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>

1 files changed, 296 insertions, 227 deletions

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)