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

43 files changed, 731 insertions, 529 deletions

diff --git a/system/core/Common.php b/system/core/Common.php
index 1708653e7..c309d4192 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -431,6 +431,7 @@ if ( ! function_exists('set_status_header'))
 			300	=> 'Multiple Choices',
 			301	=> 'Moved Permanently',
 			302	=> 'Found',
+			303	=> 'See Other',
 			304	=> 'Not Modified',
 			305	=> 'Use Proxy',
 			307	=> 'Temporary Redirect',
@@ -462,18 +463,23 @@ if ( ! function_exists('set_status_header'))
 			505	=> 'HTTP Version Not Supported'
 		);
 
-		if ($code == '' OR ! is_numeric($code))
+		if (empty($code) OR ! is_numeric($code))
 		{
 			show_error('Status codes must be numeric', 500);
 		}
-		elseif (isset($stati[$code]) && $text === '')
-		{
-			$text = $stati[$code];
-		}
 
-		if ($text === '')
+		is_int($code) OR $code = (int) $code;
+
+		if (empty($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']) ? $_SERVER['SERVER_PROTOCOL'] : FALSE;
diff --git a/system/core/Config.php b/system/core/Config.php
index 3de1bcb96..4b4e5a7ba 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -225,25 +225,39 @@ class CI_Config {
 	 * Site URL
 	 * Returns base_url . index_page [. uri_string]
 	 *
-	 * @param	string	the URI string
+	 * @param	mixed	the URI string or an array of segments
 	 * @return	string
 	 */
 	public function site_url($uri = '')
 	{
-		if ($uri === '')
+		if (empty($uri))
 		{
 			return $this->slash_item('base_url').$this->item('index_page');
 		}
 
+		$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).$suffix;
+
+			if ($suffix !== '' && ($offset = strpos($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;
 	}
 
 	// -------------------------------------------------------------
@@ -280,15 +294,7 @@ 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 $uri;
diff --git a/system/core/Exceptions.php b/system/core/Exceptions.php
index 8c32085fe..bd9178dbd 100644
--- a/system/core/Exceptions.php
+++ b/system/core/Exceptions.php
@@ -143,7 +143,7 @@ class CI_Exceptions {
 			ob_end_flush();
 		}
 		ob_start();
-		include(APPPATH.'views/errors/'.$template.'.php');
+		include(VIEWPATH.'errors/'.$template.'.php');
 		$buffer = ob_get_contents();
 		ob_end_clean();
 		return $buffer;
@@ -177,7 +177,7 @@ class CI_Exceptions {
 			ob_end_flush();
 		}
 		ob_start();
-		include(APPPATH.'views/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 29fd88201..afbf4b453 100644
--- a/system/core/Hooks.php
+++ b/system/core/Hooks.php
@@ -39,7 +39,7 @@
 class CI_Hooks {
 
 	/**
-	 * Determines wether hooks are enabled
+	 * Determines whether hooks are enabled
 	 *
 	 * @var bool
 	 */
@@ -53,7 +53,7 @@ class CI_Hooks {
 	public $hooks =	array();
 
 	/**
-	 * Determines wether hook is in progress, used to prevent infinte loops
+	 * Determines whether hook is in progress, used to prevent infinte loops
 	 *
 	 * @var bool
 	 */
diff --git a/system/core/Output.php b/system/core/Output.php
index 5588ffe8e..5ec8c4bc0 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -67,7 +67,14 @@ class CI_Output {
 	public $mimes =		array();
 
 	/**
-	 * Determines wether profiler is enabled
+	 * Mime-type for the current page
+	 *
+	 * @var string
+	 */
+	protected $mime_type		= 'text/html';
+
+	/**
+	 * Determines whether profiler is enabled
 	 *
 	 * @var book
 	 */
@@ -78,7 +85,7 @@ class CI_Output {
 	 *
 	 * @var bool
 	 */
-	protected $_zlib_oc =	FALSE;
+	protected $_zlib_oc =		FALSE;
 
 	/**
 	 * List of profiler sections
@@ -174,7 +181,7 @@ class CI_Output {
 	 * how to permit header data to be saved with the cache data...
 	 *
 	 * @param	string
-	 * @param 	bool
+	 * @param	bool
 	 * @return	void
 	 */
 	public function set_header($header, $replace = TRUE)
@@ -218,6 +225,8 @@ class CI_Output {
 			}
 		}
 
+		$this->mime_type = $mime_type;
+
 		if (empty($charset))
 		{
 			$charset = config_item('charset');
@@ -292,6 +301,12 @@ class CI_Output {
 	 */
 	public function set_profiler_sections($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] = ($enable !== FALSE);
@@ -327,7 +342,7 @@ class CI_Output {
 	 * with any server headers and profile data. It also stops the
 	 * benchmark timer so the page rendering speed and memory usage can be shown.
 	 *
-	 * @param 	string
+	 * @param	string
 	 * @return	mixed
 	 */
 	public function _display($output = '')
@@ -353,6 +368,15 @@ class CI_Output {
 
 		// --------------------------------------------------------------------
 
+		// 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 $CI object above
@@ -450,7 +474,7 @@ class CI_Output {
 	/**
 	 * Write a Cache File
 	 *
-	 * @param 	string
+	 * @param	string
 	 * @return	void
 	 */
 	public function _write_cache($output)
@@ -493,6 +517,9 @@ 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);
 	}
 
 	// --------------------------------------------------------------------
@@ -500,8 +527,8 @@ class CI_Output {
 	/**
 	 * Update/serve a cached file
 	 *
-	 * @param 	object	config class
-	 * @param 	object	uri class
+	 * @param	object	config class
+	 * @param	object	uri class
 	 * @return	bool
 	 */
 	public function _display_cache(&$CFG, &$URI)
@@ -530,13 +557,22 @@ class CI_Output {
 			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 = trim(str_replace('TS--->', '', $match[1]));
+
+		// Has the file expired?
+		if ($_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));
@@ -544,6 +580,140 @@ class CI_Output {
 		return TRUE;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set the HTTP headers to match the server-side file cache settings
+	 * in order to reduce bandwidth.
+	 *
+	 * @param	int	timestamp of when the page was last modified
+	 * @param	int	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', $last_modified).' GMT');
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Reduce excessive size of HTML content.
+	 *
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	public function minify($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/Security.php b/system/core/Security.php
index 4593a1090..227217e75 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -561,6 +561,19 @@ class CI_Security {
 	// ----------------------------------------------------------------
 
 	/**
+	 * Strip Image Tags
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	public function strip_image_tags($str)
+	{
+		return preg_replace(array('#<img\s+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img\s+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
+	}
+
+	// ----------------------------------------------------------------
+
+	/**
 	 * Compact Exploded Words
 	 *
 	 * Callback function for xss_clean() to remove whitespace from
diff --git a/system/core/URI.php b/system/core/URI.php
index a997525ee..6a8b1a5ac 100644
--- a/system/core/URI.php
+++ b/system/core/URI.php
@@ -278,7 +278,7 @@ class CI_URI {
 		{
 			// preg_quote() in PHP 5.3 escapes -, so the str_replace() and addition of - to preg_quote() is to maintain backwards
 			// compatibility as many are unaware of how characters in the permitted_uri_chars will be parsed as a regex pattern
-			if ( ! preg_match('|^['.str_replace(array('\\-', '\-'), '-', preg_quote($this->config->item('permitted_uri_chars'), '-')).']+$|i', $str))
+			if ( ! preg_match('|^['.str_replace(array('\\-', '\-'), '-', preg_quote($this->config->item('permitted_uri_chars'), '-')).']+$|i', urldecode($str)))
 			{
 				show_error('The URI you submitted has disallowed characters.', 400);
 			}
@@ -302,9 +302,11 @@ class CI_URI {
 	 */
 	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));
 		}
 	}
 
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index d056bdb90..739b25187 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -295,7 +295,7 @@ abstract class CI_DB_driver {
 	 * @param	array	An array of binding data
 	 * @return	mixed
 	 */
-	public function query($sql, $binds = FALSE, $return_object = TRUE)
+	public function query($sql, $binds = FALSE, $return_object = NULL)
 	{
 		if ($sql === '')
 		{
@@ -303,6 +303,10 @@ abstract class CI_DB_driver {
 
 			return ($this->db_debug) ? $this->display_error('db_invalid_query') : FALSE;
 		}
+		elseif ( ! is_bool($return_object))
+		{
+			$return_object = ! $this->is_write_type($sql);
+		}
 
 		// Verify table prefix and replace if necessary
 		if ($this->dbprefix !== '' && $this->swap_pre !== '' && $this->dbprefix !== $this->swap_pre)
@@ -319,7 +323,7 @@ abstract class CI_DB_driver {
 		// Is query caching enabled? If the query is a "read type"
 		// we will load the caching class and return the previously
 		// cached query if it exists
-		if ($this->cache_on === TRUE && stripos($sql, 'SELECT') !== FALSE && $this->_cache_init())
+		if ($this->cache_on === TRUE && $return_object === TRUE && $this->_cache_init())
 		{
 			$this->load_rdriver();
 			if (FALSE !== ($cache = $this->CACHE->read($sql)))
@@ -328,7 +332,7 @@ abstract class CI_DB_driver {
 			}
 		}
 
-		// Save the  query for debugging
+		// Save the query for debugging
 		if ($this->save_queries === TRUE)
 		{
 			$this->queries[] = $sql;
@@ -352,7 +356,7 @@ abstract class CI_DB_driver {
 			$error = $this->error();
 
 			// Log errors
-			log_message('error', 'Query error: '.$error['message']);
+			log_message('error', 'Query error: '.$error['message'].' - Invalid query: '.$sql);
 
 			if ($this->db_debug)
 			{
@@ -381,12 +385,10 @@ abstract class CI_DB_driver {
 		// Increment the query counter
 		$this->query_count++;
 
-		// Was the query a "write" type?
-		// If so we'll simply return true
-		if ($this->is_write_type($sql) === TRUE)
+		// Will we have a result object instantiated? If not - we'll simply return TRUE
+		if ($return_object !== TRUE)
 		{
-			// If caching is enabled we'll auto-cleanup any
-			// existing files related to this particular URI
+			// If caching is enabled we'll auto-cleanup any existing files related to this particular URI
 			if ($this->cache_on === TRUE && $this->cache_autodel === TRUE && $this->_cache_init())
 			{
 				$this->CACHE->delete();
@@ -396,8 +398,6 @@ abstract class CI_DB_driver {
 		}
 
 		// Return TRUE if we don't need to create a result object
-		// Currently only the Oracle driver uses this when stored
-		// procedures are used
 		if ($return_object !== TRUE)
 		{
 			return TRUE;
@@ -1086,6 +1086,20 @@ abstract class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Returns the SQL string operator
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	protected function _get_operator($str)
+	{
+		return preg_match('/(=|!|<|>| IS NULL| IS NOT NULL| BETWEEN)/i', $str, $match)
+			? $match[1] : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Enables a native PHP function to be run, using a platform agnostic wrapper.
 	 *
 	 * @param	string	the function name
@@ -1267,7 +1281,7 @@ abstract class CI_DB_driver {
 			if (isset($call['file']) && strpos($call['file'], BASEPATH.'database') === FALSE)
 			{
 				// Found it - use a relative path for safety
-				$message[] = 'Filename: '.str_replace(array(BASEPATH, APPPATH), '', $call['file']);
+				$message[] = 'Filename: '.str_replace(array(APPPATH, BASEPATH), '', $call['file']);
 				$message[] = 'Line Number: '.$call['line'];
 				break;
 			}
@@ -1336,39 +1350,21 @@ abstract class CI_DB_driver {
 		// Convert tabs or multiple spaces into single spaces
 		$item = preg_replace('/\s+/', ' ', $item);
 
-		static $preg_ec = array();
-
-		if (empty($preg_ec))
+		// If the item has an alias declaration we remove it and set it aside.
+		// Note: strripos() is used in order to support spaces in table names
+		if ($offset = strripos($item, ' AS '))
 		{
-			if (is_array($this->_escape_char))
-			{
-				$preg_ec = array(preg_quote($this->_escape_char[0]), preg_quote($this->_escape_char[1]));
-			}
-			else
-			{
-				$preg_ec[0] = $preg_ec[1] = preg_quote($this->_escape_char);
-			}
+			$alias = ($protect_identifiers)
+					? substr($item, $offset, 4).$this->escape_identifiers(substr($item, $offset + 4))
+					: substr($item, $offset);
+			$item = substr($item, 0, $offset);
 		}
-
-		// If the item has an alias declaration we remove it and set it aside.
-		// Basically we remove everything to the right of the first space
-		preg_match('/^(('.$preg_ec[0].'[^'.$preg_ec[1].']+'.$preg_ec[1].')|([^'.$preg_ec[0].'][^\s]+))( AS)*(.+)*$/i', $item, $matches);
-
-		if (isset($matches[4]))
+		elseif ($offset = strrpos($item, ' '))
 		{
-			$item = $matches[1];
-
-			// Escape the alias, if needed
-			if ($protect_identifiers === TRUE)
-			{
-				$alias = empty($matches[5])
-					? ' '.$this->escape_identifiers(ltrim($matches[4]))
-					: $matches[4].' '.$this->escape_identifiers(ltrim($matches[5]));
-			}
-			else
-			{
-				$alias = $matches[4].$matches[5];
-			}
+			$alias = ($protect_identifiers)
+					? ' '.$this->escape_identifiers(substr($item, $offset + 1))
+					: substr($item, $offset);
+			$item = substr($item, 0, $offset);
 		}
 		else
 		{
diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 9b7639289..91f9d560c 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -231,7 +231,7 @@ abstract class CI_DB_forge {
 
 		if (($result = $this->db->query($sql)) !== FALSE && ! empty($this->db->data_cache['table_names']))
 		{
-			$this->db->data_cache['table_names'][] = $$this->db->dbprefix.$table;
+			$this->db->data_cache['table_names'][] = $this->db->dbprefix.$table;
 		}
 
 		return $result;
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index 488b294e4..3982885e8 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -324,10 +324,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	string
 	 * @param	string	the join condition
 	 * @param	string	the type of join
-	 * @param	string	wether not to try to escape identifiers
+	 * @param	string	whether not to try to escape identifiers
 	 * @return	object
 	 */
-	public function join($table, $cond, $type = '', $escape = TRUE)
+	public function join($table, $cond, $type = '', $escape = NULL)
 	{
 		if ($type !== '')
 		{
@@ -347,6 +347,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		// in the protect_identifiers to know whether to add a table prefix
 		$this->_track_aliases($table);
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		// Split multiple conditions
 		if ($escape === TRUE && preg_match_all('/\sAND\s|\sOR\s/i', $cond, $m, PREG_SET_ORDER | PREG_OFFSET_CAPTURE))
 		{
@@ -366,12 +368,20 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				$newcond .= $m[0][$i][0];
 			}
 
-			$cond = $newcond;
+			$cond = ' ON '.$newcond;
 		}
 		// Split apart the condition and protect the identifiers
 		elseif ($escape === TRUE && preg_match('/([\[\w\.-]+)([\W\s]+)(.+)/i', $cond, $match))
 		{
-			$cond = $this->protect_identifiers($match[1]).$match[2].$this->protect_identifiers($match[3]);
+			$cond = ' ON '.$this->protect_identifiers($match[1]).$match[2].$this->protect_identifiers($match[3]);
+		}
+		elseif ( ! $this->_has_operator($cond))
+		{
+			$cond = ' USING ('.($escape ? $this->escape_identifiers($cond) : $cond).')';
+		}
+		else
+		{
+			$cond = ' ON '.$cond;
 		}
 
 		// Do we want to escape the table name?
@@ -381,7 +391,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		}
 
 		// Assemble the JOIN statement
-		$this->qb_join[] = $join = $type.'JOIN '.$this->protect_identifiers($table, TRUE, NULL, FALSE).' ON '.$cond;
+		$this->qb_join[] = $join = $type.'JOIN '.$table.$cond;
 
 		if ($this->qb_caching === TRUE)
 		{
@@ -405,7 +415,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function where($key, $value = NULL, $escape = TRUE)
+	public function where($key, $value = NULL, $escape = NULL)
 	{
 		return $this->_where($key, $value, 'AND ', $escape);
 	}
@@ -423,7 +433,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function or_where($key, $value = NULL, $escape = TRUE)
+	public function or_where($key, $value = NULL, $escape = NULL)
 	{
 		return $this->_where($key, $value, 'OR ', $escape);
 	}
@@ -443,23 +453,26 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
 	{
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
 		}
 
 		// If the escape value was not set will will base it on the global setting
-		$escape = $this->_protect_identifiers;
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0) ? '' : $type;
+			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+				? $this->_group_get_type('')
+				: $this->_group_get_type($type);
 
-			$k = $this->_has_operator($k)
-				? $this->protect_identifiers(substr($k, 0, strpos(rtrim($k), ' ')), FALSE, $escape).strchr(rtrim($k), ' ')
-				: $this->protect_identifiers($k, FALSE, $escape);
+			if ($escape === TRUE)
+			{
+				$k = (($op = $this->_get_operator($k)) !== FALSE)
+					? $this->escape_identifiers(trim(substr($k, 0, strpos($k, $op)))).' '.strstr($k, $op)
+					: $this->escape_identifiers(trim($k));
+			}
 
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
@@ -504,9 +517,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function where_in($key = NULL, $values = NULL)
+	public function where_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values);
+		return $this->_where_in($key, $values, FALSE, 'AND ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -521,9 +534,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function or_where_in($key = NULL, $values = NULL)
+	public function or_where_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values, FALSE, 'OR ');
+		return $this->_where_in($key, $values, FALSE, 'OR ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -538,9 +551,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function where_not_in($key = NULL, $values = NULL)
+	public function where_not_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values, TRUE);
+		return $this->_where_in($key, $values, TRUE, 'AND ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -555,9 +568,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function or_where_not_in($key = NULL, $values = NULL)
+	public function or_where_not_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values, TRUE, 'OR ');
+		return $this->_where_in($key, $values, TRUE, 'OR ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -573,20 +586,20 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	string
 	 * @return	object
 	 */
-	protected function _where_in($key = NULL, $values = NULL, $not = FALSE, $type = 'AND ')
+	protected function _where_in($key = NULL, $values = NULL, $not = FALSE, $type = 'AND ', $escape = NULL)
 	{
 		if ($key === NULL OR $values === NULL)
 		{
 			return $this;
 		}
 
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($values))
 		{
 			$values = array($values);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		$not = ($not) ? ' NOT' : '';
 
 		foreach ($values as $value)
@@ -594,8 +607,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$this->qb_wherein[] = $this->escape($value);
 		}
 
-		$prefix = (count($this->qb_where) === 0) ? '' : $type;
-		$this->qb_where[] = $where_in = $prefix.$this->protect_identifiers($key).$not.' IN ('.implode(', ', $this->qb_wherein).') ';
+		if ($escape === TRUE)
+		{
+			$key = $this->escape_identifiers(trim($key));
+		}
+
+		$prefix = (count($this->qb_where) === 0) ? $this->_group_get_type('') : $this->_group_get_type($type);
+		$this->qb_where[] = $where_in = $prefix.$key.$not.' IN ('.implode(', ', $this->qb_wherein).') ';
 
 		if ($this->qb_caching === TRUE)
 		{
@@ -690,8 +708,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $not = '')
 	{
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($field))
 		{
 			$field = array($field => $match);
@@ -700,7 +716,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		foreach ($field as $k => $v)
 		{
 			$k = $this->protect_identifiers($k);
-			$prefix = (count($this->qb_like) === 0) ? '' : $type;
+			$prefix = (count($this->qb_like) === 0) ? $this->_group_get_type('') : $this->_group_get_type($type);
 			$v = $this->escape_like_str($v);
 
 			if ($side === 'none')
@@ -886,7 +902,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function having($key, $value = '', $escape = TRUE)
+	public function having($key, $value = '', $escape = NULL)
 	{
 		return $this->_having($key, $value, 'AND ', $escape);
 	}
@@ -903,7 +919,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function or_having($key, $value = '', $escape = TRUE)
+	public function or_having($key, $value = '', $escape = NULL)
 	{
 		return $this->_having($key, $value, 'OR ', $escape);
 	}
@@ -921,21 +937,22 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	protected function _having($key, $value = '', $type = 'AND ', $escape = TRUE)
+	protected function _having($key, $value = '', $type = 'AND ', $escape = NULL)
 	{
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		foreach ($key as $k => $v)
 		{
 			$prefix = (count($this->qb_having) === 0) ? '' : $type;
 
-			if ($escape === TRUE)
-			{
-				$k = $this->protect_identifiers($k);
-			}
+			$k = $this->_has_operator($k)
+				? $this->protect_identifiers(substr($k, 0, strpos(rtrim($k), ' ')), FALSE, $escape).strchr(rtrim($k), ' ')
+				: $this->protect_identifiers($k, FALSE, $escape);
 
 			if ( ! $this->_has_operator($k))
 			{
@@ -968,7 +985,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool	enable field name escaping
 	 * @return	object
 	 */
-	public function order_by($orderby, $direction = '', $escape = TRUE)
+	public function order_by($orderby, $direction = '', $escape = NULL)
 	{
 		if (strtolower($direction) === 'random')
 		{
@@ -980,8 +997,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$direction = in_array(strtoupper(trim($direction)), array('ASC', 'DESC'), TRUE) ? ' '.$direction : ' ASC';
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
-		if ((strpos($orderby, ',') !== FALSE) && $escape === TRUE)
+		if ($escape === TRUE && strpos($orderby, ',') !== FALSE)
 		{
 			$temp = array();
 			foreach (explode(',', $orderby) as $part)
@@ -1028,12 +1046,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	public function limit($value, $offset = NULL)
 	{
-		$this->qb_limit = (int) $value;
-
-		if ( ! empty($offset))
-		{
-			$this->qb_offset = (int) $offset;
-		}
+		is_null($value) OR $this->qb_limit = (int) $value;
+		empty($offset) OR $this->qb_offset = (int) $offset;
 
 		return $this;
 	}
@@ -1048,21 +1062,40 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	public function offset($offset)
 	{
-		$this->qb_offset = (int) $offset;
+		empty($offset) OR $this->qb_offset = (int) $offset;
 		return $this;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * The "set" function.  Allows key/value pairs to be set for inserting or updating
+	 * Limit string
+	 *
+	 * Generates a platform-specific LIMIT clause
+	 *
+	 * @param	string	the sql query string
+	 * @param	int	the number of rows to limit the query to
+	 * @param	int	the offset value
+	 * @return	string
+	 */
+	protected function _limit($sql, $limit, $offset)
+	{
+		return $sql.' LIMIT '.($offset ? $offset.', ' : '').$limit;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * The "set" function.
+	 *
+	 * Allows key/value pairs to be set for inserting or updating
 	 *
 	 * @param	mixed
 	 * @param	string
 	 * @param	bool
 	 * @return	object
 	 */
-	public function set($key, $value = '', $escape = TRUE)
+	public function set($key, $value = '', $escape = NULL)
 	{
 		$key = $this->_object_to_array($key);
 
@@ -1071,16 +1104,12 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$key = array($key => $value);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		foreach ($key as $k => $v)
 		{
-			if ($escape === FALSE)
-			{
-				$this->qb_set[$this->protect_identifiers($k)] = $v;
-			}
-			else
-			{
-				$this->qb_set[$this->protect_identifiers($k, FALSE, TRUE)] = $this->escape($v);
-			}
+			$this->qb_set[$this->protect_identifiers($k, FALSE, $escape)] = ($escape)
+				? $this->escape($v) : $v;
 		}
 
 		return $this;
@@ -1189,7 +1218,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	string	the offset clause
 	 * @return	object
 	 */
-	public function get_where($table = '', $where = null, $limit = null, $offset = null)
+	public function get_where($table = '', $where = NULL, $limit = NULL, $offset = NULL)
 	{
 		if ($table !== '')
 		{
@@ -1286,7 +1315,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function set_insert_batch($key, $value = '', $escape = TRUE)
+	public function set_insert_batch($key, $value = '', $escape = NULL)
 	{
 		$key = $this->_object_to_array_batch($key);
 
@@ -1295,6 +1324,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$key = array($key => $value);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		$keys = array_keys($this->_object_to_array(current($key)));
 		sort($keys);
 
@@ -1326,7 +1357,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		foreach ($keys as $k)
 		{
-			$this->qb_keys[] = $this->protect_identifiers($k);
+			$this->qb_keys[] = $this->protect_identifiers($k, FALSE, $escape);
 		}
 
 		return $this;
@@ -1725,7 +1756,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function set_update_batch($key, $index = '', $escape = TRUE)
+	public function set_update_batch($key, $index = '', $escape = NULL)
 	{
 		$key = $this->_object_to_array_batch($key);
 
@@ -1734,6 +1765,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			// @todo error
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		foreach ($key as $k => $v)
 		{
 			$index_set = FALSE;
@@ -1745,7 +1778,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 					$index_set = TRUE;
 				}
 
-				$clean[$this->protect_identifiers($k2)] = ($escape === FALSE) ? $v2 : $this->escape($v2);
+				$clean[$this->protect_identifiers($k2, FALSE, $escape)] = ($escape === FALSE) ? $v2 : $this->escape($v2);
 			}
 
 			if ($index_set === FALSE)
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 6b67b7546..7496ee42f 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -437,23 +437,6 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * Generates a platform-specific LIMIT clause
-	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
-	 * @return	string
-	 */
-	protected function _limit($sql, $limit, $offset)
-	{
-		return $sql.'LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 5a03607ee..38d30962c 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -235,7 +235,7 @@ class CI_DB_interbase_driver extends CI_DB {
 	 * @param	int	$inc_by
 	 * @return	int
 	 */
-	public function insert_id($generator_name, $inc_by=0)
+	public function insert_id($generator_name, $inc_by = 0)
 	{
 		//If a generator hasn't been used before it will return 0
 		return ibase_gen_id('"'.$generator_name.'"', $inc_by);
@@ -257,7 +257,8 @@ class CI_DB_interbase_driver extends CI_DB {
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
-			return $sql.' AND "RDB$RELATION_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql.' AND "RDB$RELATION_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
 		return $sql;
@@ -275,7 +276,7 @@ class CI_DB_interbase_driver extends CI_DB {
 	 */
 	protected function _list_columns($table = '')
 	{
-		return 'SELECT "RDB$FIELD_NAME" FROM "RDB$RELATION_FIELDS" WHERE "RDB$RELATION_NAME" = \''.$this->escape_str($table)."'";
+		return 'SELECT "RDB$FIELD_NAME" FROM "RDB$RELATION_FIELDS" WHERE "RDB$RELATION_NAME" = '.$this->escape($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -290,10 +291,7 @@ class CI_DB_interbase_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		// Need to find a more efficient way to do this
-		// but Interbase/Firebird seems to lack the
-		// limit clause
-		return 'SELECT * FROM '.$table;
+		return $this->_limit('SELECT * FROM '.$this->protect_identifiers($table), 1, NULL);
 	}
 
 	// --------------------------------------------------------------------
@@ -361,7 +359,6 @@ class CI_DB_interbase_driver extends CI_DB {
 			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '');
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
@@ -421,12 +418,12 @@ class CI_DB_interbase_driver extends CI_DB {
 		if (stripos($this->version(), 'firebird') !== FALSE)
 		{
 			$select = 'FIRST '. (int) $limit
-				.($offset > 0 ? ' SKIP '. (int) $offset : '');
+				.($offset ? ' SKIP '. (int) $offset : '');
 		}
 		else
 		{
 			$select = 'ROWS '
-				.($offset > 0 ? (int) $offset.' TO '.($limit + $offset) : (int) $limit);
+				.($offset ? (int) $offset.' TO '.($limit + $offset) : (int) $limit);
 		}
 
 		return preg_replace('`SELECT`i', 'SELECT '.$select, $sql);
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 47dc55844..7634be2bb 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -124,7 +124,7 @@ class CI_DB_mssql_driver extends CI_DB {
 		// Determine how identifiers are escaped
 		$query = $this->query('SELECT CASE WHEN (@@OPTIONS | 256) = @@OPTIONS THEN 1 ELSE 0 END AS qi');
 		$query = $query->row_array();
-		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query->qi;
+		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
 		$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
 
 		return $conn_id;
@@ -288,7 +288,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 */
 	public function insert_id()
 	{
-		$query = (self::_parse_major_version($this->version()) > 7)
+		$query = version_compare($this->version(), '8', '>=')
 			? 'SELECT SCOPE_IDENTITY() AS last_id'
 			: 'SELECT @@IDENTITY AS last_id';
 
@@ -300,23 +300,6 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Parse major version
-	 *
-	 * Grabs the major version number from the
-	 * database server version string passed in.
-	 *
-	 * @param	string	$version
-	 * @return	int	major version number
-	 */
-	protected function _parse_major_version($version)
-	{
-		preg_match('/([0-9]+)\.([0-9]+)\.([0-9]+)/', $version, $ver_info);
-		return $ver_info[1]; // return the major version b/c that's all we're interested in.
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @return	string
@@ -338,16 +321,17 @@ class CI_DB_mssql_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";
+		$sql = 'SELECT '.$this->escape_identifiers('name')
+			.' FROM '.$this->escape_identifiers('sysobjects')
+			.' WHERE '.$this->escape_identifiers('type')." = 'U'";
 
-		// for future compatibility
 		if ($prefix_limit !== FALSE AND $this->dbprefix !== '')
 		{
-			//$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
-			return FALSE; // not currently supported
+			$sql .= ' AND '.$this->escape_identifiers('name')." LIKE '".$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
-		return $sql;
+		return $sql.' ORDER BY '.$this->escape_identifiers('name');
 	}
 
 	// --------------------------------------------------------------------
@@ -377,7 +361,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return 'SELECT TOP 1 * FROM '.$table;
+		return 'SELECT TOP 1 * FROM '.$this->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 8938d22b5..d11f015a6 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -64,6 +64,12 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	public $delete_hack = TRUE;
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array
+	 * @return	void
+	 */
 	public function __construct($params)
 	{
 		parent::__construct($params);
@@ -74,6 +80,8 @@ class CI_DB_mysql_driver extends CI_DB {
 		}
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
@@ -335,7 +343,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = 'SHOW TABLES FROM '.$this->_escape_char.$this->database.$this->_escape_char;
+		$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
@@ -355,7 +363,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	public function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
 		return 'SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE);
 	}
@@ -453,23 +461,6 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * Generates a platform-specific LIMIT clause
-	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
-	 * @return	string
-	 */
-	protected function _limit($sql, $limit, $offset)
-	{
-		return $sql.' LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/mysql/mysql_forge.php b/system/database/drivers/mysql/mysql_forge.php
index d22454d84..2ac75bad2 100644
--- a/system/database/drivers/mysql/mysql_forge.php
+++ b/system/database/drivers/mysql/mysql_forge.php
@@ -62,7 +62,7 @@ class CI_DB_mysql_forge extends CI_DB_forge {
 
 				$sql .= "\n\t".$this->db->escape_identifiers($field);
 
-				empty($attributes['NAME']) OR ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
+				empty($attributes['NAME']) OR $sql .= ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
 
 				if ( ! empty($attributes['TYPE']))
 				{
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index d3fb77a22..d1581bf1a 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -335,7 +335,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = 'SHOW TABLES FROM '.$this->_escape_char.$this->database.$this->_escape_char;
+		$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
@@ -455,24 +455,6 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * Generates a platform-specific LIMIT clause
-	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
-	 * @return	string
-	 */
-	protected function _limit($sql, $limit, $offset)
-	{
-		return $sql.' LIMIT '.$limit
-			.($offset > 0 ? ' OFFSET '.$offset : '');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index e78091614..67bb0403b 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -66,6 +66,8 @@ class CI_DB_oci8_driver extends CI_DB {
 	protected $_count_string = 'SELECT COUNT(1) AS ';
 	protected $_random_keyword = ' ASC'; // not currently supported
 
+	protected $_reserved_identifiers = array('*', 'rownum');
+
 	// Set "auto commit" by default
 	public $commit_mode = OCI_COMMIT_ON_SUCCESS;
 
@@ -464,11 +466,12 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = 'SELECT TABLE_NAME FROM ALL_TABLES';
+		$sql = 'SELECT "TABLE_NAME" FROM "ALL_TABLES"';
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
-			return $sql." WHERE TABLE_NAME LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql.' WHERE "TABLE_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
 		return $sql;
@@ -486,7 +489,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _list_columns($table = '')
 	{
-		return 'SELECT COLUMN_NAME FROM all_tab_columns WHERE table_name = \''.$table.'\'';
+		return 'SELECT "COLUMN_NAME" FROM "all_tab_columns" WHERE "TABLE_NAME" = '.$this->escape($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -501,7 +504,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return 'SELECT * FROM '.$table.' WHERE rownum = 1';
+		return 'SELECT * FROM '.$this->protect_identifiers($table).' WHERE rownum = 1';
 	}
 
 	// --------------------------------------------------------------------
@@ -634,7 +637,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	{
 		$this->limit_used = TRUE;
 		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($offset + $limit).')'
-			.($offset !== 0 ? ' WHERE rnum >= '.$offset : '');
+			.($offset ? ' WHERE rnum >= '.$offset : '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index 222c311c0..bd5759289 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -331,23 +331,6 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * Generates a platform-specific LIMIT clause
-	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
-	 * @return	string
-	 */
-	protected function _limit($sql, $limit, $offset)
-	{
-		return $sql.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index e25013a52..a3ad46900 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -599,19 +599,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	 */
 	protected function _limit($sql, $limit, $offset)
 	{
-		if ($this->pdodriver === 'cubrid' OR $this->pdodriver === 'sqlite')
+		if ($this->pdodriver === 'pgsql')
 		{
-			$offset = ($offset == 0) ? '' : $offset.', ';
-
-			return $sql.'LIMIT '.$offset.$limit;
+			return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
 		}
-		else
-		{
-			$sql .= 'LIMIT '.$limit;
-			$sql .= ($offset > 0) ? ' OFFSET '.$offset : '';
 
-			return $sql;
-		}
+		return $sql.' LIMIT '.($offset ? $offset.', ' : '').$limit;
 	}
 
 }
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index ad9ac9000..e73122bc7 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -399,11 +399,13 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'";
+		$sql = 'SELECT "table_name" FROM "information_schema"."tables" WHERE "table_schema" = \'public\'';
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
-			return $sql." AND table_name LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql.' AND "table_name" LIKE \''
+				.$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
 		return $sql;
@@ -421,7 +423,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	protected function _list_columns($table = '')
 	{
-		return "SELECT column_name FROM information_schema.columns WHERE table_name = '".$table."'";
+		return 'SELECT "column_name" FROM "information_schema"."columns" WHERE "table_name" = '.$this->escape($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -580,7 +582,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	protected function _limit($sql, $limit, $offset)
 	{
-		return $sql.' LIMIT '.$limit.($offset == 0 ? '' : ' OFFSET '.$offset);
+		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
 	}
 
 	// --------------------------------------------------------------------
@@ -593,31 +595,31 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * @param	mixed
 	 * @param	mixed
 	 * @param	string
+	 * @param	mixed
 	 * @return	object
-	 *
 	 */
 	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
 	{
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
 		}
 
 		// If the escape value was not set will will base it on the global setting
-		if ( ! is_bool($escape))
-		{
-			$escape = $this->_protect_identifiers;
-		}
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0) ? '' : $type;
+			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+				? $this->_group_get_type('')
+				: $this->_group_get_type($type);
 
-			$k = $this->_has_operator($k)
-				? $this->protect_identifiers(substr($k, 0, strpos(rtrim($k), ' ')), FALSE, $escape).strchr(rtrim($k), ' ')
-				: $this->protect_identifiers($k, FALSE, $escape);
+			if ($escape === TRUE)
+			{
+				$k = (($op = $this->_get_operator($k)) !== FALSE)
+					? $this->escape_identifiers(trim(substr($k, 0, strpos($k, $op)))).' '.strstr($k, $op)
+					: $this->escape_identifiers(trim($k));
+			}
 
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 3305f6030..87be7a54a 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -360,23 +360,6 @@ class CI_DB_sqlite_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * Generates a platform-specific LIMIT clause
-	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
-	 * @return	string
-	 */
-	protected function _limit($sql, $limit, $offset)
-	{
-		return $sql.'LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index bed61891b..1c6533f22 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -353,23 +353,6 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * Generates a platform-specific LIMIT clause
-	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
-	 * @return	string
-	 */
-	protected function _limit($sql, $limit, $offset)
-	{
-		return $sql.' LIMIT '.($offset ? $offset.',' : '').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 825c02452..4fdc4aae0 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -91,7 +91,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 		// Determine how identifiers are escaped
 		$query = $this->query('SELECT CASE WHEN (@@OPTIONS | 256) = @@OPTIONS THEN 1 ELSE 0 END AS qi');
 		$query = $query->row_array();
-		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query->qi;
+		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
 		$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
 
 		return $conn_id;
@@ -284,7 +284,17 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		return "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";
+		$sql = 'SELECT '.$this->escape_identifiers('name')
+			.' FROM '.$this->escape_identifiers('sysobjects')
+			.' WHERE '.$this->escape_identifiers('type')." = 'U'";
+
+		if ($prefix_limit === TRUE && $this->dbprefix !== '')
+		{
+			$sql .= ' AND '.$this->escape_identifiers('name')." LIKE '".$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_escape_like_str, $this->_escape_like_chr);
+		}
+
+		return $sql.' ORDER BY '.$this->escape_identifiers('name');
 	}
 
 	// --------------------------------------------------------------------
@@ -314,7 +324,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return 'SELECT TOP 1 * FROM '.$table;
+		return 'SELECT TOP 1 * FROM '.$this->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/helpers/date_helper.php b/system/helpers/date_helper.php
index d5036f645..fc790c585 100644
--- a/system/helpers/date_helper.php
+++ b/system/helpers/date_helper.php
@@ -93,8 +93,10 @@ if ( ! function_exists('mdate'))
 		{
 			return '';
 		}
-
-		$time = ($time === '') ? now() : $time;
+		elseif (empty($time))
+		{
+			$time = now();
+		}
 
 		$datestr = str_replace(
 			'%\\',
@@ -122,24 +124,19 @@ if ( ! function_exists('standard_date'))
 	function standard_date($fmt = 'DATE_RFC822', $time = '')
 	{
 		$formats = array(
-						'DATE_ATOM'		=>	'%Y-%m-%dT%H:%i:%s%O',
-						'DATE_COOKIE'	=>	'%l, %d-%M-%y %H:%i:%s UTC',
-						'DATE_ISO8601'	=>	'%Y-%m-%dT%H:%i:%s%O',
-						'DATE_RFC822'	=>	'%D, %d %M %y %H:%i:%s %O',
-						'DATE_RFC850'	=>	'%l, %d-%M-%y %H:%i:%s UTC',
-						'DATE_RFC1036'	=>	'%D, %d %M %y %H:%i:%s %O',
-						'DATE_RFC1123'	=>	'%D, %d %M %Y %H:%i:%s %O',
-						'DATE_RFC2822'	=>	'%D, %d %M %Y %H:%i:%s %O',
-						'DATE_RSS'		=>	'%D, %d %M %Y %H:%i:%s %O',
-						'DATE_W3C'		=>	'%Y-%m-%dT%H:%i:%s%O'
-						);
-
-		if ( ! isset($formats[$fmt]))
-		{
-			return FALSE;
-		}
-
-		return mdate($formats[$fmt], $time);
+				'DATE_ATOM'		=>	'%Y-%m-%dT%H:%i:%s%O',
+				'DATE_COOKIE'	=>	'%l, %d-%M-%y %H:%i:%s UTC',
+				'DATE_ISO8601'	=>	'%Y-%m-%dT%H:%i:%s%O',
+				'DATE_RFC822'	=>	'%D, %d %M %y %H:%i:%s %O',
+				'DATE_RFC850'	=>	'%l, %d-%M-%y %H:%i:%s UTC',
+				'DATE_RFC1036'	=>	'%D, %d %M %y %H:%i:%s %O',
+				'DATE_RFC1123'	=>	'%D, %d %M %Y %H:%i:%s %O',
+				'DATE_RFC2822'	=>	'%D, %d %M %Y %H:%i:%s %O',
+				'DATE_RSS'		=>	'%D, %d %M %Y %H:%i:%s %O',
+				'DATE_W3C'		=>	'%Y-%m-%dT%H:%i:%s%O'
+				);
+
+		return isset($formats[$fmt]) ? mdate($formats[$fmt], $time) : FALSE;
 	}
 }
 
@@ -163,20 +160,9 @@ if ( ! function_exists('timespan'))
 		$CI =& get_instance();
 		$CI->lang->load('date');
 
-		if ( ! is_numeric($seconds))
-		{
-			$seconds = 1;
-		}
-
-		if ( ! is_numeric($time))
-		{
-			$time = time();
-		}
-
-		if ( ! is_numeric($units))
-		{
-			$units = 7;
-		}
+		is_numeric($seconds) OR $seconds = 1;
+		is_numeric($time) OR $time = time();
+		is_numeric($units) OR $units = 7;
 
 		$seconds = ($time <= $seconds) ? 1 : $time - $seconds;
 
@@ -185,7 +171,7 @@ if ( ! function_exists('timespan'))
 
 		if ($years > 0)
 		{
-			$str[] = $years.' '.$CI->lang->line((($years	> 1) ? 'date_years' : 'date_year'));
+			$str[] = $years.' '.$CI->lang->line($years > 1 ? 'date_years' : 'date_year');
 		}
 
 		$seconds -= $years * 31557600;
@@ -195,7 +181,7 @@ if ( ! function_exists('timespan'))
 		{
 			if ($months > 0)
 			{
-				$str[] = $months.' '.$CI->lang->line((($months	> 1) ? 'date_months' : 'date_month'));
+				$str[] = $months.' '.$CI->lang->line($months > 1 ? 'date_months' : 'date_month');
 			}
 
 			$seconds -= $months * 2629743;
@@ -207,7 +193,7 @@ if ( ! function_exists('timespan'))
 		{
 			if ($weeks > 0)
 			{
-				$str[] = $weeks.' '.$CI->lang->line((($weeks	> 1) ? 'date_weeks' : 'date_week'));
+				$str[] = $weeks.' '.$CI->lang->line($weeks > 1 ? 'date_weeks' : 'date_week');
 			}
 
 			$seconds -= $weeks * 604800;
@@ -219,7 +205,7 @@ if ( ! function_exists('timespan'))
 		{
 			if ($days > 0)
 			{
-				$str[] = $days.' '.$CI->lang->line((($days	> 1) ? 'date_days' : 'date_day'));
+				$str[] = $days.' '.$CI->lang->line($days > 1 ? 'date_days' : 'date_day');
 			}
 
 			$seconds -= $days * 86400;
@@ -231,7 +217,7 @@ if ( ! function_exists('timespan'))
 		{
 			if ($hours > 0)
 			{
-				$str[] = $hours.' '.$CI->lang->line((($hours	> 1) ? 'date_hours' : 'date_hour'));
+				$str[] = $hours.' '.$CI->lang->line($hours > 1 ? 'date_hours' : 'date_hour');
 			}
 
 			$seconds -= $hours * 3600;
@@ -243,7 +229,7 @@ if ( ! function_exists('timespan'))
 		{
 			if ($minutes > 0)
 			{
-				$str[] = $minutes.' '.$CI->lang->line((($minutes	> 1) ? 'date_minutes' : 'date_minute'));
+				$str[] = $minutes.' '.$CI->lang->line($minutes > 1 ? 'date_minutes' : 'date_minute');
 			}
 
 			$seconds -= $minutes * 60;
@@ -251,7 +237,7 @@ if ( ! function_exists('timespan'))
 
 		if (count($str) === 0)
 		{
-			$str[] = $seconds.' '.$CI->lang->line((($seconds	> 1) ? 'date_seconds' : 'date_second'));
+			$str[] = $seconds.' '.$CI->lang->line($seconds > 1 ? 'date_seconds' : 'date_second');
 		}
 
 		return implode(', ', $str);
@@ -278,12 +264,16 @@ if ( ! function_exists('days_in_month'))
 		{
 			return 0;
 		}
-
-		if ( ! is_numeric($year) OR strlen($year) !== 4)
+		elseif ( ! is_numeric($year) OR strlen($year) !== 4)
 		{
 			$year = date('Y');
 		}
 
+		if ($year >= 1970)
+		{
+			return (int) date('t', mktime(12, 0, 0, $month, 1, $year));
+		}
+
 		if ($month == 2)
 		{
 			if ($year % 400 === 0 OR ($year % 4 === 0 && $year % 100 !== 0))
@@ -314,13 +304,13 @@ if ( ! function_exists('local_to_gmt'))
 			$time = time();
 		}
 
-		return gmmktime(
-			date('H', $time),
-			date('i', $time),
-			date('s', $time),
-			date('m', $time),
-			date('d', $time),
-			date('Y', $time)
+		return mktime(
+			gmdate('G', $time),
+			gmdate('i', $time),
+			gmdate('s', $time),
+			gmdate('n', $time),
+			gmdate('j', $time),
+			gmdate('Y', $time)
 		);
 	}
 }
@@ -350,12 +340,7 @@ if ( ! function_exists('gmt_to_local'))
 
 		$time += timezones($timezone) * 3600;
 
-		if ($dst === TRUE)
-		{
-			$time += 3600;
-		}
-
-		return $time;
+		return ($dst === TRUE) ? $time + 3600 : $time;
 	}
 }
 
@@ -405,7 +390,7 @@ if ( ! function_exists('unix_to_human'))
 	 */
 	function unix_to_human($time = '', $seconds = FALSE, $fmt = 'us')
 	{
-		$r  = date('Y', $time).'-'.date('m', $time).'-'.date('d', $time).' ';
+		$r = date('Y', $time).'-'.date('m', $time).'-'.date('d', $time).' ';
 
 		if ($fmt === 'us')
 		{
@@ -423,7 +408,7 @@ if ( ! function_exists('unix_to_human'))
 
 		if ($fmt === 'us')
 		{
-			$r .= ' '.date('A', $time);
+			return $r.' '.date('A', $time);
 		}
 
 		return $r;
@@ -451,51 +436,33 @@ if ( ! function_exists('human_to_unix'))
 
 		$datestr = preg_replace('/\040+/', ' ', trim($datestr));
 
-		if ( ! preg_match('/^[0-9]{2,4}\-[0-9]{1,2}\-[0-9]{1,2}\s[0-9]{1,2}:[0-9]{1,2}(?::[0-9]{1,2})?(?:\s[AP]M)?$/i', $datestr))
+		if ( ! preg_match('/^(\d{2}|\d{4})\-[0-9]{1,2}\-[0-9]{1,2}\s[0-9]{1,2}:[0-9]{1,2}(?::[0-9]{1,2})?(?:\s[AP]M)?$/i', $datestr))
 		{
 			return FALSE;
 		}
 
 		$split = explode(' ', $datestr);
 
-		$ex = explode('-', $split['0']);
-
-		$year  = (strlen($ex[0]) === 2) ? '20'.$ex[0] : $ex[0];
-		$month = (strlen($ex[1]) === 1) ? '0'.$ex[1]  : $ex[1];
-		$day   = (strlen($ex[2]) === 1) ? '0'.$ex[2]  : $ex[2];
+		list($year, $month, $day) = explode('-', $split[0]);
 
 		$ex = explode(':', $split['1']);
 
-		$hour = (strlen($ex[0]) === 1) ? '0'.$ex[0] : $ex[0];
-		$min  = (strlen($ex[1]) === 1) ? '0'.$ex[1] : $ex[1];
-
-		if (isset($ex[2]) && preg_match('/[0-9]{1,2}/', $ex[2]))
-		{
-			$sec = (strlen($ex[2]) === 1) ? '0'.$ex[2] : $ex[2];
-		}
-		else
-		{
-			// Unless specified, seconds get set to zero.
-			$sec = '00';
-		}
+		$hour	= (int) $ex[0];
+		$min	= (int) $ex[1];
+		$sec	= ( ! empty($ex[2]) && preg_match('/[0-9]{1,2}/', $ex[2]))
+				? (int) $ex[2] : 0;
 
 		if (isset($split[2]))
 		{
 			$ampm = strtolower($split[2]);
 
-			if (substr($ampm, 0, 1) === 'p' && $hour < 12)
+			if ($ampm[0] === 'p' && $hour < 12)
 			{
 				$hour += 12;
 			}
-
-			if (substr($ampm, 0, 1) === 'a' && $hour == 12)
-			{
-				$hour =  '00';
-			}
-
-			if (strlen($hour) === 1)
+			elseif ($ampm[0] === 'a' && $hour === 12)
 			{
-				$hour = '0'.$hour;
+				$hour = 0;
 			}
 		}
 
@@ -521,9 +488,13 @@ if ( ! function_exists('nice_date'))
 		{
 			return 'Unknown';
 		}
+		elseif (empty($format))
+		{
+			$format = 'U';
+		}
 
 		// Date like: YYYYMM
-		if (preg_match('/^\d{6}$/', $bad_date))
+		if (preg_match('/^\d{6}$/i', $bad_date))
 		{
 			if (in_array(substr($bad_date, 0, 2), array('19', '20')))
 			{
@@ -540,20 +511,15 @@ if ( ! function_exists('nice_date'))
 		}
 
 		// Date Like: YYYYMMDD
-		if (preg_match('/^\d{8}$/', $bad_date))
+		if (preg_match('/^(\d{2})\d{2}(\d{4})$/i', $bad_date, $matches))
 		{
-			$month = substr($bad_date, 0, 2);
-			$day   = substr($bad_date, 2, 2);
-			$year  = substr($bad_date, 4, 4);
-
-			return date($format, strtotime($month.'/01/'.$year));
+			return date($format, strtotime($matches[1].'/01/'.$matches[2]));
 		}
 
 		// Date Like: MM-DD-YYYY __or__ M-D-YYYY (or anything in between)
-		if (preg_match('/^\d{1,2}-\d{1,2}-\d{4}$/', $bad_date))
+		if (preg_match('/^(\d{1,2})-(\d{1,2})-(\d{4})$/i', $bad_date, $matches))
 		{
-			list($m, $d, $y) = explode('-', $bad_date);
-			return date($format, strtotime($y.'-'.$m.'-'.$d));
+			return date($format, strtotime($matches[3].'-'.$matches[1].'-'.$matches[2]));
 		}
 
 		// Any other kind of string, when converted into UNIX time,
@@ -581,9 +547,10 @@ if ( ! function_exists('timezone_menu'))
 	 * @param	string	timezone
 	 * @param	string	classname
 	 * @param	string	menu name
+	 * @param	mixed	attributes
 	 * @return	string
 	 */
-	function timezone_menu($default = 'UTC', $class = '', $name = 'timezones')
+	function timezone_menu($default = 'UTC', $class = '', $name = 'timezones', $attributes = '')
 	{
 		$CI =& get_instance();
 		$CI->lang->load('date');
@@ -597,7 +564,22 @@ if ( ! function_exists('timezone_menu'))
 			$menu .= ' class="'.$class.'"';
 		}
 
-		$menu .= ">\n";
+		// Generate a string from the attributes submitted, if any
+		if (is_array($attributes))
+		{
+			$atts = '';
+			foreach ($attributes as $key => $val)
+			{
+				$atts .= ' '.$key.'="'.$val.'"';
+			}
+			$attributes = $atts;
+		}
+		elseif (is_string($attributes) && strlen($attributes) > 0)
+		{
+			$attributes = ' '.$attributes;
+		}
+
+		$menu .= $attributes.">\n";
 
 		foreach (timezones() as $key => $val)
 		{
@@ -675,8 +657,6 @@ if ( ! function_exists('timezones'))
 			return $zones;
 		}
 
-		$tz = ($tz === 'GMT') ? 'UTC' : $tz;
-
 		return isset($zones[$tz]) ? $zones[$tz] : 0;
 	}
 }
diff --git a/system/helpers/download_helper.php b/system/helpers/download_helper.php
index 5efbc4930..09c4de578 100644
--- a/system/helpers/download_helper.php
+++ b/system/helpers/download_helper.php
@@ -46,7 +46,7 @@ if ( ! function_exists('force_download'))
 	 *
 	 * @param	string	filename
 	 * @param	mixed	the data to be downloaded
-	 * @param	bool	wether to try and send the actual file MIME type
+	 * @param	bool	whether to try and send the actual file MIME type
 	 * @return	void
 	 */
 	function force_download($filename = '', $data = '', $set_mime = FALSE)
diff --git a/system/helpers/file_helper.php b/system/helpers/file_helper.php
index be616f62d..7270ee32c 100644
--- a/system/helpers/file_helper.php
+++ b/system/helpers/file_helper.php
@@ -47,6 +47,7 @@ if ( ! function_exists('read_file'))
 	 * This function is DEPRECATED and should be removed in
 	 * CodeIgniter 3.1+. Use file_get_contents() instead.
 	 *
+	 * @deprecated
 	 * @param	string	path to file
 	 * @return	string
 	 */
diff --git a/system/helpers/form_helper.php b/system/helpers/form_helper.php
index 984634315..0c5d55037 100644
--- a/system/helpers/form_helper.php
+++ b/system/helpers/form_helper.php
@@ -62,9 +62,11 @@ if ( ! function_exists('form_open'))
 		{
 			$action = $CI->config->site_url($action);
 		}
-
-		// If no action is provided then set to the current url
-		$action OR $action = $CI->config->site_url($CI->uri->uri_string());
+		elseif ( ! $action)
+		{
+			// If no action is provided then set to the current url
+			$action = $CI->config->site_url($CI->uri->uri_string());
+		}
 
 		$form = '<form action="'.$action.'"'._attributes_to_string($attributes, TRUE).">\n";
 
@@ -76,7 +78,7 @@ if ( ! function_exists('form_open'))
 
 		if (is_array($hidden) && count($hidden) > 0)
 		{
-			$form .= sprintf('<div style="display:none;">%s</div>', form_hidden($hidden));
+			$form .= '<div style="display:none;">'.form_hidden($hidden).'</div>';
 		}
 
 		return $form;
diff --git a/system/helpers/security_helper.php b/system/helpers/security_helper.php
index 3e6e91435..0e8e9f93d 100644
--- a/system/helpers/security_helper.php
+++ b/system/helpers/security_helper.php
@@ -80,6 +80,7 @@ if ( ! function_exists('do_hash'))
 	 * This function is DEPRECATED and should be removed in
 	 * CodeIgniter 3.1+. Use hash() instead.
 	 *
+	 * @deprecated
 	 * @param	string
 	 * @param	string
 	 * @return	string
@@ -107,7 +108,8 @@ if ( ! function_exists('strip_image_tags'))
 	 */
 	function strip_image_tags($str)
 	{
-		return preg_replace(array('#<img\s+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img\s+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
+		$CI =& get_instance();
+		return $CI->security->strip_image_tags($str);
 	}
 }
 
@@ -123,7 +125,7 @@ if ( ! function_exists('encode_php_tags'))
 	 */
 	function encode_php_tags($str)
 	{
-		return str_replace(array('<?php', '<?PHP', '<?', '?>'),  array('&lt;?php', '&lt;?PHP', '&lt;?', '?&gt;'), $str);
+		return str_replace(array('<?', '?>'),  array('&lt;?', '?&gt;'), $str);
 	}
 }
 
diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 2bd41b04d..39e6343a6 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -199,26 +199,33 @@ if ( ! function_exists('anchor_popup'))
 
 		if ($attributes === FALSE)
 		{
-			return '<a href="javascript:void(0);" onclick="window.open(\''.$site_url."', '_blank');\">".$title.'</a>';
+			return '<a href="'.$site_url.'" onclick="window.open(\''.$site_url."', '_blank'); return false;\">".$title.'</a>';
 		}
 
 		if ( ! is_array($attributes))
 		{
-			$attributes = array();
+			$attributes = array($attributes);
+
+			// Ref: http://www.w3schools.com/jsref/met_win_open.asp
+			$window_name = '_blank';
+		}
+		elseif ( ! empty($attributes['window_name']))
+		{
+			$window_name = $attributes['window_name'];
+			unset($attributes['window_name']);
 		}
 
-		foreach (array('width' => '800', 'height' => '600', 'scrollbars' => 'yes', 'status' => 'yes', 'resizable' => 'yes', 'screenx' => '0', 'screeny' => '0', ) as $key => $val)
+		foreach (array('width' => '800', 'height' => '600', 'scrollbars' => 'yes', 'status' => 'yes', 'resizable' => 'yes', 'screenx' => '0', 'screeny' => '0') as $key => $val)
 		{
 			$atts[$key] = isset($attributes[$key]) ? $attributes[$key] : $val;
 			unset($attributes[$key]);
 		}
 
-		if ($attributes !== '')
-		{
-			$attributes = _parse_attributes($attributes);
-		}
+		$attributes = empty($attributes) ? '' : _parse_attributes($attributes);
 
-		return '<a href="javascript:void(0);" onclick="window.open(\''.$site_url."', '_blank', '"._parse_attributes($atts, TRUE)."');\"".$attributes.'>'.$title.'</a>';
+		return '<a href="'.$site_url
+			.'" onclick="window.open(\''.$site_url."', '".$window_name."', '"._parse_attributes($atts, TRUE)."'); return false;\""
+			.$attributes.'>'.$title.'</a>';
 	}
 }
 
@@ -519,7 +526,7 @@ if ( ! function_exists('redirect'))
 	 * @param	int
 	 * @return	string
 	 */
-	function redirect($uri = '', $method = 'auto', $http_response_code = 302)
+	function redirect($uri = '', $method = 'auto', $code = NULL)
 	{
 		if ( ! preg_match('#^https?://#i', $uri))
 		{
@@ -531,14 +538,22 @@ if ( ! function_exists('redirect'))
 		{
 			$method = 'refresh';
 		}
+		elseif ($method !== 'refresh' && (empty($code) OR ! is_numeric($code)))
+		{
+			// Reference: http://en.wikipedia.org/wiki/Post/Redirect/Get
+			$code = (isset($_SERVER['REQUEST_METHOD'], $_SERVER['SERVER_PROTOCOL'])
+					&& $_SERVER['REQUEST_METHOD'] === 'POST'
+					&& $_SERVER['SERVER_PROTOCOL'] === 'HTTP/1.1')
+				? 303 : 302;
+		}
 
-		switch($method)
+		switch ($method)
 		{
 			case 'refresh':
 				header('Refresh:0;url='.$uri);
 				break;
 			default:
-				header('Location: '.$uri, TRUE, $http_response_code);
+				header('Location: '.$uri, TRUE, $code);
 				break;
 		}
 		exit;
diff --git a/system/language/english/migration_lang.php b/system/language/english/migration_lang.php
index 9e3e18807..af920660c 100644
--- a/system/language/english/migration_lang.php
+++ b/system/language/english/migration_lang.php
@@ -26,7 +26,7 @@
  */
 
 $lang['migration_none_found']			= "No migrations were found.";
-$lang['migration_not_found']			= "This migration could not be found.";
+$lang['migration_not_found']			= "No migration could be found with the version number: %d.";
 $lang['migration_multiple_version']		= "This are multiple migrations with the same version number: %d.";
 $lang['migration_class_doesnt_exist']	= "The migration class \"%s\" could not be found.";
 $lang['migration_missing_up_method']	= "The migration class \"%s\" is missing an 'up' method.";
diff --git a/system/libraries/Cache/drivers/Cache_file.php b/system/libraries/Cache/drivers/Cache_file.php
index 08231963e..37d77c268 100644
--- a/system/libraries/Cache/drivers/Cache_file.php
+++ b/system/libraries/Cache/drivers/Cache_file.php
@@ -73,7 +73,7 @@ class CI_Cache_file extends CI_Driver {
 
 		$data = unserialize(file_get_contents($this->_cache_path.$id));
 
-		if (time() >  $data['time'] + $data['ttl'])
+		if ($data['ttl'] > 0 && time() >  $data['time'] + $data['ttl'])
 		{
 			unlink($this->_cache_path.$id);
 			return FALSE;
diff --git a/system/libraries/Calendar.php b/system/libraries/Calendar.php
index 969a7610a..a49f171b9 100644
--- a/system/libraries/Calendar.php
+++ b/system/libraries/Calendar.php
@@ -155,7 +155,7 @@ class CI_Calendar {
 	public function generate($year = '', $month = '', $data = array())
 	{
 		// Set and validate the supplied month/year
-		if ($year === '')
+		if (empty($year))
 		{
 			$year  = date('Y', $this->local_time);
 		}
@@ -168,7 +168,7 @@ class CI_Calendar {
 			$year = '20'.$year;
 		}
 
-		if ($month === '')
+		if (empty($month))
 		{
 			$month = date('m', $this->local_time);
 		}
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 09f217530..dd5477e05 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -247,7 +247,7 @@ class CI_Email {
 			$name = $replyto;
 		}
 
-		if (strncmp($name, '"', 1) !== 0)
+		if (strpos($name, '"') !== 0)
 		{
 			$name = '"'.$name.'"';
 		}
@@ -606,7 +606,7 @@ class CI_Email {
 
 		foreach ($this->_base_charsets as $charset)
 		{
-			if (strncmp($charset, $this->charset, strlen($charset)) === 0)
+			if (strpos($charset, $this->charset) === 0)
 			{
 				$this->_encoding = '7bit';
 			}
@@ -651,7 +651,7 @@ class CI_Email {
 	protected function _set_date()
 	{
 		$timezone = date('Z');
-		$operator = (strncmp($timezone, '-', 1) === 0) ? '-' : '+';
+		$operator = ($timezone[0] === '-') ? '-' : '+';
 		$timezone = abs($timezone);
 		$timezone = floor($timezone/3600) * 100 + ($timezone % 3600) / 60;
 
@@ -1481,7 +1481,7 @@ class CI_Email {
 
 		$this->_set_error_message($reply);
 
-		if (strncmp($reply, '250', 3) !== 0)
+		if (strpos($reply, '250') !== 0)
 		{
 			$this->_set_error_message('lang:email_smtp_error', $reply);
 			return FALSE;
@@ -1637,7 +1637,7 @@ class CI_Email {
 
 		$reply = $this->_get_smtp_data();
 
-		if (strncmp($reply, '334', 3) !== 0)
+		if (strpos($reply, '334') !== 0)
 		{
 			$this->_set_error_message('lang:email_failed_smtp_login', $reply);
 			return FALSE;
@@ -1647,7 +1647,7 @@ class CI_Email {
 
 		$reply = $this->_get_smtp_data();
 
-		if (strncmp($reply, '334', 3) !== 0)
+		if (strpos($reply, '334') !== 0)
 		{
 			$this->_set_error_message('lang:email_smtp_auth_un', $reply);
 			return FALSE;
@@ -1657,7 +1657,7 @@ class CI_Email {
 
 		$reply = $this->_get_smtp_data();
 
-		if (strncmp($reply, '235', 3) !== 0)
+		if (strpos($reply, '235') !== 0)
 		{
 			$this->_set_error_message('lang:email_smtp_auth_pw', $reply);
 			return FALSE;
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 6cbe032c7..8e03e91f3 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -571,8 +571,7 @@ class CI_Form_validation {
 		{
 			foreach ($postdata as $key => $val)
 			{
-				$this->_execute($row, $rules, $val, $cycles);
-				$cycles++;
+				$this->_execute($row, $rules, $val, $key);
 			}
 
 			return;
@@ -649,7 +648,12 @@ class CI_Form_validation {
 			}
 			else
 			{
-				$postdata = $this->_field_data[$row['field']]['postdata'];
+				// If we get an array field, but it's not expected - then it is most likely
+				// somebody messing with the form on the client side, so we'll just consider
+				// it an empty field
+				$postdata = is_array($this->_field_data[$row['field']]['postdata'])
+						? NULL
+						: $this->_field_data[$row['field']]['postdata'];
 			}
 
 			// Is the rule a callback?
@@ -993,15 +997,19 @@ class CI_Form_validation {
 	 * Minimum Length
 	 *
 	 * @param	string
-	 * @param	int
+	 * @param	string
 	 * @return	bool
 	 */
 	public function min_length($str, $val)
 	{
-		if (preg_match('/[^0-9]/', $val))
+		if ( ! is_numeric($val))
 		{
 			return FALSE;
 		}
+		else
+		{
+			$val = (int) $val;
+		}
 
 		return (MB_ENABLED === TRUE)
 			? ($val <= mb_strlen($str))
@@ -1014,15 +1022,19 @@ class CI_Form_validation {
 	 * Max Length
 	 *
 	 * @param	string
-	 * @param	int
+	 * @param	string
 	 * @return	bool
 	 */
 	public function max_length($str, $val)
 	{
-		if (preg_match('/[^0-9]/', $val))
+		if ( ! is_numeric($val))
 		{
 			return FALSE;
 		}
+		else
+		{
+			$val = (int) $val;
+		}
 
 		return (MB_ENABLED === TRUE)
 			? ($val >= mb_strlen($str))
@@ -1035,15 +1047,19 @@ class CI_Form_validation {
 	 * Exact Length
 	 *
 	 * @param	string
-	 * @param	int
+	 * @param	string
 	 * @return	bool
 	 */
 	public function exact_length($str, $val)
 	{
-		if (preg_match('/[^0-9]/', $val))
+		if ( ! is_numeric($val))
 		{
 			return FALSE;
 		}
+		else
+		{
+			$val = (int) $val;
+		}
 
 		return (MB_ENABLED === TRUE)
 			? (mb_strlen($str) === $val)
@@ -1113,7 +1129,7 @@ class CI_Form_validation {
 	 */
 	public function alpha($str)
 	{
-		return (bool) preg_match('/^[a-z]+$/i', $str);
+		return ctype_alpha($str);
 	}
 
 	// --------------------------------------------------------------------
@@ -1126,7 +1142,7 @@ class CI_Form_validation {
 	 */
 	public function alpha_numeric($str)
 	{
-		return (bool) preg_match('/^[a-z0-9]+$/i', $str);
+		return ctype_alnum((string) $str);
 	}
 
 	// --------------------------------------------------------------------
@@ -1248,7 +1264,7 @@ class CI_Form_validation {
 	 */
 	public function is_natural($str)
 	{
-		return (bool) preg_match('/^[0-9]+$/', $str);
+		return ctype_digit((string) $str);
 	}
 
 	// --------------------------------------------------------------------
@@ -1261,7 +1277,7 @@ class CI_Form_validation {
 	 */
 	public function is_natural_no_zero($str)
 	{
-		return ($str !== 0 && preg_match('/^[0-9]+$/', $str));
+		return ($str != 0 && ctype_digit((string) $str));
 	}
 
 	// --------------------------------------------------------------------
@@ -1344,7 +1360,7 @@ class CI_Form_validation {
 	 */
 	public function strip_image_tags($str)
 	{
-		return $this->CI->input->strip_image_tags($str);
+		return $this->CI->security->strip_image_tags($str);
 	}
 
 	// --------------------------------------------------------------------
@@ -1370,7 +1386,7 @@ class CI_Form_validation {
 	 */
 	public function encode_php_tags($str)
 	{
-		return str_replace(array('<?php', '<?PHP', '<?', '?>'),  array('&lt;?php', '&lt;?PHP', '&lt;?', '?&gt;'), $str);
+		return str_replace(array('<?', '?>'),  array('&lt;?', '?&gt;'), $str);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/libraries/Ftp.php b/system/libraries/Ftp.php
index 461e884fb..76f5e151a 100644
--- a/system/libraries/Ftp.php
+++ b/system/libraries/Ftp.php
@@ -445,7 +445,7 @@ class CI_FTP {
 	 * Set file permissions
 	 *
 	 * @param	string	the file path
-	 * @param	string	the permissions
+	 * @param	int	the permissions
 	 * @return	bool
 	 */
 	public function chmod($path, $perm)
diff --git a/system/libraries/Javascript.php b/system/libraries/Javascript.php
index 98fec61d3..5c8b09217 100644
--- a/system/libraries/Javascript.php
+++ b/system/libraries/Javascript.php
@@ -620,7 +620,7 @@ class CI_Javascript {
 			$this->_javascript_location = $this->CI->config->item('javascript_location');
 		}
 
-		if ($relative === TRUE OR strncmp($external_file, 'http://', 7) === 0 OR strncmp($external_file, 'https://', 8) === 0)
+		if ($relative === TRUE OR strpos($external_file, 'http://') === 0 OR strpos($external_file, 'https://') === 0)
 		{
 			$str = $this->_open_script($external_file);
 		}
diff --git a/system/libraries/Migration.php b/system/libraries/Migration.php
index 4391b235d..3a1e7a0ad 100644
--- a/system/libraries/Migration.php
+++ b/system/libraries/Migration.php
@@ -179,7 +179,7 @@ class CI_Migration {
 
 		// We now prepare to actually DO the migrations
 		// But first let's make sure that everything is the way it should be
-		for ($i = $start; $i !== $stop; $i += $step)
+		for ($i = $start; $i != $stop; $i += $step)
 		{
 			$f = glob(sprintf($this->_migration_path.'%03d_*.php', $i));
 
diff --git a/system/libraries/Pagination.php b/system/libraries/Pagination.php
index cdec736ff..75745dd48 100644
--- a/system/libraries/Pagination.php
+++ b/system/libraries/Pagination.php
@@ -36,39 +36,40 @@
  */
 class CI_Pagination {
 
-	public $base_url				= ''; // The page we are linking to
-	public $prefix				= ''; // A custom prefix added to the path.
-	public $suffix				= ''; // A custom suffix added to the path.
-	public $total_rows			= 0; // Total number of items (database results)
-	public $per_page				= 10; // Max number of items you want shown per page
-	public $num_links			= 2; // Number of "digit" links to show before/after the currently viewed page
-	public $cur_page				= 0; // The current page being viewed
-	public $use_page_numbers		= FALSE; // Use page number for segment instead of offset
-	public $first_link			= '&lsaquo; First';
-	public $next_link			= '&gt;';
-	public $prev_link			= '&lt;';
-	public $last_link			= 'Last &rsaquo;';
-	public $uri_segment			= 3;
-	public $full_tag_open		= '';
-	public $full_tag_close		= '';
-	public $first_tag_open		= '';
-	public $first_tag_close		= '&nbsp;';
-	public $last_tag_open		= '&nbsp;';
-	public $last_tag_close		= '';
-	public $first_url			= ''; // Alternative URL for the First Page.
-	public $cur_tag_open			= '&nbsp;<strong>';
-	public $cur_tag_close		= '</strong>';
-	public $next_tag_open		= '&nbsp;';
-	public $next_tag_close		= '&nbsp;';
-	public $prev_tag_open		= '&nbsp;';
-	public $prev_tag_close		= '';
-	public $num_tag_open			= '&nbsp;';
-	public $num_tag_close		= '';
-	public $page_query_string	= FALSE;
-	public $query_string_segment = 'per_page';
-	public $display_pages		= TRUE;
-	public $anchor_class			= '';
-	public $attr_rel			= TRUE;
+	protected $base_url				= ''; // The page we are linking to
+	protected $prefix				= ''; // A custom prefix added to the path.
+	protected $suffix				= ''; // A custom suffix added to the path.
+	protected $total_rows			= 0; // Total number of items (database results)
+	protected $per_page				= 10; // Max number of items you want shown per page
+	protected $num_links			= 2; // Number of "digit" links to show before/after the currently viewed page
+	protected $cur_page				= 0; // The current page being viewed
+	protected $use_page_numbers		= FALSE; // Use page number for segment instead of offset
+	protected $first_link			= '&lsaquo; First';
+	protected $next_link			= '&gt;';
+	protected $prev_link			= '&lt;';
+	protected $last_link			= 'Last &rsaquo;';
+	protected $uri_segment			= 3;
+	protected $full_tag_open		= '';
+	protected $full_tag_close		= '';
+	protected $first_tag_open		= '';
+	protected $first_tag_close		= '&nbsp;';
+	protected $last_tag_open		= '&nbsp;';
+	protected $last_tag_close		= '';
+	protected $first_url			= ''; // Alternative URL for the First Page.
+	protected $cur_tag_open			= '&nbsp;<strong>';
+	protected $cur_tag_close		= '</strong>';
+	protected $next_tag_open		= '&nbsp;';
+	protected $next_tag_close		= '&nbsp;';
+	protected $prev_tag_open		= '&nbsp;';
+	protected $prev_tag_close		= '';
+	protected $num_tag_open			= '&nbsp;';
+	protected $num_tag_close		= '';
+	protected $page_query_string	= FALSE;
+	protected $query_string_segment 	= 'per_page';
+	protected $display_pages		= TRUE;
+	protected $_attributes			= '';
+	protected $_link_types			= array();
+	protected $reuse_query_string   = FALSE;
 
 	/**
 	 * Constructor
@@ -92,15 +93,29 @@ class CI_Pagination {
 	 */
 	public function initialize($params = array())
 	{
+		$attributes = array();
+
+		if (isset($params['attributes']) && is_array($params['attributes']))
+		{
+			$attributes = $params['attributes'];
+			unset($params['attributes']);
+		}
+
+		// Deprecated legacy support for the anchor_class option
+		// Should be removed in CI 3.1+
+		if (isset($params['anchor_class']))
+		{
+			empty($params['anchor_class']) OR $attributes['class'] = $params['anchor_class'];
+			unset($params['anchor_class']);
+		}
+
+		$this->_parse_attributes($attributes);
+
 		if (count($params) > 0)
 		{
 			foreach ($params as $key => $val)
 			{
-				if ($key === 'anchor_class')
-				{
-					$this->anchor_class = ($val) ? 'class="'.$val.'" ' : '';
-				}
-				elseif (isset($this->$key))
+				if (isset($this->$key))
 				{
 					$this->$key = $val;
 				}
@@ -208,29 +223,46 @@ class CI_Pagination {
 
 		// And here we go...
 		$output = '';
+		$query_string = '';
+
+		// Add anything in the query string back to the links
+		// Note: Nothing to do with query_string_segment or any other query string options
+		if ($this->reuse_query_string === TRUE)
+		{
+			$get = $CI->input->get();
+			
+			// Unset the controll, method, old-school routing options
+			unset($get['c'], $get['m'], $get[$this->query_string_segment]);
+
+			// Put everything else onto the end
+			$query_string = (strpos($this->base_url, '&amp;') !== FALSE ? '&amp;' : '?') . http_build_query($get, '', '&amp;');
+
+			// Add this after the suffix to put it into more links easily
+			$this->suffix .= $query_string;
+		}
 
 		// Render the "First" link
 		if ($this->first_link !== FALSE && $this->cur_page > ($this->num_links + 1))
 		{
 			$first_url = ($this->first_url === '') ? $this->base_url : $this->first_url;
-			$output .= $this->first_tag_open.'<a '.$this->anchor_class.'href="'.$first_url.'"'.$this->_attr_rel('start').'>'
+			$output .= $this->first_tag_open.'<a href="'.$first_url.'"'.$this->_attributes.$this->_attr_rel('start').'>'
 				.$this->first_link.'</a>'.$this->first_tag_close;
 		}
 
 		// Render the "previous" link
-		if  ($this->prev_link !== FALSE && $this->cur_page !== 1)
+		if ($this->prev_link !== FALSE && $this->cur_page !== 1)
 		{
 			$i = ($this->use_page_numbers) ? $uri_page_number - 1 : $uri_page_number - $this->per_page;
 
 			if ($i === $base_page && $this->first_url !== '')
 			{
-				$output .= $this->prev_tag_open.'<a '.$this->anchor_class.'href="'.$this->first_url.'"'.$this->_attr_rel('prev').'>'
+				$output .= $this->prev_tag_open.'<a href="'.$this->first_url.$query_string.'"'.$this->_attributes.$this->_attr_rel('prev').'>'
 					.$this->prev_link.'</a>'.$this->prev_tag_close;
 			}
 			else
 			{
-				$i = ($i === $base_page) ? '' : $this->prefix.$i.$this->suffix;
-				$output .= $this->prev_tag_open.'<a '.$this->anchor_class.'href="'.$this->base_url.$i.'"'.$this->_attr_rel('prev').'>'
+				$append = ($i === $base_page) ? $query_string : $this->prefix.$i.$this->suffix;
+				$output .= $this->prev_tag_open.'<a href="'.$this->base_url.$append.'"'.$this->_attributes.$this->_attr_rel('prev').'>'
 					.$this->prev_link.'</a>'.$this->prev_tag_close;
 			}
 
@@ -243,7 +275,6 @@ class CI_Pagination {
 			for ($loop = $start -1; $loop <= $end; $loop++)
 			{
 				$i = ($this->use_page_numbers) ? $loop : ($loop * $this->per_page) - $this->per_page;
-
 				if ($i >= $base_page)
 				{
 					if ($this->cur_page === $loop)
@@ -253,17 +284,15 @@ class CI_Pagination {
 					else
 					{
 						$n = ($i === $base_page) ? '' : $i;
-
-						if ($n === '' && $this->first_url !== '')
+						if ($n === '' && ! empty($this->first_url))
 						{
-							$output .= $this->num_tag_open.'<a '.$this->anchor_class.'href="'.$this->first_url.'"'.$this->_attr_rel('start').'>'
+							$output .= $this->num_tag_open.'<a href="'.$this->first_url.$query_string.'"'.$this->_attributes.$this->_attr_rel('start').'>'
 								.$loop.'</a>'.$this->num_tag_close;
 						}
 						else
 						{
-							$n = ($n === '') ? '' : $this->prefix.$n.$this->suffix;
-
-							$output .= $this->num_tag_open.'<a '.$this->anchor_class.'href="'.$this->base_url.$n.'"'.$this->_attr_rel().'>'
+							$append = ($n === '') ? $query_string : $this->prefix.$n.$this->suffix;
+							$output .= $this->num_tag_open.'<a href="'.$this->base_url.$append.'"'.$this->_attributes.$this->_attr_rel('start').'>'
 								.$loop.'</a>'.$this->num_tag_close;
 						}
 					}
@@ -276,8 +305,8 @@ class CI_Pagination {
 		{
 			$i = ($this->use_page_numbers) ? $this->cur_page + 1 : $this->cur_page * $this->per_page;
 
-			$output .= $this->next_tag_open.'<a '.$this->anchor_class.'href="'.$this->base_url.$this->prefix.$i.$this->suffix.'"'.$this->_attr_rel('next').'>'
-				.$this->next_link.'</a>'.$this->next_tag_close;
+			$output .= $this->next_tag_open.'<a href="'.$this->base_url.$this->prefix.$i.$this->suffix.'"'.$this->_attributes
+				.$this->_attr_rel('next').'>'.$this->next_link.'</a>'.$this->next_tag_close;
 		}
 
 		// Render the "Last" link
@@ -285,7 +314,7 @@ class CI_Pagination {
 		{
 			$i = ($this->use_page_numbers) ? $num_pages : ($num_pages * $this->per_page) - $this->per_page;
 
-			$output .= $this->last_tag_open.'<a '.$this->anchor_class.'href="'.$this->base_url.$this->prefix.$i.$this->suffix.'"'.$this->_attr_rel().'>'
+			$output .= $this->last_tag_open.'<a href="'.$this->base_url.$this->prefix.$i.$this->suffix.'"'.$this->_attributes.'>'
 				.$this->last_link.'</a>'.$this->last_tag_close;
 		}
 
@@ -300,23 +329,44 @@ class CI_Pagination {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Parse attributes
+	 *
+	 * @param	array
+	 * @return	void
+	 */
+	protected function _parse_attributes($attributes)
+	{
+		isset($attributes['rel']) OR $attributes['rel'] = TRUE;
+		$this->_link_types = ($attributes['rel'])
+					? array('start' => 'start', 'prev' => 'prev', 'next' => 'next')
+					: array();
+		unset($attributes['rel']);
+
+		$this->_attributes = '';
+		foreach ($attributes as $key => $value)
+		{
+			$this->_attributes .= ' '.$key.'="'.$value.'"';
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Add "rel" attribute
 	 *
+	 * @link	http://www.w3.org/TR/html5/links.html#linkTypes
 	 * @param	string
 	 * @return	string
 	 */
-	protected function _attr_rel($value = '')
+	protected function _attr_rel($type)
 	{
-		if (empty($this->attr_rel) OR ($this->attr_rel === TRUE && empty($value)))
-		{
-			return '';
-		}
-		elseif ( ! is_bool($this->attr_rel))
+		if (isset($this->_link_types[$type]))
 		{
-			$value = $this->attr_rel;
+			unset($this->_link_types[$type]);
+			return ' rel="'.$type.'"';
 		}
 
-		return ' rel="'.$value.'"';
+		return '';
 	}
 
 }
diff --git a/system/libraries/Profiler.php b/system/libraries/Profiler.php
index d96088c14..1e961f6df 100644
--- a/system/libraries/Profiler.php
+++ b/system/libraries/Profiler.php
@@ -116,6 +116,12 @@ class CI_Profiler {
 	 */
 	public function set_sections($config)
 	{
+		if (isset($config['query_toggle_count']))
+		{
+			$this->_query_toggle_count = (int) $config['query_toggle_count'];
+			unset($config['query_toggle_count']);
+		}
+
 		foreach ($config as $method => $enable)
 		{
 			if (in_array($method, $this->_available_sections))
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index c96daaf15..d381440cd 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -59,6 +59,7 @@ class CI_Upload {
 	public $error_msg		= array();
 	public $mimes			= array();
 	public $remove_spaces		= TRUE;
+	public $detect_mime		= TRUE;
 	public $xss_clean		= FALSE;
 	public $temp_prefix		= 'temp_file_';
 	public $client_name		= '';
@@ -116,6 +117,7 @@ class CI_Upload {
 					'image_size_str'		=> '',
 					'error_msg'			=> array(),
 					'remove_spaces'			=> TRUE,
+					'detect_mime'			=> TRUE,
 					'xss_clean'			=> FALSE,
 					'temp_prefix'			=> 'temp_file_',
 					'client_name'			=> ''
@@ -209,7 +211,13 @@ class CI_Upload {
 		// Set the uploaded data as class variables
 		$this->file_temp = $_FILES[$field]['tmp_name'];
 		$this->file_size = $_FILES[$field]['size'];
-		$this->_file_mime_type($_FILES[$field]);
+
+		// Skip MIME type detection?
+		if ($this->detect_mime !== FALSE)
+		{
+			$this->_file_mime_type($_FILES[$field]);
+		}
+
 		$this->file_type = preg_replace('/^(.+?);.*$/', '\\1', $this->file_type);
 		$this->file_type = strtolower(trim(stripslashes($this->file_type), '"'));
 		$this->file_name = $this->_prep_filename($_FILES[$field]['name']);
@@ -990,7 +998,7 @@ class CI_Upload {
 		 */
 		if (function_exists('finfo_file'))
 		{
-			$finfo = finfo_open(FILEINFO_MIME);
+			$finfo = @finfo_open(FILEINFO_MIME);
 			if (is_resource($finfo)) // It is possible that a FALSE value is returned, if there is no magic MIME database file found on the system
 			{
 				$mime = @finfo_file($finfo, $file['tmp_name']);
@@ -1021,7 +1029,9 @@ class CI_Upload {
 		 */
 		if (DIRECTORY_SEPARATOR !== '\\')
 		{
-			$cmd = 'file --brief --mime '.escapeshellarg($file['tmp_name']).' 2>&1';
+			$cmd = function_exists('escapeshellarg')
+				? 'file --brief --mime '.escapeshellarg($file['tmp_name']).' 2>&1'
+				: 'file --brief --mime '.$file['tmp_name'].' 2>&1';
 
 			if (function_exists('exec'))
 			{
diff --git a/system/libraries/Xmlrpc.php b/system/libraries/Xmlrpc.php
index 6f3542333..eac4ac118 100644
--- a/system/libraries/Xmlrpc.php
+++ b/system/libraries/Xmlrpc.php
@@ -778,7 +778,7 @@ class XML_RPC_Message extends CI_Xmlrpc
 		}
 
 		// Check for HTTP 200 Response
-		if (strncmp($data, 'HTTP', 4) === 0 && ! preg_match('/^HTTP\/[0-9\.]+ 200 /', $data))
+		if (strpos($data, 'HTTP') === 0 && ! preg_match('/^HTTP\/[0-9\.]+ 200 /', $data))
 		{
 			$errstr = substr($data, 0, strpos($data, "\n")-1);
 			return new XML_RPC_Response(0, $this->xmlrpcerr['http_error'], $this->xmlrpcstr['http_error'].' ('.$errstr.')');
diff --git a/system/libraries/Xmlrpcs.php b/system/libraries/Xmlrpcs.php
index be930b0f9..e81f2ca9a 100644
--- a/system/libraries/Xmlrpcs.php
+++ b/system/libraries/Xmlrpcs.php
@@ -303,7 +303,7 @@ class CI_Xmlrpcs extends CI_Xmlrpc
 		$methName = $m->method_name;
 
 		// Check to see if it is a system call
-		$system_call = (strncmp($methName, 'system', 5) === 0);
+		$system_call = (strpos($methName, 'system') === 0);
 
 		if ($this->xss_clean === FALSE)
 		{
diff --git a/system/libraries/Zip.php b/system/libraries/Zip.php
index e0dc637ad..5c4c257f8 100644
--- a/system/libraries/Zip.php
+++ b/system/libraries/Zip.php
@@ -40,7 +40,7 @@
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/libraries/zip.html
  */
-class CI_Zip  {
+class CI_Zip {
 
 	/**
 	 * Zip data in string form