default) === 0)
-			{
-				return array();
-			}
-
-			return array_fill_keys($default, FALSE);
+			return (count($default) === 0)
+				? array()
+				: array_fill_keys($default, NULL);
 		}
 
 		$segments = array_slice($this->$segment_array(), ($n - 1));
 		$i = 0;
 		$lastval = '';
-		$retval  = array();
+		$retval = array();
 		foreach ($segments as $seg)
 		{
 			if ($i % 2)
@@ -473,7 +543,7 @@ class CI_URI {
 			}
 			else
 			{
-				$retval[$seg] = FALSE;
+				$retval[$seg] = NULL;
 				$lastval = $seg;
 			}
 
@@ -486,29 +556,31 @@ class CI_URI {
 			{
 				if ( ! array_key_exists($val, $retval))
 				{
-					$retval[$val] = FALSE;
+					$retval[$val] = NULL;
 				}
 			}
 		}
 
 		// Cache the array for reuse
-		$this->keyval[$n] = $retval;
+		isset($this->keyval[$which]) OR $this->keyval[$which] = array();
+		$this->keyval[$which][$n] = $retval;
 		return $retval;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Generate a URI string from an associative array
+	 * Assoc to URI
 	 *
+	 * Generates a URI string from an associative array.
 	 *
-	 * @param	array	an associative array of key/values
-	 * @return	array
+	 * @param	array	$array	Input array of key/value pairs
+	 * @return	string	URI string
 	 */
 	public function assoc_to_uri($array)
 	{
 		$temp = array();
-		foreach ((array)$array as $key => $val)
+		foreach ((array) $array as $key => $val)
 		{
 			$temp[] = $key;
 			$temp[] = $val;
@@ -520,10 +592,12 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch a URI Segment and add a trailing slash
+	 * Slash segment
+	 *
+	 * Fetches an URI segment with a slash.
 	 *
-	 * @param	integer
-	 * @param	string
+	 * @param	int	$n	Index
+	 * @param	string	$where	Where to add the slash ('trailing' or 'leading')
 	 * @return	string
 	 */
 	public function slash_segment($n, $where = 'trailing')
@@ -534,10 +608,12 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch a URI Segment and add a trailing slash
+	 * Slash routed segment
 	 *
-	 * @param	integer
-	 * @param	string
+	 * Fetches an URI routed segment with a slash.
+	 *
+	 * @param	int	$n	Index
+	 * @param	string	$where	Where to add the slash ('trailing' or 'leading')
 	 * @return	string
 	 */
 	public function slash_rsegment($n, $where = 'trailing')
@@ -548,11 +624,16 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch a URI Segment and add a trailing slash - helper function
+	 * Internal Slash segment
+	 *
+	 * Fetches an URI Segment and adds a slash to it.
 	 *
-	 * @param	integer
-	 * @param	string
-	 * @param	string
+	 * @used-by	CI_URI::slash_segment()
+	 * @used-by	CI_URI::slash_rsegment()
+	 *
+	 * @param	int	$n	Index
+	 * @param	string	$where	Where to add the slash ('trailing' or 'leading')
+	 * @param	string	$which	Array name ('segment' or 'rsegment')
 	 * @return	string
 	 */
 	protected function _slash_segment($n, $where = 'trailing', $which = 'segment')
@@ -576,7 +657,7 @@ class CI_URI {
 	/**
 	 * Segment Array
 	 *
-	 * @return	array
+	 * @return	array	CI_URI::$segments
 	 */
 	public function segment_array()
 	{
@@ -588,7 +669,7 @@ class CI_URI {
 	/**
 	 * Routed Segment Array
 	 *
-	 * @return	array
+	 * @return	array	CI_URI::$rsegments
 	 */
 	public function rsegment_array()
 	{
@@ -600,7 +681,7 @@ class CI_URI {
 	/**
 	 * Total number of segments
 	 *
-	 * @return	integer
+	 * @return	int
 	 */
 	public function total_segments()
 	{
@@ -612,7 +693,7 @@ class CI_URI {
 	/**
 	 * Total number of routed segments
 	 *
-	 * @return	integer
+	 * @return	int
 	 */
 	public function total_rsegments()
 	{
@@ -622,29 +703,35 @@ class CI_URI {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch the entire URI string
+	 * Fetch URI string
 	 *
-	 * @return	string
+	 * @return	string	CI_URI::$uri_string
 	 */
 	public function uri_string()
 	{
 		return $this->uri_string;
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch the entire Re-routed URI string
+	 * Fetch Re-routed URI string
 	 *
 	 * @return	string
 	 */
 	public function ruri_string()
 	{
-		return '/'.implode('/', $this->rsegment_array());
+		global $RTR;
+
+		if (($dir = $RTR->fetch_directory()) === '/')
+		{
+			$dir = '';
+		}
+
+		return $dir.implode('/', $this->rsegment_array());
 	}
 
 }
 
 /* End of file URI.php */
-/* Location: ./system/core/URI.php */
+/* Location: ./system/core/URI.php */
\ No newline at end of file
diff --git a/system/core/Utf8.php b/system/core/Utf8.php
index ba3567453..5bc2dd5c9 100644
--- a/system/core/Utf8.php
+++ b/system/core/Utf8.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,8 +24,7 @@
  * @since		Version 2.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Utf8 Class
@@ -41,38 +40,40 @@
 class CI_Utf8 {
 
 	/**
-	 * Constructor
+	 * Class constructor
+	 *
+	 * Determines if UTF-8 support is to be enabled.
 	 *
-	 * Determines if UTF-8 support is to be enabled
+	 * @return	void
 	 */
 	public function __construct()
 	{
 		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
-			&& @ini_get('mbstring.func_overload') != 1	// 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
 		{
@@ -86,9 +87,11 @@ class CI_Utf8 {
 	/**
 	 * Clean UTF-8 strings
 	 *
-	 * Ensures strings are UTF-8
+	 * Ensures strings contain only valid UTF-8 characters.
 	 *
-	 * @param	string
+	 * @uses	CI_Utf8::_is_ascii()	Decide whether a conversion is needed
+	 *
+	 * @param	string	$str	String to clean
 	 * @return	string
 	 */
 	public function clean_string($str)
@@ -108,9 +111,9 @@ class CI_Utf8 {
 	 *
 	 * Removes all ASCII control characters except horizontal tabs,
 	 * line feeds, and carriage returns, as all others can cause
-	 * problems in XML
+	 * problems in XML.
 	 *
-	 * @param	string
+	 * @param	string	$str	String to clean
 	 * @return	string
 	 */
 	public function safe_ascii_for_xml($str)
@@ -123,11 +126,11 @@ class CI_Utf8 {
 	/**
 	 * Convert to UTF-8
 	 *
-	 * Attempts to convert a string to UTF-8
+	 * Attempts to convert a string to UTF-8.
 	 *
-	 * @param	string
-	 * @param	string	- input encoding
-	 * @return	string
+	 * @param	string	$str		Input string
+	 * @param	string	$encoding	Input encoding
+	 * @return	string	$str encoded in UTF-8 or FALSE on failure
 	 */
 	public function convert_to_utf8($str, $encoding)
 	{
@@ -135,7 +138,7 @@ class CI_Utf8 {
 		{
 			return @iconv($encoding, 'UTF-8', $str);
 		}
-		elseif (function_exists('mb_convert_encoding'))
+		elseif (MB_ENABLED === TRUE)
 		{
 			return @mb_convert_encoding($str, 'UTF-8', $encoding);
 		}
@@ -148,9 +151,9 @@ class CI_Utf8 {
 	/**
 	 * Is ASCII?
 	 *
-	 * Tests if a string is standard 7-bit ASCII or not
+	 * Tests if a string is standard 7-bit ASCII or not.
 	 *
-	 * @param	string
+	 * @param	string	$str	String to check
 	 * @return	bool
 	 */
 	protected function _is_ascii($str)
@@ -161,4 +164,4 @@ class CI_Utf8 {
 }
 
 /* End of file Utf8.php */
-/* Location: ./system/core/Utf8.php */
+/* Location: ./system/core/Utf8.php */
\ No newline at end of file