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

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

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

4 files changed, 305 insertions, 232 deletions

diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index c2fccc1f7..5af44371c 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,12 +24,13 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Database Adapter Class
  *
  * Note: _DB is an extender class that the app controller
- * creates dynamically based on whether the active record
+ * creates dynamically based on whether the query builder
  * class is being used or not.
  *
  * @package		CodeIgniter
@@ -40,48 +41,78 @@
  */
 class CI_DB_mysql_driver extends CI_DB {
 
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
 	public $dbdriver = 'mysql';
 
-	// The character used for escaping
-	protected $_escape_char = '`';
-
-	// clause and character used for LIKE escape sequences - not used in MySQL
-	protected $_like_escape_str = '';
-	protected $_like_escape_chr = '';
-
 	/**
-	 * The syntax to count rows is slightly different across different
-	 * database engines, so this string appears in each driver and is
-	 * used for the count_all() and count_all_results() functions.
+	 * Compression flag
+	 *
+	 * @var	bool
 	 */
-	protected $_count_string = 'SELECT COUNT(*) AS ';
-	protected $_random_keyword = ' RAND()'; // database specific random keyword
+	public $compress = FALSE;
 
 	/**
+	 * DELETE hack flag
+	 *
 	 * Whether to use the MySQL "delete hack" which allows the number
 	 * of affected rows to be shown. Uses a preg_replace when enabled,
 	 * adding a bit more processing to all queries.
+	 *
+	 * @var	bool
 	 */
 	public $delete_hack = TRUE;
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Identifier escape character
+	 *
+	 * @var	string
+	 */
+	protected $_escape_char = '`';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	array	$params
+	 * @return	void
+	 */
 	public function __construct($params)
 	{
 		parent::__construct($params);
 
-		if ($this->port != '')
+		if ( ! empty($this->port))
 		{
 			$this->hostname .= ':'.$this->port;
 		}
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
+	 * @param	bool	$persistent
 	 * @return	resource
 	 */
-	public function db_connect()
+	public function db_connect($persistent = FALSE)
 	{
-		return @mysql_connect($this->hostname, $this->username, $this->password, TRUE);
+		$client_flags = ($this->compress === FALSE) ? 0 : MYSQL_CLIENT_COMPRESS;
+
+		if ($this->encrypt === TRUE)
+		{
+			$client_flags = $client_flags | MYSQL_CLIENT_SSL;
+		}
+
+		return ($persistent === TRUE)
+			? @mysql_pconnect($this->hostname, $this->username, $this->password, $client_flags)
+			: @mysql_connect($this->hostname, $this->username, $this->password, TRUE, $client_flags);
 	}
 
 	// --------------------------------------------------------------------
@@ -93,7 +124,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	public function db_pconnect()
 	{
-		return @mysql_pconnect($this->hostname, $this->username, $this->password);
+		return $this->db_connect(TRUE);
 	}
 
 	// --------------------------------------------------------------------
@@ -119,7 +150,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Select the database
 	 *
-	 * @param	string	database name
+	 * @param	string	$database
 	 * @return	bool
 	 */
 	public function db_select($database = '')
@@ -143,7 +174,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Set client character set
 	 *
-	 * @param	string
+	 * @param	string	$charset
 	 * @return	bool
 	 */
 	protected function _db_set_charset($charset)
@@ -160,9 +191,21 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	public function version()
 	{
-		return isset($this->data_cache['version'])
-			? $this->data_cache['version']
-			: $this->data_cache['version'] = @mysql_get_server_info($this->conn_id);
+		if (isset($this->data_cache['version']))
+		{
+			return $this->data_cache['version'];
+		}
+		elseif ( ! $this->conn_id)
+		{
+			$this->initialize();
+		}
+
+		if ( ! $this->conn_id OR ($version = @mysql_get_server_info($this->conn_id)) === FALSE)
+		{
+			return FALSE;
+		}
+
+		return $this->data_cache['version'] = $version;
 	}
 
 	// --------------------------------------------------------------------
@@ -170,7 +213,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	mixed
 	 */
 	protected function _execute($sql)
@@ -185,7 +228,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * If needed, each database adapter can prep the query string
 	 *
-	 * @param	string	an SQL query
+	 * @param	string	$sql	an SQL query
 	 * @return	string
 	 */
 	protected function _prep_query($sql)
@@ -205,6 +248,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
+	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
@@ -270,8 +314,8 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @param	string	$str
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	public function escape_str($str, $like = FALSE)
@@ -279,19 +323,21 @@ class CI_DB_mysql_driver extends CI_DB {
 		if (is_array($str))
 		{
 			foreach ($str as $key => $val)
-	   		{
+			{
 				$str[$key] = $this->escape_str($val, $like);
-	   		}
+			}
 
-	   		return $str;
-	   	}
+			return $str;
+		}
 
 		$str = is_resource($this->conn_id) ? mysql_real_escape_string($str, $this->conn_id) : addslashes($str);
 
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
-			return str_replace(array('%', '_'), array('\\%', '\\_'), $str);
+			return str_replace(array($this->_like_escape_chr, '%', '_'),
+						array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
+						$str);
 		}
 
 		return $str;
@@ -324,47 +370,18 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * "Count All" query
-	 *
-	 * Generates a platform-specific query string that counts all records in
-	 * the specified database
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function count_all($table = '')
-	{
-		if ($table == '')
-		{
-			return 0;
-		}
-
-		$query = $this->query($this->_count_string.$this->protect_identifiers('numrows').' FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE));
-		if ($query->num_rows() == 0)
-		{
-			return 0;
-		}
-
-		$query = $query->row();
-		$this->_reset_select();
-		return (int) $query->numrows;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * List table query
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @param	bool
+	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($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 && $this->dbprefix != '')
+		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
 			return $sql." LIKE '".$this->escape_like_str($this->dbprefix)."%'";
 		}
@@ -379,10 +396,10 @@ class CI_DB_mysql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
-	public function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
 		return 'SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE);
 	}
@@ -392,29 +409,34 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Returns an object with field data
 	 *
-	 * @param	string	the table name
-	 * @return	object
+	 * @param	string	$table
+	 * @return	array
 	 */
 	public function field_data($table = '')
 	{
-		if ($table == '')
+		if ($table === '')
 		{
 			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
 		}
 
-		$query = $this->query('DESCRIBE '.$this->protect_identifiers($table, TRUE, NULL, FALSE));
+		if (($query = $this->query('SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE))) === FALSE)
+		{
+			return FALSE;
+		}
 		$query = $query->result_object();
 
 		$retval = array();
 		for ($i = 0, $c = count($query); $i < $c; $i++)
 		{
-			preg_match('/([a-z]+)(\(\d+\))?/', $query[$i]->Type, $matches);
-
 			$retval[$i]			= new stdClass();
 			$retval[$i]->name		= $query[$i]->Field;
-			$retval[$i]->type		= empty($matches[1]) ? NULL : $matches[1];
+
+			sscanf($query[$i]->Type, '%[a-z](%d)',
+				$retval[$i]->type,
+				$retval[$i]->max_length
+			);
+
 			$retval[$i]->default		= $query[$i]->Default;
-			$retval[$i]->max_length		= empty($matches[2]) ? NULL : preg_replace('/[^\d]/', '', $matches[2]);
 			$retval[$i]->primary_key	= (int) ($query[$i]->Key === 'PRI');
 		}
 
@@ -439,37 +461,16 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
-	 *
-	 * @param	string	table name
-	 * @return	string
-	 */
-	protected function _from_tables($tables)
-	{
-		if ( ! is_array($tables))
-		{
-			$tables = array($tables);
-		}
-
-		return '('.implode(', ', $tables).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update_Batch statement
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
+	 * @param	string	$table	Table name
+	 * @param	array	$values	Update data
+	 * @param	string	$index	WHERE key
 	 * @return	string
 	 */
-	protected function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index)
 	{
 		$ids = array();
 		foreach ($values as $key => $val)
@@ -478,9 +479,9 @@ class CI_DB_mysql_driver extends CI_DB {
 
 			foreach (array_keys($val) as $field)
 			{
-				if ($field != $index)
+				if ($field !== $index)
 				{
-					$final[$field][] =  'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
+					$final[$field][] = 'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
 				}
 			}
 		}
@@ -493,26 +494,29 @@ class CI_DB_mysql_driver extends CI_DB {
 				.'ELSE '.$k.' END, ';
 		}
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
-			.' WHERE '.(($where != '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
-			.$index.' IN('.implode(',', $ids).')';
+		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
+
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * FROM tables
 	 *
-	 * Generates a platform-specific LIMIT clause
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
 	 *
-	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _from_tables()
 	{
-		return $sql.' LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
+		if ( ! empty($this->qb_join) && count($this->qb_from) > 1)
+		{
+			return '('.implode(', ', $this->qb_from).')';
+		}
+
+		return implode(', ', $this->qb_from);
 	}
 
 	// --------------------------------------------------------------------
@@ -520,12 +524,11 @@ class CI_DB_mysql_driver extends CI_DB {
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@mysql_close($conn_id);
+		@mysql_close($this->conn_id);
 	}
 
 }
diff --git a/system/database/drivers/mysql/mysql_forge.php b/system/database/drivers/mysql/mysql_forge.php
index 0e39affa7..f4394c685 100644
--- a/system/database/drivers/mysql/mysql_forge.php
+++ b/system/database/drivers/mysql/mysql_forge.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Forge Class
@@ -34,151 +35,178 @@
  */
 class CI_DB_mysql_forge extends CI_DB_forge {
 
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var	string
+	 */
 	protected $_create_database	= 'CREATE DATABASE %s CHARACTER SET %s COLLATE %s';
 
 	/**
-	 * Process Fields
+	 * CREATE TABLE keys flag
 	 *
-	 * @param	mixed	the fields
-	 * @return	string
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var	bool
 	 */
-	protected function _process_fields($fields)
-	{
-		$current_field_count = 0;
-		$sql = '';
-
-		foreach ($fields as $field => $attributes)
-		{
-			// Numeric field names aren't allowed in databases, so if the key is
-			// numeric, we know it was assigned by PHP and the developer manually
-			// entered the field information, so we'll simply add it to the list
-			if (is_numeric($field))
-			{
-				$sql .= "\n\t".$attributes;
-			}
-			else
-			{
-				$attributes = array_change_key_case($attributes, CASE_UPPER);
-
-				$sql .= "\n\t".$this->db->protect_identifiers($field)
-					.( ! empty($attributes['NAME']) ? ' '.$this->db->protect_identifiers($attributes['NAME']).' ' : '');
+	protected $_create_table_keys	= TRUE;
 
-				if ( ! empty($attributes['TYPE']))
-				{
-					$sql .=  ' '.$attributes['TYPE'];
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var	array
+	 */
+	protected $_unsigned		= array(
+		'TINYINT',
+		'SMALLINT',
+		'MEDIUMINT',
+		'INT',
+		'INTEGER',
+		'BIGINT',
+		'REAL',
+		'DOUBLE',
+		'DOUBLE PRECISION',
+		'FLOAT',
+		'DECIMAL',
+		'NUMERIC'
+	);
 
-					if ( ! empty($attributes['CONSTRAINT']))
-					{
-						switch (strtolower($attributes['TYPE']))
-						{
-							case 'decimal':
-							case 'float':
-							case 'numeric':
-								$sql .= '('.implode(',', $attributes['CONSTRAINT']).')';
-								break;
-							case 'enum':
-							case 'set':
-								$sql .= '("'.implode('","', $attributes['CONSTRAINT']).'")';
-								break;
-							default:
-								$sql .= '('.$attributes['CONSTRAINT'].')';
-						}
-					}
-				}
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var	string
+	 */
+	protected $_null		= 'NULL';
 
-				$sql .= (( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE) ? ' UNSIGNED' : '')
-					.(isset($attributes['DEFAULT']) ? " DEFAULT '".$attributes['DEFAULT']."'" : '')
-					.(( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE) ? ' NULL' : ' NOT NULL')
-					.(( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE) ? ' AUTO_INCREMENT' : '');
-			}
+	// --------------------------------------------------------------------
 
-			// don't add a comma on the end of the last field
-			if (++$current_field_count < count($fields))
-			{
-				$sql .= ',';
-			}
-		}
+	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$db	Database object
+	 * @return	void
+	 */
+	public function __construct(&$db)
+	{
+		parent::__construct($db);
 
-		return $sql;
+		$this->_create_table .= ' DEFAULT CHARSET '.$this->db->char_set.' COLLATE '.$this->db->dbcollat;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Create Table
+	 * ALTER TABLE
 	 *
-	 * @param	string	the table name
-	 * @param	mixed	the fields
-	 * @param	mixed	primary key(s)
-	 * @param	mixed	key(s)
-	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @param	string	$alter_type	ALTER type
+	 * @param	string	$table		Table name
+	 * @param	mixed	$field		Column definition
+	 * @return	string|string[]
 	 */
-	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _alter_table($alter_type, $table, $field)
 	{
-		$sql = 'CREATE TABLE ';
-
-		if ($if_not_exists === TRUE)
-		{
-			$sql .= 'IF NOT EXISTS ';
-		}
-
-		$sql .= $this->db->protect_identifiers($table).' ('.$this->_process_fields($fields);
-
-		if (count($primary_keys) > 0)
+		if ($alter_type === 'DROP')
 		{
-			$key_name = $this->db->protect_identifiers(implode('_', $primary_keys));
-			$sql .= ",\n\tPRIMARY KEY ".$key_name.' ('.implode(', ', $this->db->protect_identifiers($primary_keys)).')';
+			return parent::_alter_table($alter_type, $table, $field);
 		}
 
-		if (is_array($keys) && count($keys) > 0)
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
+		for ($i = 0, $c = count($field); $i < $c; $i++)
 		{
-			foreach ($keys as $key)
+			if ($field[$i]['_literal'] !== FALSE)
 			{
-				if (is_array($key))
+				$field[$i] = ($alter_type === 'ADD')
+						? "\n\tADD ".$field[$i]['_literal']
+						: "\n\tMODIFY ".$field[$i]['_literal'];
+			}
+			else
+			{
+				if ($alter_type === 'ADD')
 				{
-					$key_name = $this->db->protect_identifiers(implode('_', $key));
-					$key = $this->db->protect_identifiers($key);
+					$field[$i]['_literal'] = "\n\tADD ";
 				}
 				else
 				{
-					$key_name = $this->db->protect_identifiers($key);
-					$key = array($key_name);
+					$field[$i]['_literal'] = empty($field[$i]['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
 				}
 
-				$sql .= ",\n\tKEY ".$key_name.' ('.implode(', ', $key).')';
+				$field[$i] = $field[$i]['_literal'].$this->_process_column($field[$i]);
 			}
 		}
 
-		return $sql."\n) DEFAULT CHARACTER SET ".$this->db->char_set.' COLLATE '.$this->db->dbcollat.';';
+		return array($sql.implode(',', $field));
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Alter table query
+	 * Process column
 	 *
-	 * Generates a platform-specific query so that a table can be altered
-	 * Called by add_column(), drop_column() and column_alter()
+	 * @param	array	$field
+	 * @return	string
+	 */
+	protected function _process_column($field)
+	{
+		$extra_clause = isset($field['after'])
+			? ' AFTER '.$this->db->escape_identifiers($field['after']) : '';
+
+		if (empty($extra_clause) && isset($field['first']) && $field['first'] === TRUE)
+		{
+			$extra_clause = ' FIRST';
+		}
+
+		return $this->db->escape_identifiers($field['name'])
+			.(empty($field['new_name']) ? '' : ' '.$this->db->escape_identifiers($field['new_name']))
+			.' '.$field['type'].$field['length']
+			.$field['unsigned']
+			.$field['null']
+			.$field['default']
+			.$field['auto_increment']
+			.$field['unique']
+			.$extra_clause;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Process indexes
 	 *
-	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
-	 * @param	string	the column name
-	 * @param	array	fields
-	 * @param	string	the field after which we should add the new field
+	 * @param	string	$table	(ignored)
 	 * @return	string
 	 */
-	protected function _alter_table($alter_type, $table, $fields, $after_field = '')
+	protected function _process_indexes($table)
 	{
-		$sql = 'ALTER TABLE '.$this->db->protect_identifiers($table).' '.$alter_type.' ';
+		$sql = '';
 
-		// DROP has everything it needs now.
-		if ($alter_type === 'DROP')
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
 		{
-			return $sql.$this->db->protect_identifiers($fields);
+			if (is_array($this->keys[$i]))
+			{
+				for ($i2 = 0, $c2 = count($this->keys[$i]); $i2 < $c2; $i2++)
+				{
+					if ( ! isset($this->fields[$this->keys[$i][$i2]]))
+					{
+						unset($this->keys[$i][$i2]);
+						continue;
+					}
+				}
+			}
+			elseif ( ! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) OR $this->keys[$i] = array($this->keys[$i]);
+
+			$sql .= ",\n\tKEY ".$this->db->escape_identifiers(implode('_', $this->keys[$i]))
+				.' ('.implode(', ', $this->db->escape_identifiers($this->keys[$i])).')';
 		}
 
-		return $sql.$this->_process_fields($fields)
-			.($after_field != '' ? ' AFTER '.$this->db->protect_identifiers($after_field) : '');
+		$this->keys = array();
+
+		return $sql;
 	}
 
 }
diff --git a/system/database/drivers/mysql/mysql_result.php b/system/database/drivers/mysql/mysql_result.php
index 14d6d072a..293980e97 100644
--- a/system/database/drivers/mysql/mysql_result.php
+++ b/system/database/drivers/mysql/mysql_result.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Result Class
@@ -33,17 +34,35 @@
  * @category	Database
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/database/
+ * @since	1.0
  */
 class CI_DB_mysql_result extends CI_DB_result {
 
 	/**
+	 * Class constructor
+	 *
+	 * @param	object	&$driver_object
+	 * @return	void
+	 */
+	public function __construct(&$driver_object)
+	{
+		parent::__construct($driver_object);
+
+		// Required, due to mysql_data_seek() causing nightmares
+		// with empty result sets
+		$this->num_rows = @mysql_num_rows($this->result_id);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Number of rows in the result set
 	 *
 	 * @return	int
 	 */
 	public function num_rows()
 	{
-		return @mysql_num_rows($this->result_id);
+		return $this->num_rows;
 	}
 
 	// --------------------------------------------------------------------
@@ -96,8 +115,7 @@ class CI_DB_mysql_result extends CI_DB_result {
 			$retval[$i]->name		= mysql_field_name($this->result_id, $i);
 			$retval[$i]->type		= mysql_field_type($this->result_id, $i);
 			$retval[$i]->max_length		= mysql_field_len($this->result_id, $i);
-			$retval[$i]->primary_key	= (strpos(mysql_field_flags($this->result_id, $i), 'primary_key') === FALSE) ? 0 : 1;
-			$retval[$i]->default		= '';
+			$retval[$i]->primary_key	= (int) (strpos(mysql_field_flags($this->result_id, $i), 'primary_key') !== FALSE);
 		}
 
 		return $retval;
@@ -126,13 +144,16 @@ class CI_DB_mysql_result extends CI_DB_result {
 	 *
 	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
+	 * @param	int	$n
 	 * @return	bool
 	 */
-	protected function _data_seek($n = 0)
+	public function data_seek($n = 0)
 	{
-		return mysql_data_seek($this->result_id, $n);
+		return $this->num_rows
+			? @mysql_data_seek($this->result_id, $n)
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -156,11 +177,12 @@ class CI_DB_mysql_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
+	 * @param	string	$class_name
 	 * @return	object
 	 */
-	protected function _fetch_object()
+	protected function _fetch_object($class_name = 'stdClass')
 	{
-		return mysql_fetch_object($this->result_id);
+		return mysql_fetch_object($this->result_id, $class_name);
 	}
 
 }
diff --git a/system/database/drivers/mysql/mysql_utility.php b/system/database/drivers/mysql/mysql_utility.php
index 642323dbd..8aa051755 100644
--- a/system/database/drivers/mysql/mysql_utility.php
+++ b/system/database/drivers/mysql/mysql_utility.php
@@ -1,4 +1,4 @@
-<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
@@ -24,6 +24,7 @@
  * @since		Version 1.0
  * @filesource
  */
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * MySQL Utility Class
@@ -34,14 +35,33 @@
  */
 class CI_DB_mysql_utility extends CI_DB_utility {
 
+	/**
+	 * List databases statement
+	 *
+	 * @var	string
+	 */
 	protected $_list_databases	= 'SHOW DATABASES';
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_optimize_table	= 'OPTIMIZE TABLE %s';
+
+	/**
+	 * REPAIR TABLE statement
+	 *
+	 * @var	string
+	 */
 	protected $_repair_table	= 'REPAIR TABLE %s';
 
+	// --------------------------------------------------------------------
+
 	/**
-	 * MySQL Export
+	 * Export
 	 *
-	 * @param	array	Preferences
+	 * @param	array	$params	Preferences
 	 * @return	mixed
 	 */
 	protected function _backup($params = array())
@@ -65,7 +85,7 @@ class CI_DB_mysql_utility extends CI_DB_utility {
 			}
 
 			// Get the table schema
-			$query = $this->db->query('SHOW CREATE TABLE '.$this->db->protect_identifiers($this->db->database).'.'.$this->db->protect_identifiers($table));
+			$query = $this->db->query('SHOW CREATE TABLE '.$this->db->escape_identifiers($this->db->database.'.'.$table));
 
 			// No result means the table name was invalid
 			if ($query === FALSE)
@@ -76,7 +96,7 @@ class CI_DB_mysql_utility extends CI_DB_utility {
 			// Write out the table schema
 			$output .= '#'.$newline.'# TABLE STRUCTURE FOR: '.$table.$newline.'#'.$newline.$newline;
 
-			if ($add_drop == TRUE)
+			if ($add_drop === TRUE)
 			{
 				$output .= 'DROP TABLE IF EXISTS '.$this->db->protect_identifiers($table).';'.$newline.$newline;
 			}
@@ -92,7 +112,7 @@ class CI_DB_mysql_utility extends CI_DB_utility {
 			}
 
 			// If inserts are not needed we're done...
-			if ($add_insert == FALSE)
+			if ($add_insert === FALSE)
 			{
 				continue;
 			}
@@ -100,7 +120,7 @@ class CI_DB_mysql_utility extends CI_DB_utility {
 			// Grab all the data from the current table
 			$query = $this->db->query('SELECT * FROM '.$this->db->protect_identifiers($table));
 
-			if ($query->num_rows() == 0)
+			if ($query->num_rows() === 0)
 			{
 				continue;
 			}
@@ -120,7 +140,7 @@ class CI_DB_mysql_utility extends CI_DB_utility {
 							TRUE);
 
 				// Create a string of field names
-				$field_str .= $this->db->protect_identifiers($field->name).', ';
+				$field_str .= $this->db->escape_identifiers($field->name).', ';
 				$i++;
 			}
 
@@ -143,7 +163,7 @@ class CI_DB_mysql_utility extends CI_DB_utility {
 					else
 					{
 						// Escape the data if it's not an integer
-						$val_str .= ($is_int[$i] == FALSE) ? $this->db->escape($v) : $v;
+						$val_str .= ($is_int[$i] === FALSE) ? $this->db->escape($v) : $v;
 					}
 
 					// Append a comma