Update to MediaWiki 1.21.1

21 files changed, 1151 insertions, 2336 deletions

diff --git a/includes/db/CloneDatabase.php b/includes/db/CloneDatabase.php
index 4e43642f..4e443741 100644
--- a/includes/db/CloneDatabase.php
+++ b/includes/db/CloneDatabase.php
@@ -60,9 +60,9 @@ class CloneDatabase {
 	 * Constructor
 	 *
 	 * @param $db DatabaseBase A database subclass
-	 * @param $tablesToClone Array An array of tables to clone, unprefixed
-	 * @param $newTablePrefix String Prefix to assign to the tables
-	 * @param $oldTablePrefix String Prefix on current tables, if not $wgDBprefix
+	 * @param array $tablesToClone An array of tables to clone, unprefixed
+	 * @param string $newTablePrefix Prefix to assign to the tables
+	 * @param string $oldTablePrefix Prefix on current tables, if not $wgDBprefix
 	 * @param $dropCurrentTables bool
 	 */
 	public function __construct( DatabaseBase $db, array $tablesToClone,
@@ -77,7 +77,7 @@ class CloneDatabase {
 
 	/**
 	 * Set whether to use temporary tables or not
-	 * @param $u Bool Use temporary tables when cloning the structure
+	 * @param bool $u Use temporary tables when cloning the structure
 	 */
 	public function useTemporaryTables( $u = true ) {
 		$this->useTemporaryTables = $u;
@@ -87,35 +87,32 @@ class CloneDatabase {
 	 * Clone the table structure
 	 */
 	public function cloneTableStructure() {
-		
 		foreach( $this->tablesToClone as $tbl ) {
 			# Clean up from previous aborted run.  So that table escaping
 			# works correctly across DB engines, we need to change the pre-
 			# fix back and forth so tableName() works right.
-			
+
 			self::changePrefix( $this->oldTablePrefix );
 			$oldTableName = $this->db->tableName( $tbl, 'raw' );
-			
+
 			self::changePrefix( $this->newTablePrefix );
 			$newTableName = $this->db->tableName( $tbl, 'raw' );
-			
+
 			if( $this->dropCurrentTables && !in_array( $this->db->getType(), array( 'postgres', 'oracle' ) ) ) {
 				$this->db->dropTable( $tbl, __METHOD__ );
-				wfDebug( __METHOD__." dropping {$newTableName}\n", true);
+				wfDebug( __METHOD__ . " dropping {$newTableName}\n", true );
 				//Dropping the oldTable because the prefix was changed
 			}
 
 			# Create new table
-			wfDebug( __METHOD__." duplicating $oldTableName to $newTableName\n", true );
+			wfDebug( __METHOD__ . " duplicating $oldTableName to $newTableName\n", true );
 			$this->db->duplicateTableStructure( $oldTableName, $newTableName, $this->useTemporaryTables );
-			
 		}
-		
 	}
 
 	/**
 	 * Change the prefix back to the original.
-	 * @param $dropTables bool Optionally drop the tables we created
+	 * @param bool $dropTables Optionally drop the tables we created
 	 */
 	public function destroy( $dropTables = false ) {
 		if( $dropTables ) {
diff --git a/includes/db/Database.php b/includes/db/Database.php
index 5f10b97d..65a74abf 100644
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -49,10 +49,10 @@ interface DatabaseType {
 	/**
 	 * Open a connection to the database. Usually aborts on failure
 	 *
-	 * @param $server String: database server host
-	 * @param $user String: database user name
-	 * @param $password String: database user password
-	 * @param $dbName String: database name
+	 * @param string $server database server host
+	 * @param string $user database user name
+	 * @param string $password database user password
+	 * @param string $dbName database name
 	 * @return bool
 	 * @throws DBConnectionError
 	 */
@@ -62,9 +62,10 @@ interface DatabaseType {
 	 * Fetch the next row from the given result object, in object form.
 	 * Fields can be retrieved with $row->fieldname, with fields acting like
 	 * member variables.
+	 * If no more rows are available, false is returned.
 	 *
 	 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
-	 * @return Row object
+	 * @return object|bool
 	 * @throws DBUnexpectedError Thrown if the database returns an error
 	 */
 	function fetchObject( $res );
@@ -72,9 +73,10 @@ interface DatabaseType {
 	/**
 	 * Fetch the next row from the given result object, in associative array
 	 * form.  Fields are retrieved with $row['fieldname'].
+	 * If no more rows are available, false is returned.
 	 *
 	 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
-	 * @return Row object
+	 * @return array|bool
 	 * @throws DBUnexpectedError Thrown if the database returns an error
 	 */
 	function fetchRow( $res );
@@ -112,8 +114,8 @@ interface DatabaseType {
 	 * The value inserted should be fetched from nextSequenceValue()
 	 *
 	 * Example:
-	 * $id = $dbw->nextSequenceValue('page_page_id_seq');
-	 * $dbw->insert('page',array('page_id' => $id));
+	 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
+	 * $dbw->insert( 'page', array( 'page_id' => $id ) );
 	 * $id = $dbw->insertId();
 	 *
 	 * @return int
@@ -149,8 +151,8 @@ interface DatabaseType {
 	 * mysql_fetch_field() wrapper
 	 * Returns false if the field doesn't exist
 	 *
-	 * @param $table string: table name
-	 * @param $field string: field name
+	 * @param string $table table name
+	 * @param string $field field name
 	 *
 	 * @return Field
 	 */
@@ -158,9 +160,9 @@ interface DatabaseType {
 
 	/**
 	 * Get information about an index into an object
-	 * @param $table string: Table name
-	 * @param $index string: Index name
-	 * @param $fname string: Calling function name
+	 * @param string $table Table name
+	 * @param string $index Index name
+	 * @param string $fname Calling function name
 	 * @return Mixed: Database-specific index description class or false if the index does not exist
 	 */
 	function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
@@ -176,7 +178,7 @@ interface DatabaseType {
 	/**
 	 * Wrapper for addslashes()
 	 *
-	 * @param $s string: to be slashed.
+	 * @param string $s to be slashed.
 	 * @return string: slashed string.
 	 */
 	function strencode( $s );
@@ -249,6 +251,37 @@ abstract class DatabaseBase implements DatabaseType {
 
 	protected $delimiter = ';';
 
+	/**
+	 * Remembers the function name given for starting the most recent transaction via begin().
+	 * Used to provide additional context for error reporting.
+	 *
+	 * @var String
+	 * @see DatabaseBase::mTrxLevel
+	 */
+	private $mTrxFname = null;
+
+	/**
+	 * Record if possible write queries were done in the last transaction started
+	 *
+	 * @var Bool
+	 * @see DatabaseBase::mTrxLevel
+	 */
+	private $mTrxDoneWrites = false;
+
+	/**
+	 * Record if the current transaction was started implicitly due to DBO_TRX being set.
+	 *
+	 * @var Bool
+	 * @see DatabaseBase::mTrxLevel
+	 */
+	private $mTrxAutomatic = false;
+
+	/**
+	 * @since 1.21
+	 * @var file handle for upgrade
+	 */
+	protected $fileHandle = null;
+
 # ------------------------------------------------------------------------------
 # Accessors
 # ------------------------------------------------------------------------------
@@ -266,6 +299,13 @@ abstract class DatabaseBase implements DatabaseType {
 	}
 
 	/**
+	 * @return string: command delimiter used by this database engine
+	 */
+	public function getDelimiter() {
+		return $this->delimiter;
+	}
+
+	/**
 	 * Boolean, controls output of large amounts of debug information.
 	 * @param $debug bool|null
 	 *   - true to enable debugging
@@ -329,7 +369,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Historically, transactions were allowed to be "nested". This is no
 	 * longer supported, so this function really only returns a boolean.
 	 *
-	 * @param $level int An integer (0 or 1), or omitted to leave it unchanged.
+	 * @param int $level An integer (0 or 1), or omitted to leave it unchanged.
 	 * @return int The previous value
 	 */
 	public function trxLevel( $level = null ) {
@@ -338,7 +378,7 @@ abstract class DatabaseBase implements DatabaseType {
 
 	/**
 	 * Get/set the number of errors logged. Only useful when errors are ignored
-	 * @param $count int The count to set, or omitted to leave it unchanged.
+	 * @param int $count The count to set, or omitted to leave it unchanged.
 	 * @return int The error count
 	 */
 	public function errorCount( $count = null ) {
@@ -347,7 +387,7 @@ abstract class DatabaseBase implements DatabaseType {
 
 	/**
 	 * Get/set the table prefix.
-	 * @param $prefix string The table prefix to set, or omitted to leave it unchanged.
+	 * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
 	 * @return string The previous table prefix.
 	 */
 	public function tablePrefix( $prefix = null ) {
@@ -355,10 +395,19 @@ abstract class DatabaseBase implements DatabaseType {
 	}
 
 	/**
+	 * Set the filehandle to copy write statements to.
+	 *
+	 * @param $fh filehandle
+	 */
+	public function setFileHandle( $fh ) {
+		$this->fileHandle = $fh;
+	}
+
+	/**
 	 * Get properties passed down from the server info array of the load
 	 * balancer.
 	 *
-	 * @param $name string The entry of the info array to get, or null to get the
+	 * @param string $name The entry of the info array to get, or null to get the
 	 *   whole array
 	 *
 	 * @return LoadBalancer|null
@@ -441,7 +490,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Returns true if this database uses timestamps rather than integers
 	 *
 	 * @return bool
-	*/
+	 */
 	public function realTimestamps() {
 		return false;
 	}
@@ -509,7 +558,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @return bool
 	 */
 	public function writesOrCallbacksPending() {
-		return $this->mTrxLevel && ( $this->mDoneWrites || $this->mTrxIdleCallbacks );
+		return $this->mTrxLevel && ( $this->mTrxDoneWrites || $this->mTrxIdleCallbacks );
 	}
 
 	/**
@@ -536,7 +585,7 @@ abstract class DatabaseBase implements DatabaseType {
 		global $wgDebugDBTransactions;
 		$this->mFlags |= $flag;
 		if ( ( $flag & DBO_TRX) & $wgDebugDBTransactions ) {
-			wfDebug("Implicit transactions are now  disabled.\n");
+			wfDebug( "Implicit transactions are now  disabled.\n" );
 		}
 	}
 
@@ -549,7 +598,7 @@ abstract class DatabaseBase implements DatabaseType {
 		global $wgDebugDBTransactions;
 		$this->mFlags &= ~$flag;
 		if ( ( $flag & DBO_TRX ) && $wgDebugDBTransactions ) {
-			wfDebug("Implicit transactions are now disabled.\n");
+			wfDebug( "Implicit transactions are now disabled.\n" );
 		}
 	}
 
@@ -605,12 +654,12 @@ abstract class DatabaseBase implements DatabaseType {
 
 	/**
 	 * Constructor.
-	 * @param $server String: database server host
-	 * @param $user String: database user name
-	 * @param $password String: database user password
-	 * @param $dbName String: database name
+	 * @param string $server database server host
+	 * @param string $user database user name
+	 * @param string $password database user password
+	 * @param string $dbName database name
 	 * @param $flags
-	 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
+	 * @param string $tablePrefix database table prefixes. By default use the prefix gave in LocalSettings.php
 	 */
 	function __construct( $server = false, $user = false, $password = false, $dbName = false,
 		$flags = 0, $tablePrefix = 'get from global'
@@ -623,12 +672,12 @@ abstract class DatabaseBase implements DatabaseType {
 			if ( $wgCommandLineMode ) {
 				$this->mFlags &= ~DBO_TRX;
 				if ( $wgDebugDBTransactions ) {
-					wfDebug("Implicit transaction open disabled.\n");
+					wfDebug( "Implicit transaction open disabled.\n" );
 				}
 			} else {
 				$this->mFlags |= DBO_TRX;
 				if ( $wgDebugDBTransactions ) {
-					wfDebug("Implicit transaction open enabled.\n");
+					wfDebug( "Implicit transaction open enabled.\n" );
 				}
 			}
 		}
@@ -671,14 +720,14 @@ abstract class DatabaseBase implements DatabaseType {
 	 *
 	 * @since 1.18
 	 *
-	 * @param $dbType String A possible DB type
-	 * @param $p Array An array of options to pass to the constructor.
+	 * @param string $dbType A possible DB type
+	 * @param array $p An array of options to pass to the constructor.
 	 *    Valid options are: host, user, password, dbname, flags, tablePrefix
 	 * @return DatabaseBase subclass or null
 	 */
-	public final static function factory( $dbType, $p = array() ) {
+	final public static function factory( $dbType, $p = array() ) {
 		$canonicalDBTypes = array(
-			'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
+			'mysql', 'postgres', 'sqlite', 'oracle', 'mssql'
 		);
 		$dbType = strtolower( $dbType );
 		$class = 'Database' . ucfirst( $dbType );
@@ -724,7 +773,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @param $errno
 	 * @param $errstr
 	 */
-	protected function connectionErrorHandler( $errno,  $errstr ) {
+	protected function connectionErrorHandler( $errno, $errstr ) {
 		$this->mPHPError = $errstr;
 	}
 
@@ -732,6 +781,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Closes a database connection.
 	 * if it is open : commits any open transactions
 	 *
+	 * @throws MWException
 	 * @return Bool operation success. true if already closed.
 	 */
 	public function close() {
@@ -741,8 +791,14 @@ abstract class DatabaseBase implements DatabaseType {
 		$this->mOpened = false;
 		if ( $this->mConn ) {
 			if ( $this->trxLevel() ) {
-				$this->commit( __METHOD__ );
+				if ( !$this->mTrxAutomatic ) {
+					wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
+						" performing implicit commit before closing connection!" );
+				}
+
+				$this->commit( __METHOD__, 'flush' );
 			}
+
 			$ret = $this->closeConnection();
 			$this->mConn = false;
 			return $ret;
@@ -756,10 +812,11 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @since 1.20
 	 * @return bool: Whether connection was closed successfully
 	 */
-	protected abstract function closeConnection();
+	abstract protected function closeConnection();
 
 	/**
-	 * @param $error String: fallback error message, used if none is given by DB
+	 * @param string $error fallback error message, used if none is given by DB
+	 * @throws DBConnectionError
 	 */
 	function reportConnectionError( $error = 'Unknown error' ) {
 		$myError = $this->lastError();
@@ -777,7 +834,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @param  $sql String: SQL query.
 	 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
 	 */
-	protected abstract function doQuery( $sql );
+	abstract protected function doQuery( $sql );
 
 	/**
 	 * Determine whether a query writes to the DB.
@@ -809,9 +866,9 @@ abstract class DatabaseBase implements DatabaseType {
 	 *     comment (you can use __METHOD__ or add some extra info)
 	 * @param  $tempIgnore Boolean:   Whether to avoid throwing an exception on errors...
 	 *     maybe best to catch the exception instead?
+	 * @throws MWException
 	 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
 	 *     for a successful read query, or false on failure if $tempIgnore set
-	 * @throws DBQueryError Thrown when the database returns an error of any kind
 	 */
 	public function query( $sql, $fname = '', $tempIgnore = false ) {
 		$isMaster = !is_null( $this->getLBInfo( 'master' ) );
@@ -849,24 +906,34 @@ abstract class DatabaseBase implements DatabaseType {
 		} else {
 			$userName = '';
 		}
-		$commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
+
+		// Add trace comment to the begin of the sql string, right after the operator.
+		// Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
+		$commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
 
 		# If DBO_TRX is set, start a transaction
-		if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
-			$sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
-			# avoid establishing transactions for SHOW and SET statements too -
+		if ( ( $this->mFlags & DBO_TRX ) && !$this->mTrxLevel &&
+			$sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
+		{
+			# Avoid establishing transactions for SHOW and SET statements too -
 			# that would delay transaction initializations to once connection
 			# is really used by application
 			$sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
 			if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
 				global $wgDebugDBTransactions;
 				if ( $wgDebugDBTransactions ) {
-					wfDebug("Implicit transaction start.\n");
+					wfDebug( "Implicit transaction start.\n" );
 				}
 				$this->begin( __METHOD__ . " ($fname)" );
+				$this->mTrxAutomatic = true;
 			}
 		}
 
+		# Keep track of whether the transaction has write queries pending
+		if ( $this->mTrxLevel && !$this->mTrxDoneWrites && $this->isWriteQuery( $sql ) ) {
+			$this->mTrxDoneWrites = true;
+		}
+
 		if ( $this->debug() ) {
 			static $cnt = 0;
 
@@ -933,6 +1000,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @param $sql String
 	 * @param $fname String
 	 * @param $tempIgnore Boolean
+	 * @throws DBQueryError
 	 */
 	public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 		# Ignore errors during error handling to avoid infinite recursion
@@ -981,7 +1049,7 @@ abstract class DatabaseBase implements DatabaseType {
 
 	/**
 	 * Execute a prepared query with the various arguments
-	 * @param $prepared String: the prepared sql
+	 * @param string $prepared the prepared sql
 	 * @param $args Mixed: Either an array here, or put scalars as varargs
 	 *
 	 * @return ResultWrapper
@@ -1001,8 +1069,8 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * For faking prepared SQL statements on DBs that don't support it directly.
 	 *
-	 * @param $preparedQuery String: a 'preparable' SQL statement
-	 * @param $args Array of arguments to fill it with
+	 * @param string $preparedQuery a 'preparable' SQL statement
+	 * @param array $args of arguments to fill it with
 	 * @return string executable SQL
 	 */
 	public function fillPrepared( $preparedQuery, $args ) {
@@ -1019,6 +1087,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * while we're doing this.
 	 *
 	 * @param $matches Array
+	 * @throws DBUnexpectedError
 	 * @return String
 	 */
 	protected function fillPreparedArg( $matches ) {
@@ -1028,7 +1097,7 @@ abstract class DatabaseBase implements DatabaseType {
 			case '\\&': return '&';
 		}
 
-		list( /* $n */ , $arg ) = each( $this->preparedArgs );
+		list( /* $n */, $arg ) = each( $this->preparedArgs );
 
 		switch( $matches[1] ) {
 			case '?': return $this->addQuotes( $arg );
@@ -1058,12 +1127,12 @@ abstract class DatabaseBase implements DatabaseType {
 	 *
 	 * If no result rows are returned from the query, false is returned.
 	 *
-	 * @param $table string|array Table name. See DatabaseBase::select() for details.
-	 * @param $var string The field name to select. This must be a valid SQL
+	 * @param string|array $table Table name. See DatabaseBase::select() for details.
+	 * @param string $var The field name to select. This must be a valid SQL
 	 *   fragment: do not use unvalidated user input.
-	 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
-	 * @param $fname string The function name of the caller.
-	 * @param $options string|array The query options. See DatabaseBase::select() for details.
+	 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
+	 * @param string $fname The function name of the caller.
+	 * @param string|array $options The query options. See DatabaseBase::select() for details.
 	 *
 	 * @return bool|mixed The value from the field, or false on failure.
 	 */
@@ -1095,7 +1164,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Returns an optional USE INDEX clause to go after the table, and a
 	 * string to go at the end of the query.
 	 *
-	 * @param $options Array: associative array of options to be turned into
+	 * @param array $options associative array of options to be turned into
 	 *              an SQL query, valid keys are listed in the function.
 	 * @return Array
 	 * @see DatabaseBase::select()
@@ -1112,26 +1181,9 @@ abstract class DatabaseBase implements DatabaseType {
 			}
 		}
 
-		if ( isset( $options['GROUP BY'] ) ) {
-			$gb = is_array( $options['GROUP BY'] )
-				? implode( ',', $options['GROUP BY'] )
-				: $options['GROUP BY'];
-			$preLimitTail .= " GROUP BY {$gb}";
-		}
+		$preLimitTail .= $this->makeGroupByWithHaving( $options );
 
-		if ( isset( $options['HAVING'] ) ) {
-			$having = is_array( $options['HAVING'] )
-				? $this->makeList( $options['HAVING'], LIST_AND )
-				: $options['HAVING'];
-			$preLimitTail .= " HAVING {$having}";
-		}
-
-		if ( isset( $options['ORDER BY'] ) ) {
-			$ob = is_array( $options['ORDER BY'] )
-				? implode( ',', $options['ORDER BY'] )
-				: $options['ORDER BY'];
-			$preLimitTail .= " ORDER BY {$ob}";
-		}
+		$preLimitTail .= $this->makeOrderBy( $options );
 
 		// if (isset($options['LIMIT'])) {
 		//	$tailOpts .= $this->limitResult('', $options['LIMIT'],
@@ -1194,14 +1246,57 @@ abstract class DatabaseBase implements DatabaseType {
 	}
 
 	/**
+	 * Returns an optional GROUP BY with an optional HAVING
+	 *
+	 * @param array $options associative array of options
+	 * @return string
+	 * @see DatabaseBase::select()
+	 * @since 1.21
+	 */
+	public function makeGroupByWithHaving( $options ) {
+		$sql = '';
+		if ( isset( $options['GROUP BY'] ) ) {
+			$gb = is_array( $options['GROUP BY'] )
+				? implode( ',', $options['GROUP BY'] )
+				: $options['GROUP BY'];
+			$sql .= ' GROUP BY ' . $gb;
+		}
+		if ( isset( $options['HAVING'] ) ) {
+			$having = is_array( $options['HAVING'] )
+				? $this->makeList( $options['HAVING'], LIST_AND )
+				: $options['HAVING'];
+			$sql .= ' HAVING ' . $having;
+		}
+		return $sql;
+	}
+
+	/**
+	 * Returns an optional ORDER BY
+	 *
+	 * @param array $options associative array of options
+	 * @return string
+	 * @see DatabaseBase::select()
+	 * @since 1.21
+	 */
+	public function makeOrderBy( $options ) {
+		if ( isset( $options['ORDER BY'] ) ) {
+			$ob = is_array( $options['ORDER BY'] )
+				? implode( ',', $options['ORDER BY'] )
+				: $options['ORDER BY'];
+			return ' ORDER BY ' . $ob;
+		}
+		return '';
+	}
+
+	/**
 	 * Execute a SELECT query constructed using the various parameters provided.
 	 * See below for full details of the parameters.
 	 *
-	 * @param $table String|Array Table name
-	 * @param $vars String|Array Field names
-	 * @param $conds String|Array Conditions
-	 * @param $fname String Caller function name
-	 * @param $options Array Query options
+	 * @param string|array $table Table name
+	 * @param string|array $vars Field names
+	 * @param string|array $conds Conditions
+	 * @param string $fname Caller function name
+	 * @param array $options Query options
 	 * @param $join_conds Array Join conditions
 	 *
 	 * @param $table string|array
@@ -1325,7 +1420,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * join, the second is an SQL fragment giving the join condition for that
 	 * table. For example:
 	 *
-	 *    array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
+	 *    array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
 	 *
 	 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
 	 *   with no rows in it will be returned. If there was a query error, a
@@ -1345,11 +1440,11 @@ abstract class DatabaseBase implements DatabaseType {
 	 * doing UNION queries, where the SQL text of each query is needed. In general,
 	 * however, callers outside of Database classes should just use select().
 	 *
-	 * @param $table string|array Table name
-	 * @param $vars string|array Field names
-	 * @param $conds string|array Conditions
-	 * @param $fname string Caller function name
-	 * @param $options string|array Query options
+	 * @param string|array $table Table name
+	 * @param string|array $vars Field names
+	 * @param string|array $conds Conditions
+	 * @param string $fname Caller function name
+	 * @param string|array $options Query options
 	 * @param $join_conds string|array Join conditions
 	 *
 	 * @return string SQL query string.
@@ -1413,11 +1508,11 @@ abstract class DatabaseBase implements DatabaseType {
 	 * that a single row object is returned. If the query returns no rows,
 	 * false is returned.
 	 *
-	 * @param $table string|array Table name
-	 * @param $vars string|array Field names
-	 * @param $conds array Conditions
-	 * @param $fname string Caller function name
-	 * @param $options string|array Query options
+	 * @param string|array $table Table name
+	 * @param string|array $vars Field names
+	 * @param array $conds Conditions
+	 * @param string $fname Caller function name
+	 * @param string|array $options Query options
 	 * @param $join_conds array|string Join conditions
 	 *
 	 * @return object|bool
@@ -1455,11 +1550,11 @@ abstract class DatabaseBase implements DatabaseType {
 	 *
 	 * Takes the same arguments as DatabaseBase::select().
 	 *
-	 * @param $table String: table name
-	 * @param Array|string $vars : unused
-	 * @param Array|string $conds : filters on the table
-	 * @param $fname String: function name for profiling
-	 * @param $options Array: options for select
+	 * @param string $table table name
+	 * @param array|string $vars : unused
+	 * @param array|string $conds : filters on the table
+	 * @param string $fname function name for profiling
+	 * @param array $options options for select
 	 * @return Integer: row count
 	 */
 	public function estimateRowCount( $table, $vars = '*', $conds = '',
@@ -1480,7 +1575,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Removes most variables from an SQL query and replaces them with X or N for numbers.
 	 * It's only slightly flawed. Don't use for anything important.
 	 *
-	 * @param $sql String A SQL Query
+	 * @param string $sql A SQL Query
 	 *
 	 * @return string
 	 */
@@ -1507,9 +1602,9 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Determines whether a field exists in a table
 	 *
-	 * @param $table String: table name
-	 * @param $field String: filed to check on that table
-	 * @param $fname String: calling function name (optional)
+	 * @param string $table table name
+	 * @param string $field filed to check on that table
+	 * @param string $fname calling function name (optional)
 	 * @return Boolean: whether $table has filed $field
 	 */
 	public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
@@ -1530,6 +1625,10 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @return bool|null
 	 */
 	public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
+		if( !$this->tableExists( $table ) ) {
+			return null;
+		}
+
 		$info = $this->indexInfo( $table, $index, $fname );
 		if ( is_null( $info ) ) {
 			return null;
@@ -1626,7 +1725,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 *                 DatabaseBase::tableName().
 	 * @param $a       Array of rows to insert
 	 * @param $fname   String Calling function name (use __METHOD__) for logs/profiling
-	 * @param $options Array of options
+	 * @param array $options of options
 	 *
 	 * @return bool
 	 */
@@ -1642,6 +1741,10 @@ abstract class DatabaseBase implements DatabaseType {
 			$options = array( $options );
 		}
 
+		$fh = null;
+		if ( isset( $options['fileHandle'] ) ) {
+			$fh = $options['fileHandle'];
+		}
 		$options = $this->makeInsertOptions( $options );
 
 		if ( isset( $a[0] ) && is_array( $a[0] ) ) {
@@ -1669,13 +1772,19 @@ abstract class DatabaseBase implements DatabaseType {
 			$sql .= '(' . $this->makeList( $a ) . ')';
 		}
 
+		if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
+			return false;
+		} elseif ( $fh !== null ) {
+			return true;
+		}
+
 		return (bool)$this->query( $sql, $fname );
 	}
 
 	/**
 	 * Make UPDATE options for the DatabaseBase::update function
 	 *
-	 * @param $options Array: The options passed to DatabaseBase::update
+	 * @param array $options The options passed to DatabaseBase::update
 	 * @return string
 	 */
 	protected function makeUpdateOptions( $options ) {
@@ -1702,7 +1811,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @param $table  String name of the table to UPDATE. This will be passed through
 	 *                DatabaseBase::tableName().
 	 *
-	 * @param $values Array:  An array of values to SET. For each array element,
+	 * @param array $values  An array of values to SET. For each array element,
 	 *                the key gives the field name, and the value gives the data
 	 *                to set that field to. The data will be quoted by
 	 *                DatabaseBase::addQuotes().
@@ -1714,7 +1823,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * @param $fname  String: The function name of the caller (from __METHOD__),
 	 *                for logging and profiling.
 	 *
-	 * @param $options Array: An array of UPDATE options, can be:
+	 * @param array $options An array of UPDATE options, can be:
 	 *                   - IGNORE: Ignore unique key conflicts
 	 *                   - LOW_PRIORITY: MySQL-specific, see MySQL manual.
 	 * @return Boolean
@@ -1733,8 +1842,8 @@ abstract class DatabaseBase implements DatabaseType {
 
 	/**
 	 * Makes an encoded list of strings from an array
-	 * @param $a Array containing the data
-	 * @param $mode int Constant
+	 * @param array $a containing the data
+	 * @param int $mode Constant
 	 *      - LIST_COMMA:          comma separated, no field names
 	 *      - LIST_AND:            ANDed WHERE clause (without the WHERE). See
 	 *        the documentation for $conds in DatabaseBase::select().
@@ -1742,6 +1851,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 *      - LIST_SET:            comma separated with field names, like a SET clause
 	 *      - LIST_NAMES:          comma separated field names
 	 *
+	 * @throws MWException|DBUnexpectedError
 	 * @return string
 	 */
 	public function makeList( $a, $mode = LIST_COMMA ) {
@@ -1771,7 +1881,7 @@ abstract class DatabaseBase implements DatabaseType {
 				$list .= "$value";
 			} elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
 				if ( count( $value ) == 0 ) {
-					throw new MWException( __METHOD__ . ': empty input' );
+					throw new MWException( __METHOD__ . ": empty input for field $field" );
 				} elseif ( count( $value ) == 1 ) {
 					// Special-case single values, as IN isn't terribly efficient
 					// Don't necessarily assume the single key is 0; we don't
@@ -1803,10 +1913,10 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Build a partial where clause from a 2-d array such as used for LinkBatch.
 	 * The keys on each level may be either integers or strings.
 	 *
-	 * @param $data Array: organized as 2-d
+	 * @param array $data organized as 2-d
 	 *              array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
-	 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
-	 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
+	 * @param string $baseKey field name to match the base-level keys to (eg 'pl_namespace')
+	 * @param string $subKey field name to match the sub-level keys to (eg 'pl_title')
 	 * @return Mixed: string SQL fragment, or false if no items in array.
 	 */
 	public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
@@ -1868,7 +1978,7 @@ abstract class DatabaseBase implements DatabaseType {
 
 	/**
 	 * Build a concatenation list to feed into a SQL query
-	 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
+	 * @param array $stringList list of raw SQL expressions; caller is responsible for any quoting
 	 * @return String
 	 */
 	public function buildConcat( $stringList ) {
@@ -1916,8 +2026,8 @@ abstract class DatabaseBase implements DatabaseType {
 	 * themselves. Pass the canonical name to such functions. This is only needed
 	 * when calling query() directly.
 	 *
-	 * @param $name String: database table name
-	 * @param $format String One of:
+	 * @param string $name database table name
+	 * @param string $format One of:
 	 *   quoted - Automatically pass the table name through addIdentifierQuotes()
 	 *            so that it can be used in a query.
 	 *   raw - Do not add identifier quotes to the table name
@@ -1947,47 +2057,39 @@ abstract class DatabaseBase implements DatabaseType {
 		# Split database and table into proper variables.
 		# We reverse the explode so that database.table and table both output
 		# the correct table.
-		$dbDetails = array_reverse( explode( '.', $name, 2 ) );
-		if ( isset( $dbDetails[1] ) ) {
-			list( $table, $database ) = $dbDetails;
+		$dbDetails = explode( '.', $name, 2 );
+		if ( count( $dbDetails ) == 2 ) {
+			list( $database, $table ) = $dbDetails;
+			# We don't want any prefix added in this case
+			$prefix = '';
 		} else {
 			list( $table ) = $dbDetails;
-		}
-		$prefix = $this->mTablePrefix; # Default prefix
-
-		# A database name has been specified in input. We don't want any
-		# prefixes added.
-		if ( isset( $database ) ) {
-			$prefix = '';
+			if ( $wgSharedDB !== null # We have a shared database
+				&& !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
+				&& in_array( $table, $wgSharedTables ) # A shared table is selected
+			) {
+				$database = $wgSharedDB;
+				$prefix = $wgSharedPrefix === null ? $this->mTablePrefix : $wgSharedPrefix;
+			} else {
+				$database = null;
+				$prefix = $this->mTablePrefix; # Default prefix
+			}
 		}
 
-		# Note that we use the long format because php will complain in in_array if
-		# the input is not an array, and will complain in is_array if it is not set.
-		if ( !isset( $database ) # Don't use shared database if pre selected.
-		 && isset( $wgSharedDB ) # We have a shared database
-		 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
-		 && isset( $wgSharedTables )
-		 && is_array( $wgSharedTables )
-		 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
-			$database = $wgSharedDB;
-			$prefix   = isset( $wgSharedPrefix ) ? $wgSharedPrefix : $prefix;
+		# Quote $table and apply the prefix if not quoted.
+		$tableName = "{$prefix}{$table}";
+		if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) ) {
+			$tableName = $this->addIdentifierQuotes( $tableName );
 		}
 
-		# Quote the $database and $table and apply the prefix if not quoted.
-		if ( isset( $database ) ) {
+		# Quote $database and merge it with the table name if needed
+		if ( $database !== null ) {
 			if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
 				$database = $this->addIdentifierQuotes( $database );
 			}
+			$tableName = $database . '.' . $tableName;
 		}
 
-		$table = "{$prefix}{$table}";
-		if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
-			$table = $this->addIdentifierQuotes( "{$table}" );
-		}
-
-		# Merge our database and table into our final table name.
-		$tableName = ( isset( $database ) ? "{$database}.{$table}" : "{$table}" );
-
 		return $tableName;
 	}
 
@@ -1996,7 +2098,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * This is handy when you need to construct SQL for joins
 	 *
 	 * Example:
-	 * extract($dbr->tableNames('user','watchlist'));
+	 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
 	 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
 	 *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
 	 *
@@ -2018,7 +2120,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * This is handy when you need to construct SQL for joins
 	 *
 	 * Example:
-	 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
+	 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
 	 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
 	 *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
 	 *
@@ -2039,8 +2141,8 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Get an aliased table name
 	 * e.g. tableName AS newTableName
 	 *
-	 * @param $name string Table name, see tableName()
-	 * @param $alias string|bool Alias (optional)
+	 * @param string $name Table name, see tableName()
+	 * @param string|bool $alias Alias (optional)
 	 * @return string SQL name for aliased table. Will not alias a table to its own name
 	 */
 	public function tableNameWithAlias( $name, $alias = false ) {
@@ -2072,8 +2174,8 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Get an aliased field name
 	 * e.g. fieldName AS newFieldName
 	 *
-	 * @param $name string Field name
-	 * @param $alias string|bool Alias (optional)
+	 * @param string $name Field name
+	 * @param string|bool $alias Alias (optional)
 	 * @return string SQL name for aliased field. Will not alias a field to its own name
 	 */
 	public function fieldNameWithAlias( $name, $alias = false ) {
@@ -2105,7 +2207,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Get the aliased table name clause for a FROM clause
 	 * which might have a JOIN and/or USE INDEX clause
 	 *
-	 * @param $tables array ( [alias] => table )
+	 * @param array $tables ( [alias] => table )
 	 * @param $use_index array Same as for select()
 	 * @param $join_conds array Same as for select()
 	 * @return string
@@ -2336,12 +2438,12 @@ abstract class DatabaseBase implements DatabaseType {
 	 * to collide. However if you do this, you run the risk of encountering
 	 * errors which wouldn't have occurred in MySQL.
 	 *
-	 * @param $table String: The table to replace the row(s) in.
-	 * @param $rows array Can be either a single row to insert, or multiple rows,
+	 * @param string $table The table to replace the row(s) in.
+	 * @param array $rows Can be either a single row to insert, or multiple rows,
 	 *    in the same format as for DatabaseBase::insert()
-	 * @param $uniqueIndexes array is an array of indexes. Each element may be either
+	 * @param array $uniqueIndexes is an array of indexes. Each element may be either
 	 *    a field name or an array of field names
-	 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
+	 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 	 */
 	public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
 		$quotedTable = $this->tableName( $table );
@@ -2394,9 +2496,9 @@ abstract class DatabaseBase implements DatabaseType {
 	 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
 	 * statement.
 	 *
-	 * @param $table string Table name
-	 * @param $rows array Rows to insert
-	 * @param $fname string Caller function name
+	 * @param string $table Table name
+	 * @param array $rows Rows to insert
+	 * @param string $fname Caller function name
 	 *
 	 * @return ResultWrapper
 	 */
@@ -2443,6 +2545,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 *                    ANDed together in the WHERE clause
 	 * @param $fname      String: Calling function name (use __METHOD__) for
 	 *                    logs/profiling
+	 * @throws DBUnexpectedError
 	 */
 	public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
 		$fname = 'DatabaseBase::deleteJoin' )
@@ -2503,12 +2606,13 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * DELETE query wrapper.
 	 *
-	 * @param $table Array Table name
-	 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
+	 * @param array $table Table name
+	 * @param string|array $conds of conditions. See $conds in DatabaseBase::select() for
 	 *               the format. Use $conds == "*" to delete all rows
-	 * @param $fname String name of the calling function
+	 * @param string $fname name of the calling function
 	 *
-	 * @return bool
+	 * @throws DBUnexpectedError
+	 * @return bool|ResultWrapper
 	 */
 	public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
 		if ( !$conds ) {
@@ -2529,24 +2633,24 @@ abstract class DatabaseBase implements DatabaseType {
 	 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
 	 * into another table.
 	 *
-	 * @param $destTable string The table name to insert into
-	 * @param $srcTable string|array May be either a table name, or an array of table names
+	 * @param string $destTable The table name to insert into
+	 * @param string|array $srcTable May be either a table name, or an array of table names
 	 *    to include in a join.
 	 *
-	 * @param $varMap array must be an associative array of the form
+	 * @param array $varMap must be an associative array of the form
 	 *    array( 'dest1' => 'source1', ...). Source items may be literals
 	 *    rather than field names, but strings should be quoted with
 	 *    DatabaseBase::addQuotes()
 	 *
-	 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
+	 * @param array $conds Condition array. See $conds in DatabaseBase::select() for
 	 *    the details of the format of condition arrays. May be "*" to copy the
 	 *    whole table.
 	 *
-	 * @param $fname string The function name of the caller, from __METHOD__
+	 * @param string $fname The function name of the caller, from __METHOD__
 	 *
-	 * @param $insertOptions array Options for the INSERT part of the query, see
+	 * @param array $insertOptions Options for the INSERT part of the query, see
 	 *    DatabaseBase::insert() for details.
-	 * @param $selectOptions array Options for the SELECT part of the query, see
+	 * @param array $selectOptions Options for the SELECT part of the query, see
 	 *    DatabaseBase::select() for details.
 	 *
 	 * @return ResultWrapper
@@ -2568,7 +2672,7 @@ abstract class DatabaseBase implements DatabaseType {
 		list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 
 		if ( is_array( $srcTable ) ) {
-			$srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
+			$srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 		} else {
 			$srcTable = $this->tableName( $srcTable );
 		}
@@ -2602,10 +2706,11 @@ abstract class DatabaseBase implements DatabaseType {
 	 * The version provided by default works in MySQL and SQLite.  It will very
 	 * likely need to be overridden for most other DBMSes.
 	 *
-	 * @param $sql String SQL query we will append the limit too
+	 * @param string $sql SQL query we will append the limit too
 	 * @param $limit Integer the SQL limit
 	 * @param $offset Integer|bool the SQL offset (default false)
 	 *
+	 * @throws DBUnexpectedError
 	 * @return string
 	 */
 	public function limitResult( $sql, $limit, $offset = false ) {
@@ -2630,7 +2735,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Construct a UNION query
 	 * This is used for providing overload point for other DB abstractions
 	 * not compatible with the MySQL syntax.
-	 * @param $sqls Array: SQL statements to combine
+	 * @param array $sqls SQL statements to combine
 	 * @param $all Boolean: use UNION ALL
 	 * @return String: SQL fragment
 	 */
@@ -2643,9 +2748,9 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Returns an SQL expression for a simple conditional.  This doesn't need
 	 * to be overridden unless CASE isn't supported in your DBMS.
 	 *
-	 * @param $cond string|array SQL expression which will result in a boolean value
-	 * @param $trueVal String: SQL expression to return if true
-	 * @param $falseVal String: SQL expression to return if false
+	 * @param string|array $cond SQL expression which will result in a boolean value
+	 * @param string $trueVal SQL expression to return if true
+	 * @param string $falseVal SQL expression to return if false
 	 * @return String: SQL fragment
 	 */
 	public function conditional( $cond, $trueVal, $falseVal ) {
@@ -2659,9 +2764,9 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Returns a comand for str_replace function in SQL query.
 	 * Uses REPLACE() in MySQL
 	 *
-	 * @param $orig String: column to modify
-	 * @param $old String: column to seek
-	 * @param $new String: column to replace with
+	 * @param string $orig column to modify
+	 * @param string $old column to seek
+	 * @param string $new column to replace with
 	 *
 	 * @return string
 	 */
@@ -2854,8 +2959,9 @@ abstract class DatabaseBase implements DatabaseType {
 	 *
 	 * This is useful for updates to different systems or separate transactions are needed.
 	 *
+	 * @since 1.20
+	 *
 	 * @param Closure $callback
-	 * @return void
 	 */
 	final public function onTransactionIdle( Closure $callback ) {
 		if ( $this->mTrxLevel ) {
@@ -2866,7 +2972,9 @@ abstract class DatabaseBase implements DatabaseType {
 	}
 
 	/**
-	 * Actually run the "on transaction idle" callbacks
+	 * Actually run the "on transaction idle" callbacks.
+	 *
+	 * @since 1.20
 	 */
 	protected function runOnTransactionIdleCallbacks() {
 		$autoTrx = $this->getFlag( DBO_TRX ); // automatic begin() enabled?
@@ -2890,19 +2998,50 @@ abstract class DatabaseBase implements DatabaseType {
 	}
 
 	/**
-	 * Begin a transaction
+	 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
+	 * new transaction is started.
+	 *
+	 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
+	 * any previous database query will have started a transaction automatically.
+	 *
+	 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
+	 * transaction was started automatically because of the DBO_TRX flag.
 	 *
 	 * @param $fname string
 	 */
 	final public function begin( $fname = 'DatabaseBase::begin' ) {
+		global $wgDebugDBTransactions;
+
 		if ( $this->mTrxLevel ) { // implicit commit
+			if ( !$this->mTrxAutomatic ) {
+				// We want to warn about inadvertently nested begin/commit pairs, but not about
+				// auto-committing implicit transactions that were started by query() via DBO_TRX
+				$msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
+					" performing implicit commit!";
+				wfWarn( $msg );
+				wfLogDBError( $msg );
+			} else {
+				// if the transaction was automatic and has done write operations,
+				// log it if $wgDebugDBTransactions is enabled.
+				if ( $this->mTrxDoneWrites && $wgDebugDBTransactions ) {
+					wfDebug( "$fname: Automatic transaction with writes in progress" .
+						" (from {$this->mTrxFname}), performing implicit commit!\n" );
+				}
+			}
+
 			$this->doCommit( $fname );
 			$this->runOnTransactionIdleCallbacks();
 		}
+
 		$this->doBegin( $fname );
+		$this->mTrxFname = $fname;
+		$this->mTrxDoneWrites = false;
+		$this->mTrxAutomatic = false;
 	}
 
 	/**
+	 * Issues the BEGIN command to the database server.
+	 *
 	 * @see DatabaseBase::begin()
 	 * @param type $fname
 	 */
@@ -2912,16 +3051,39 @@ abstract class DatabaseBase implements DatabaseType {
 	}
 
 	/**
-	 * End a transaction
+	 * Commits a transaction previously started using begin().
+	 * If no transaction is in progress, a warning is issued.
+	 *
+	 * Nesting of transactions is not supported.
 	 *
 	 * @param $fname string
-	 */
-	final public function commit( $fname = 'DatabaseBase::commit' ) {
+	 * @param string $flush Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
+	 *        transactions, or calling commit when no transaction is in progress.
+	 *        This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
+	 *        that it is safe to ignore these warnings in your context.
+	 */
+	final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
+		if ( $flush != 'flush' ) {
+			if ( !$this->mTrxLevel ) {
+				wfWarn( "$fname: No transaction to commit, something got out of sync!" );
+			} elseif( $this->mTrxAutomatic ) {
+				wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
+			}
+		} else {
+			if ( !$this->mTrxLevel ) {
+				return; // nothing to do
+			} elseif( !$this->mTrxAutomatic ) {
+				wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
+			}
+		}
+
 		$this->doCommit( $fname );
 		$this->runOnTransactionIdleCallbacks();
 	}
 
 	/**
+	 * Issues the COMMIT command to the database server.
+	 *
 	 * @see DatabaseBase::commit()
 	 * @param type $fname
 	 */
@@ -2933,17 +3095,24 @@ abstract class DatabaseBase implements DatabaseType {
 	}
 
 	/**
-	 * Rollback a transaction.
+	 * Rollback a transaction previously started using begin().
+	 * If no transaction is in progress, a warning is issued.
+	 *
 	 * No-op on non-transactional databases.
 	 *
 	 * @param $fname string
 	 */
 	final public function rollback( $fname = 'DatabaseBase::rollback' ) {
+		if ( !$this->mTrxLevel ) {
+			wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
+		}
 		$this->doRollback( $fname );
 		$this->mTrxIdleCallbacks = array(); // cancel
 	}
 
 	/**
+	 * Issues the ROLLBACK command to the database server.
+	 *
 	 * @see DatabaseBase::rollback()
 	 * @param type $fname
 	 */
@@ -2962,10 +3131,11 @@ abstract class DatabaseBase implements DatabaseType {
 	 * The table names passed to this function shall not be quoted (this
 	 * function calls addIdentifierQuotes when needed).
 	 *
-	 * @param $oldName String: name of table whose structure should be copied
-	 * @param $newName String: name of table to be created
+	 * @param string $oldName name of table whose structure should be copied
+	 * @param string $newName name of table to be created
 	 * @param $temporary Boolean: whether the new table should be temporary
-	 * @param $fname String: calling function name
+	 * @param string $fname calling function name
+	 * @throws MWException
 	 * @return Boolean: true if operation was successful
 	 */
 	public function duplicateTableStructure( $oldName, $newName, $temporary = false,
@@ -2978,8 +3148,9 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * List all tables on the database
 	 *
-	 * @param $prefix string Only show tables with this prefix, e.g. mw_
-	 * @param $fname String: calling function name
+	 * @param string $prefix Only show tables with this prefix, e.g. mw_
+	 * @param string $fname calling function name
+	 * @throws MWException
 	 */
 	function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
 		throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
@@ -3122,15 +3293,18 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Returns true on success, error string or exception on failure (depending
 	 * on object's error ignore settings).
 	 *
-	 * @param $filename String: File name to open
-	 * @param $lineCallback Callback: Optional function called before reading each line
-	 * @param $resultCallback Callback: Optional function called for each MySQL result
-	 * @param $fname String: Calling function name or false if name should be
+	 * @param string $filename File name to open
+	 * @param bool|callable $lineCallback Optional function called before reading each line
+	 * @param bool|callable $resultCallback Optional function called for each MySQL result
+	 * @param bool|string $fname Calling function name or false if name should be
 	 *      generated dynamically using $filename
+	 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
+	 * @throws MWException
+	 * @throws Exception|MWException
 	 * @return bool|string
 	 */
 	public function sourceFile(
-		$filename, $lineCallback = false, $resultCallback = false, $fname = false
+		$filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
 	) {
 		wfSuppressWarnings();
 		$fp = fopen( $filename, 'r' );
@@ -3145,7 +3319,7 @@ abstract class DatabaseBase implements DatabaseType {
 		}
 
 		try {
-			$error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
+			$error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
 		}
 		catch ( MWException $e ) {
 			fclose( $fp );
@@ -3162,7 +3336,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * from updaters.inc. Keep in mind this always returns a patch, as
 	 * it fails back to MySQL if no DB-specific patch can be found
 	 *
-	 * @param $patch String The name of the patch, like patch-something.sql
+	 * @param string $patch The name of the patch, like patch-something.sql
 	 * @return String Full path to patch file
 	 */
 	public function patchPath( $patch ) {
@@ -3181,7 +3355,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
 	 * all. If it's set to false, $GLOBALS will be used.
 	 *
-	 * @param $vars bool|array mapping variable name to value.
+	 * @param bool|array $vars mapping variable name to value.
 	 */
 	public function setSchemaVars( $vars ) {
 		$this->mSchemaVars = $vars;
@@ -3194,10 +3368,10 @@ abstract class DatabaseBase implements DatabaseType {
 	 * on object's error ignore settings).
 	 *
 	 * @param $fp Resource: File handle
-	 * @param $lineCallback Callback: Optional function called before reading each line
+	 * @param $lineCallback Callback: Optional function called before reading each query
 	 * @param $resultCallback Callback: Optional function called for each MySQL result
-	 * @param $fname String: Calling function name
-	 * @param $inputCallback Callback: Optional function called for each complete line (ended with ;) sent
+	 * @param string $fname Calling function name
+	 * @param $inputCallback Callback: Optional function called for each complete query sent
 	 * @return bool|string
 	 */
 	public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
@@ -3230,20 +3404,19 @@ abstract class DatabaseBase implements DatabaseType {
 
 			if ( $done || feof( $fp ) ) {
 				$cmd = $this->replaceVars( $cmd );
-				if ( $inputCallback ) {
-					call_user_func( $inputCallback, $cmd );
-				}
-				$res = $this->query( $cmd, $fname );
 
-				if ( $resultCallback ) {
-					call_user_func( $resultCallback, $res, $this );
-				}
+				if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) || !$inputCallback ) {
+					$res = $this->query( $cmd, $fname );
 
-				if ( false === $res ) {
-					$err = $this->lastError();
-					return "Query \"{$cmd}\" failed with error code \"$err\".\n";
-				}
+					if ( $resultCallback ) {
+						call_user_func( $resultCallback, $res, $this );
+					}
 
+					if ( false === $res ) {
+						$err = $this->lastError();
+						return "Query \"{$cmd}\" failed with error code \"$err\".\n";
+					}
+				}
 				$cmd = '';
 			}
 		}
@@ -3254,8 +3427,8 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Called by sourceStream() to check if we've reached a statement end
 	 *
-	 * @param $sql String SQL assembled so far
-	 * @param $newLine String New line about to be added to $sql
+	 * @param string $sql SQL assembled so far
+	 * @param string $newLine New line about to be added to $sql
 	 * @return Bool Whether $newLine contains end of the statement
 	 */
 	public function streamStatementEnd( &$sql, &$newLine ) {
@@ -3283,7 +3456,7 @@ abstract class DatabaseBase implements DatabaseType {
 	 * - / *$var* / is just encoded, besides traditional table prefix and
 	 *   table options its use should be avoided.
 	 *
-	 * @param $ins String: SQL statement to replace variables in
+	 * @param string $ins SQL statement to replace variables in
 	 * @return String The new SQL statement with variables replaced
 	 */
 	protected function replaceSchemaVars( $ins ) {
@@ -3294,7 +3467,7 @@ abstract class DatabaseBase implements DatabaseType {
 			// replace `{$var}`
 			$ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
 			// replace /*$var*/
-			$ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
+			$ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ), $ins );
 		}
 		return $ins;
 	}
@@ -3371,8 +3544,8 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Check to see if a named lock is available. This is non-blocking.
 	 *
-	 * @param $lockName String: name of lock to poll
-	 * @param $method String: name of method calling us
+	 * @param string $lockName name of lock to poll
+	 * @param string $method name of method calling us
 	 * @return Boolean
 	 * @since 1.20
 	 */
@@ -3386,8 +3559,8 @@ abstract class DatabaseBase implements DatabaseType {
 	 * Abstracted from Filestore::lock() so child classes can implement for
 	 * their own needs.
 	 *
-	 * @param $lockName String: name of lock to aquire
-	 * @param $method String: name of method calling us
+	 * @param string $lockName name of lock to aquire
+	 * @param string $method name of method calling us
 	 * @param $timeout Integer: timeout
 	 * @return Boolean
 	 */
@@ -3398,8 +3571,8 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Release a lock.
 	 *
-	 * @param $lockName String: Name of lock to release
-	 * @param $method String: Name of method calling us
+	 * @param string $lockName Name of lock to release
+	 * @param string $method Name of method calling us
 	 *
 	 * @return int Returns 1 if the lock was released, 0 if the lock was not established
 	 * by this thread (in which case the lock is not released), and NULL if the named
@@ -3412,10 +3585,10 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Lock specific tables
 	 *
-	 * @param $read Array of tables to lock for read access
-	 * @param $write Array of tables to lock for write access
-	 * @param $method String name of caller
-	 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
+	 * @param array $read of tables to lock for read access
+	 * @param array $write of tables to lock for write access
+	 * @param string $method name of caller
+	 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
 	 *
 	 * @return bool
 	 */
@@ -3426,7 +3599,7 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Unlock specific tables
 	 *
-	 * @param $method String the caller
+	 * @param string $method the caller
 	 *
 	 * @return bool
 	 */
@@ -3476,7 +3649,7 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Encode an expiry time into the DBMS dependent format
 	 *
-	 * @param $expiry String: timestamp for expiry, or the 'infinity' string
+	 * @param string $expiry timestamp for expiry, or the 'infinity' string
 	 * @return String
 	 */
 	public function encodeExpiry( $expiry ) {
@@ -3488,7 +3661,7 @@ abstract class DatabaseBase implements DatabaseType {
 	/**
 	 * Decode an expiry time into a DBMS independent format
 	 *
-	 * @param $expiry String: DB timestamp field value for expiry
+	 * @param string $expiry DB timestamp field value for expiry
 	 * @param $format integer: TS_* constant, defaults to TS_MW
 	 * @return String
 	 */
diff --git a/includes/db/DatabaseError.php b/includes/db/DatabaseError.php
index a53a6747..628a2afc 100644
--- a/includes/db/DatabaseError.php
+++ b/includes/db/DatabaseError.php
@@ -35,9 +35,9 @@ class DBError extends MWException {
 	/**
 	 * Construct a database error
 	 * @param $db DatabaseBase object which threw the error
-	 * @param $error String A simple error message to be used for debugging
+	 * @param string $error A simple error message to be used for debugging
 	 */
-	function __construct( DatabaseBase &$db, $error ) {
+	function __construct( DatabaseBase $db = null, $error ) {
 		$this->db = $db;
 		parent::__construct( $error );
 	}
@@ -91,7 +91,7 @@ class DBError extends MWException {
 class DBConnectionError extends DBError {
 	public $error;
 
-	function __construct( DatabaseBase &$db, $error = 'unknown error' ) {
+	function __construct( DatabaseBase $db = null, $error = 'unknown error' ) {
 		$msg = 'DB connection error';
 
 		if ( trim( $error ) != '' ) {
@@ -153,12 +153,12 @@ class DBConnectionError extends DBError {
 
 		$sorry = htmlspecialchars( $this->msg( 'dberr-problems', 'Sorry! This site is experiencing technical difficulties.' ) );
 		$again = htmlspecialchars( $this->msg( 'dberr-again', 'Try waiting a few minutes and reloading.' ) );
-		$info  = htmlspecialchars( $this->msg( 'dberr-info', '(Can\'t contact the database server: $1)' ) );
+		$info = htmlspecialchars( $this->msg( 'dberr-info', '(Can\'t contact the database server: $1)' ) );
 
 		# No database access
 		MessageCache::singleton()->disable();
 
-		if ( trim( $this->error ) == '' ) {
+		if ( trim( $this->error ) == '' && $this->db ) {
 			$this->error = $this->db->getProperty( 'mServer' );
 		}
 
@@ -176,7 +176,7 @@ class DBConnectionError extends DBError {
 		return "$text<hr />$extra";
 	}
 
-	public function reportHTML(){
+	public function reportHTML() {
 		global $wgUseFileCache;
 
 		# Check whether we can serve a file-cached copy of the page with the error underneath
@@ -288,11 +288,11 @@ class DBQueryError extends DBError {
 	 * @param $sql string
 	 * @param $fname string
 	 */
-	function __construct( DatabaseBase &$db, $error, $errno, $sql, $fname ) {
-		$message = "A database error has occurred.  Did you forget to run maintenance/update.php after upgrading?  See: https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
-		  "Query: $sql\n" .
-		  "Function: $fname\n" .
-		  "Error: $errno $error\n";
+	function __construct( DatabaseBase $db, $error, $errno, $sql, $fname ) {
+		$message = "A database error has occurred. Did you forget to run maintenance/update.php after upgrading?  See: https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
+			"Query: $sql\n" .
+			"Function: $fname\n" .
+			"Error: $errno $error\n";
 		parent::__construct( $db, $message );
 
 		$this->error = $error;
diff --git a/includes/db/DatabaseIbm_db2.php b/includes/db/DatabaseIbm_db2.php
deleted file mode 100644
index f1f6dfca..00000000
--- a/includes/db/DatabaseIbm_db2.php
+++ /dev/null
@@ -1,1721 +0,0 @@
-<?php
-/**
- * This is the IBM DB2 database abstraction layer.
- * See maintenance/ibm_db2/README for development notes
- * and other specific information.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- * @ingroup Database
- * @author leo.petr+mediawiki@gmail.com
- */
-
-/**
- * This represents a column in a DB2 database
- * @ingroup Database
- */
-class IBM_DB2Field implements Field {
-	private $name = '';
-	private $tablename = '';
-	private $type = '';
-	private $nullable = false;
-	private $max_length = 0;
-
-	/**
-	 * Builder method for the class
-	 * @param $db DatabaseIbm_db2: Database interface
-	 * @param $table String: table name
-	 * @param $field String: column name
-	 * @return IBM_DB2Field
-	 */
-	static function fromText( $db, $table, $field ) {
-		global $wgDBmwschema;
-
-		$q = <<<SQL
-SELECT
-lcase( coltype ) AS typname,
-nulls AS attnotnull, length AS attlen
-FROM sysibm.syscolumns
-WHERE tbcreator=%s AND tbname=%s AND name=%s;
-SQL;
-		$res = $db->query(
-			sprintf( $q,
-				$db->addQuotes( $wgDBmwschema ),
-				$db->addQuotes( $table ),
-				$db->addQuotes( $field )
-			)
-		);
-		$row = $db->fetchObject( $res );
-		if ( !$row ) {
-			return null;
-		}
-		$n = new IBM_DB2Field;
-		$n->type = $row->typname;
-		$n->nullable = ( $row->attnotnull == 'N' );
-		$n->name = $field;
-		$n->tablename = $table;
-		$n->max_length = $row->attlen;
-		return $n;
-	}
-	/**
-	 * Get column name
-	 * @return string column name
-	 */
-	function name() { return $this->name; }
-	/**
-	 * Get table name
-	 * @return string table name
-	 */
-	function tableName() { return $this->tablename; }
-	/**
-	 * Get column type
-	 * @return string column type
-	 */
-	function type() { return $this->type; }
-	/**
-	 * Can column be null?
-	 * @return bool true or false
-	 */
-	function isNullable() { return $this->nullable; }
-	/**
-	 * How much can you fit in the column per row?
-	 * @return int length
-	 */
-	function maxLength() { return $this->max_length; }
-}
-
-/**
- * Wrapper around binary large objects
- * @ingroup Database
- */
-class IBM_DB2Blob {
-	private $mData;
-
-	public function __construct( $data ) {
-		$this->mData = $data;
-	}
-
-	public function getData() {
-		return $this->mData;
-	}
-
-	public function __toString() {
-		return $this->mData;
-	}
-}
-
-/**
- * Wrapper to address lack of certain operations in the DB2 driver
- *  ( seek, num_rows )
- * @ingroup Database
- * @since 1.19
- */
-class IBM_DB2Result{
-	private $db;
-	private $result;
-	private $num_rows;
-	private $current_pos;
-	private $columns = array();
-	private $sql;
-
-	private $resultSet = array();
-	private $loadedLines = 0;
-
-	/**
-	 * Construct and initialize a wrapper for DB2 query results
-	 * @param $db DatabaseBase
-	 * @param $result Object
-	 * @param $num_rows Integer
-	 * @param $sql String
-	 * @param $columns Array
-	 */
-	public function __construct( $db, $result, $num_rows, $sql, $columns ){
-		$this->db = $db;
-
-		if( $result instanceof ResultWrapper ){
-			$this->result = $result->result;
-		}
-		else{
-			$this->result = $result;
-		}
-
-		$this->num_rows = $num_rows;
-		$this->current_pos = 0;
-		if ( $this->num_rows > 0 ) {
-			// Make a lower-case list of the column names
-			// By default, DB2 column names are capitalized
-			//  while MySQL column names are lowercase
-
-			// Is there a reasonable maximum value for $i?
-			// Setting to 2048 to prevent an infinite loop
-			for( $i = 0; $i < 2048; $i++ ) {
-				$name = db2_field_name( $this->result, $i );
-				if ( $name != false ) {
-					continue;
-				}
-				else {
-					return false;
-				}
-
-				$this->columns[$i] = strtolower( $name );
-			}
-		}
-
-		$this->sql = $sql;
-	}
-
-	/**
-	 * Unwrap the DB2 query results
-	 * @return mixed Object on success, false on failure
-	 */
-	public function getResult() {
-		if ( $this->result ) {
-			return $this->result;
-		}
-		else return false;
-	}
-
-	/**
-	 * Get the number of rows in the result set
-	 * @return integer
-	 */
-	public function getNum_rows() {
-		return $this->num_rows;
-	}
-
-	/**
-	 * Return a row from the result set in object format
-	 * @return mixed Object on success, false on failure.
-	 */
-	public function fetchObject() {
-		if ( $this->result
-				&& $this->num_rows > 0
-				&& $this->current_pos >= 0
-				&& $this->current_pos < $this->num_rows )
-		{
-			$row = $this->fetchRow();
-			$ret = new stdClass();
-
-			foreach ( $row as $k => $v ) {
-				$lc = $this->columns[$k];
-				$ret->$lc = $v;
-			}
-			return $ret;
-		}
-		return false;
-	}
-
-	/**
-	 * Return a row form the result set in array format
-	 * @return mixed Array on success, false on failure
-	 * @throws DBUnexpectedError
-	 */
-	public function fetchRow(){
-		if ( $this->result
-				&& $this->num_rows > 0
-				&& $this->current_pos >= 0
-				&& $this->current_pos < $this->num_rows )
-		{
-			if ( $this->loadedLines <= $this->current_pos ) {
-				$row = db2_fetch_array( $this->result );
-				$this->resultSet[$this->loadedLines++] = $row;
-				if ( $this->db->lastErrno() ) {
-					throw new DBUnexpectedError( $this->db, 'Error in fetchRow(): '
-						. htmlspecialchars( $this->db->lastError() ) );
-				}
-			}
-
-			if ( $this->loadedLines > $this->current_pos ){
-				return $this->resultSet[$this->current_pos++];
-			}
-
-		}
-		return false;
-	}
-
-	/**
-	 * Free a DB2 result object
-	 * @throws DBUnexpectedError
-	 */
-	public function freeResult(){
-		unset( $this->resultSet );
-		if ( !@db2_free_result( $this->result ) ) {
-			throw new DBUnexpectedError( $this, "Unable to free DB2 result\n" );
-		}
-	}
-}
-
-/**
- * Primary database interface
- * @ingroup Database
- */
-class DatabaseIbm_db2 extends DatabaseBase {
-	/*
-	 * Inherited members
-	protected $mLastQuery = '';
-	protected $mPHPError = false;
-
-	protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
-	protected $mOpened = false;
-
-	protected $mTablePrefix;
-	protected $mFlags;
-	protected $mTrxLevel = 0;
-	protected $mErrorCount = 0;
-	protected $mLBInfo = array();
-	protected $mFakeSlaveLag = null, $mFakeMaster = false;
-	 *
-	 */
-
-	/** Database server port */
-	protected $mPort = null;
-	/** Schema for tables, stored procedures, triggers */
-	protected $mSchema = null;
-	/** Whether the schema has been applied in this session */
-	protected $mSchemaSet = false;
-	/** Result of last query */
-	protected $mLastResult = null;
-	/** Number of rows affected by last INSERT/UPDATE/DELETE */
-	protected $mAffectedRows = null;
-	/** Number of rows returned by last SELECT */
-	protected $mNumRows = null;
-	/** Current row number on the cursor of the last SELECT */
-	protected $currentRow = 0;
-
-	/** Connection config options - see constructor */
-	public $mConnOptions = array();
-	/** Statement config options -- see constructor */
-	public $mStmtOptions = array();
-
-	/** Default schema */
-	const USE_GLOBAL = 'get from global';
-
-	/** Option that applies to nothing */
-	const NONE_OPTION = 0x00;
-	/** Option that applies to connection objects */
-	const CONN_OPTION = 0x01;
-	/** Option that applies to statement objects */
-	const STMT_OPTION = 0x02;
-
-	/** Regular operation mode -- minimal debug messages */
-	const REGULAR_MODE = 'regular';
-	/** Installation mode -- lots of debug messages */
-	const INSTALL_MODE = 'install';
-
-	/** Controls the level of debug message output */
-	protected $mMode = self::REGULAR_MODE;
-
-	/** Last sequence value used for a primary key */
-	protected $mInsertId = null;
-
-	######################################
-	# Getters and Setters
-	######################################
-
-	/**
-	 * Returns true if this database supports (and uses) cascading deletes
-	 * @return bool
-	 */
-	function cascadingDeletes() {
-		return true;
-	}
-
-	/**
-	 * Returns true if this database supports (and uses) triggers (e.g. on the
-	 *  page table)
-	 * @return bool
-	 */
-	function cleanupTriggers() {
-		return true;
-	}
-
-	/**
-	 * Returns true if this database is strict about what can be put into an
-	 *  IP field.
-	 * Specifically, it uses a NULL value instead of an empty string.
-	 * @return bool
-	 */
-	function strictIPs() {
-		return true;
-	}
-
-	/**
-	 * Returns true if this database uses timestamps rather than integers
-	 * @return bool
-	 */
-	function realTimestamps() {
-		return true;
-	}
-
-	/**
-	 * Returns true if this database does an implicit sort when doing GROUP BY
-	 * @return bool
-	 */
-	function implicitGroupby() {
-		return false;
-	}
-
-	/**
-	 * Returns true if this database does an implicit order by when the column
-	 *  has an index
-	 * For example: SELECT page_title FROM page LIMIT 1
-	 * @return bool
-	 */
-	function implicitOrderby() {
-		return false;
-	}
-
-	/**
-	 * Returns true if this database can do a native search on IP columns
-	 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
-	 * @return bool
-	 */
-	function searchableIPs() {
-		return true;
-	}
-
-	/**
-	 * Returns true if this database can use functional indexes
-	 * @return bool
-	 */
-	function functionalIndexes() {
-		return true;
-	}
-
-	/**
-	 * Returns a unique string representing the wiki on the server
-	 * @return string
-	 */
-	public function getWikiID() {
-		if( $this->mSchema ) {
-			return "{$this->mDBname}-{$this->mSchema}";
-		} else {
-			return $this->mDBname;
-		}
-	}
-
-	/**
-	 * Returns the database software identifieir
-	 * @return string
-	 */
-	public function getType() {
-		return 'ibm_db2';
-	}
-
-	/**
-	 * Returns the database connection object
-	 * @return Object
-	 */
-	public function getDb(){
-		return $this->mConn;
-	}
-
-	/**
-	 *
-	 * @param $server String: hostname of database server
-	 * @param $user String: username
-	 * @param $password String: password
-	 * @param $dbName String: database name on the server
-	 * @param $flags Integer: database behaviour flags (optional, unused)
-	 * @param $schema String
-	 */
-	public function __construct( $server = false, $user = false,
-							$password = false,
-							$dbName = false, $flags = 0,
-							$schema = self::USE_GLOBAL )
-	{
-		global $wgDBmwschema;
-
-		if ( $schema == self::USE_GLOBAL ) {
-			$this->mSchema = $wgDBmwschema;
-		} else {
-			$this->mSchema = $schema;
-		}
-
-		// configure the connection and statement objects
-		$this->setDB2Option( 'db2_attr_case', 'DB2_CASE_LOWER',
-			self::CONN_OPTION | self::STMT_OPTION );
-		$this->setDB2Option( 'deferred_prepare', 'DB2_DEFERRED_PREPARE_ON',
-			self::STMT_OPTION );
-		$this->setDB2Option( 'rowcount', 'DB2_ROWCOUNT_PREFETCH_ON',
-			self::STMT_OPTION );
-		parent::__construct( $server, $user, $password, $dbName, DBO_TRX | $flags );
-	}
-
-	/**
-	 * Enables options only if the ibm_db2 extension version supports them
-	 * @param $name String: name of the option in the options array
-	 * @param $const String: name of the constant holding the right option value
-	 * @param $type Integer: whether this is a Connection or Statement otion
-	 */
-	private function setDB2Option( $name, $const, $type ) {
-		if ( defined( $const ) ) {
-			if ( $type & self::CONN_OPTION ) {
-				$this->mConnOptions[$name] = constant( $const );
-			}
-			if ( $type & self::STMT_OPTION ) {
-				$this->mStmtOptions[$name] = constant( $const );
-			}
-		} else {
-			$this->installPrint(
-				"$const is not defined. ibm_db2 version is likely too low." );
-		}
-	}
-
-	/**
-	 * Outputs debug information in the appropriate place
-	 * @param $string String: the relevant debug message
-	 */
-	private function installPrint( $string ) {
-		wfDebug( "$string\n" );
-		if ( $this->mMode == self::INSTALL_MODE ) {
-			print "<li><pre>$string</pre></li>";
-			flush();
-		}
-	}
-
-	/**
-	 * Opens a database connection and returns it
-	 * Closes any existing connection
-	 *
-	 * @param $server String: hostname
-	 * @param $user String
-	 * @param $password String
-	 * @param $dbName String: database name
-	 * @return DatabaseBase a fresh connection
-	 */
-	public function open( $server, $user, $password, $dbName ) {
-		wfProfileIn( __METHOD__ );
-
-		# Load IBM DB2 driver if missing
-		wfDl( 'ibm_db2' );
-
-		# Test for IBM DB2 support, to avoid suppressed fatal error
-		if ( !function_exists( 'db2_connect' ) ) {
-			throw new DBConnectionError( $this, "DB2 functions missing, have you enabled the ibm_db2 extension for PHP?" );
-		}
-
-		global $wgDBport;
-
-		// Close existing connection
-		$this->close();
-		// Cache conn info
-		$this->mServer = $server;
-		$this->mPort = $port = $wgDBport;
-		$this->mUser = $user;
-		$this->mPassword = $password;
-		$this->mDBname = $dbName;
-
-		$this->openUncataloged( $dbName, $user, $password, $server, $port );
-
-		if ( !$this->mConn ) {
-			$this->installPrint( "DB connection error\n" );
-			$this->installPrint(
-				"Server: $server, Database: $dbName, User: $user, Password: "
-				. substr( $password, 0, 3 ) . "...\n" );
-			$this->installPrint( $this->lastError() . "\n" );
-			wfProfileOut( __METHOD__ );
-			wfDebug( "DB connection error\n" );
-			wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
-			wfDebug( $this->lastError() . "\n" );
-			throw new DBConnectionError( $this, $this->lastError() );
-		}
-
-		// Some MediaWiki code is still transaction-less (?).
-		// The strategy is to keep AutoCommit on for that code
-		//  but switch it off whenever a transaction is begun.
-		db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_ON );
-
-		$this->mOpened = true;
-		$this->applySchema();
-
-		wfProfileOut( __METHOD__ );
-		return $this->mConn;
-	}
-
-	/**
-	 * Opens a cataloged database connection, sets mConn
-	 */
-	protected function openCataloged( $dbName, $user, $password ) {
-		wfSuppressWarnings();
-		$this->mConn = db2_pconnect( $dbName, $user, $password );
-		wfRestoreWarnings();
-	}
-
-	/**
-	 * Opens an uncataloged database connection, sets mConn
-	 */
-	protected function openUncataloged( $dbName, $user, $password, $server, $port )
-	{
-		$dsn = "DRIVER={IBM DB2 ODBC DRIVER};DATABASE=$dbName;CHARSET=UTF-8;HOSTNAME=$server;PORT=$port;PROTOCOL=TCPIP;UID=$user;PWD=$password;";
-		wfSuppressWarnings();
-		$this->mConn = db2_pconnect( $dsn, "", "", array() );
-		wfRestoreWarnings();
-	}
-
-	/**
-	 * Closes a database connection, if it is open
-	 * Returns success, true if already closed
-	 * @return bool
-	 */
-	protected function closeConnection() {
-		return db2_close( $this->mConn );
-	}
-
-	/**
-	 * Retrieves the most current database error
-	 * Forces a database rollback
-	 * @return bool|string
-	 */
-	public function lastError() {
-		$connerr = db2_conn_errormsg();
-		if ( $connerr ) {
-			//$this->rollback( __METHOD__ );
-			return $connerr;
-		}
-		$stmterr = db2_stmt_errormsg();
-		if ( $stmterr ) {
-			//$this->rollback( __METHOD__ );
-			return $stmterr;
-		}
-
-		return false;
-	}
-
-	/**
-	 * Get the last error number
-	 * Return 0 if no error
-	 * @return integer
-	 */
-	public function lastErrno() {
-		$connerr = db2_conn_error();
-		if ( $connerr ) {
-			return $connerr;
-		}
-		$stmterr = db2_stmt_error();
-		if ( $stmterr ) {
-			return $stmterr;
-		}
-		return 0;
-	}
-
-	/**
-	 * Is a database connection open?
-	 * @return
-	 */
-	public function isOpen() { return $this->mOpened; }
-
-	/**
-	 * The DBMS-dependent part of query()
-	 * @param  $sql String: SQL query.
-	 * @return object Result object for fetch functions or false on failure
-	 */
-	protected function doQuery( $sql ) {
-		$this->applySchema();
-
-		// Needed to handle any UTF-8 encoding issues in the raw sql
-		// Note that we fully support prepared statements for DB2
-		// prepare() and execute() should be used instead of doQuery() whenever possible
-		$sql = utf8_decode( $sql );
-
-		$ret = db2_exec( $this->mConn, $sql, $this->mStmtOptions );
-		if( $ret == false ) {
-			$error = db2_stmt_errormsg();
-
-			$this->installPrint( "<pre>$sql</pre>" );
-			$this->installPrint( $error );
-			throw new DBUnexpectedError( $this, 'SQL error: '
-				. htmlspecialchars( $error ) );
-		}
-		$this->mLastResult = $ret;
-		$this->mAffectedRows = null; // Not calculated until asked for
-		return $ret;
-	}
-
-	/**
-	 * @return string Version information from the database
-	 */
-	public function getServerVersion() {
-		$info = db2_server_info( $this->mConn );
-		return $info->DBMS_VER;
-	}
-
-	/**
-	 * Queries whether a given table exists
-	 * @return boolean
-	 */
-	public function tableExists( $table, $fname = __METHOD__ ) {
-		$schema = $this->mSchema;
-
-		$sql = "SELECT COUNT( * ) FROM SYSIBM.SYSTABLES ST WHERE ST.NAME = '" .
-			strtoupper( $table ) .
-			"' AND ST.CREATOR = '" .
-			strtoupper( $schema ) . "'";
-		$res = $this->query( $sql );
-		if ( !$res ) {
-			return false;
-		}
-
-		// If the table exists, there should be one of it
-		$row = $this->fetchRow( $res );
-		$count = $row[0];
-		if ( $count == '1' || $count == 1 ) {
-			return true;
-		}
-
-		return false;
-	}
-
-	/**
-	 * Fetch the next row from the given result object, in object form.
-	 * Fields can be retrieved with $row->fieldname, with fields acting like
-	 * member variables.
-	 *
-	 * @param $res array|ResultWrapper SQL result object as returned from Database::query(), etc.
-	 * @return DB2 row object
-	 * @throws DBUnexpectedError Thrown if the database returns an error
-	 */
-	public function fetchObject( $res ) {
-		if ( $res instanceof ResultWrapper ) {
-			$res = $res->result;
-		}
-		wfSuppressWarnings();
-		$row = db2_fetch_object( $res );
-		wfRestoreWarnings();
-		if( $this->lastErrno() ) {
-			throw new DBUnexpectedError( $this, 'Error in fetchObject(): '
-				. htmlspecialchars( $this->lastError() ) );
-		}
-		return $row;
-	}
-
-	/**
-	 * Fetch the next row from the given result object, in associative array
-	 * form. Fields are retrieved with $row['fieldname'].
-	 *
-	 * @param $res array|ResultWrapper SQL result object as returned from Database::query(), etc.
-	 * @return ResultWrapper row object
-	 * @throws DBUnexpectedError Thrown if the database returns an error
-	 */
-	public function fetchRow( $res ) {
-		if ( $res instanceof ResultWrapper ) {
-			$res = $res->result;
-		}
-		if ( db2_num_rows( $res ) > 0) {
-			wfSuppressWarnings();
-			$row = db2_fetch_array( $res );
-			wfRestoreWarnings();
-			if ( $this->lastErrno() ) {
-				throw new DBUnexpectedError( $this, 'Error in fetchRow(): '
-					. htmlspecialchars( $this->lastError() ) );
-			}
-			return $row;
-		}
-		return false;
-	}
-
-	/**
-	 * Escapes strings
-	 * Doesn't escape numbers
-	 *
-	 * @param $s String: string to escape
-	 * @return string escaped string
-	 */
-	public function addQuotes( $s ) {
-		//$this->installPrint( "DB2::addQuotes( $s )\n" );
-		if ( is_null( $s ) ) {
-			return 'NULL';
-		} elseif ( $s instanceof Blob ) {
-			return "'" . $s->fetch( $s ) . "'";
-		} elseif ( $s instanceof IBM_DB2Blob ) {
-			return "'" . $this->decodeBlob( $s ) . "'";
-		}
-		$s = $this->strencode( $s );
-		if ( is_numeric( $s ) ) {
-			return $s;
-		} else {
-			return "'$s'";
-		}
-	}
-
-	/**
-	 * Verifies that a DB2 column/field type is numeric
-	 *
-	 * @param $type String: DB2 column type
-	 * @return Boolean: true if numeric
-	 */
-	public function is_numeric_type( $type ) {
-		switch ( strtoupper( $type ) ) {
-			case 'SMALLINT':
-			case 'INTEGER':
-			case 'INT':
-			case 'BIGINT':
-			case 'DECIMAL':
-			case 'REAL':
-			case 'DOUBLE':
-			case 'DECFLOAT':
-				return true;
-		}
-		return false;
-	}
-
-	/**
-	 * Alias for addQuotes()
-	 * @param $s String: string to escape
-	 * @return string escaped string
-	 */
-	public function strencode( $s ) {
-		// Bloody useless function
-		//  Prepends backslashes to \x00, \n, \r, \, ', " and \x1a.
-		//  But also necessary
-		$s = db2_escape_string( $s );
-		// Wide characters are evil -- some of them look like '
-		$s = utf8_encode( $s );
-		// Fix its stupidity
-		$from =	array( 	"\\\\",	"\\'",	'\\n',	'\\t',	'\\"',	'\\r' );
-		$to = array( 		"\\",		"''",		"\n",		"\t",		'"',		"\r" );
-		$s = str_replace( $from, $to, $s ); // DB2 expects '', not \' escaping
-		return $s;
-	}
-
-	/**
-	 * Switch into the database schema
-	 */
-	protected function applySchema() {
-		if ( !( $this->mSchemaSet ) ) {
-			$this->mSchemaSet = true;
-			$this->begin( __METHOD__ );
-			$this->doQuery( "SET SCHEMA = $this->mSchema" );
-			$this->commit( __METHOD__ );
-		}
-	}
-
-	/**
-	 * Start a transaction (mandatory)
-	 */
-	protected function doBegin( $fname = 'DatabaseIbm_db2::begin' ) {
-		// BEGIN is implicit for DB2
-		// However, it requires that AutoCommit be off.
-
-		// Some MediaWiki code is still transaction-less (?).
-		// The strategy is to keep AutoCommit on for that code
-		//  but switch it off whenever a transaction is begun.
-		db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_OFF );
-
-		$this->mTrxLevel = 1;
-	}
-
-	/**
-	 * End a transaction
-	 * Must have a preceding begin()
-	 */
-	protected function doCommit( $fname = 'DatabaseIbm_db2::commit' ) {
-		db2_commit( $this->mConn );
-
-		// Some MediaWiki code is still transaction-less (?).
-		// The strategy is to keep AutoCommit on for that code
-		//  but switch it off whenever a transaction is begun.
-		db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_ON );
-
-		$this->mTrxLevel = 0;
-	}
-
-	/**
-	 * Cancel a transaction
-	 */
-	protected function doRollback( $fname = 'DatabaseIbm_db2::rollback' ) {
-		db2_rollback( $this->mConn );
-		// turn auto-commit back on
-		// not sure if this is appropriate
-		db2_autocommit( $this->mConn, DB2_AUTOCOMMIT_ON );
-		$this->mTrxLevel = 0;
-	}
-
-	/**
-	 * Makes an encoded list of strings from an array
-	 * $mode:
-	 *   LIST_COMMA         - comma separated, no field names
-	 *   LIST_AND           - ANDed WHERE clause (without the WHERE)
-	 *   LIST_OR            - ORed WHERE clause (without the WHERE)
-	 *   LIST_SET           - comma separated with field names, like a SET clause
-	 *   LIST_NAMES         - comma separated field names
-	 *   LIST_SET_PREPARED  - like LIST_SET, except with ? tokens as values
-	 * @return string
-	 */
-	function makeList( $a, $mode = LIST_COMMA ) {
-		if ( !is_array( $a ) ) {
-			throw new DBUnexpectedError( $this,
-				'DatabaseIbm_db2::makeList called with incorrect parameters' );
-		}
-
-		// if this is for a prepared UPDATE statement
-		// (this should be promoted to the parent class
-		//  once other databases use prepared statements)
-		if ( $mode == LIST_SET_PREPARED ) {
-			$first = true;
-			$list = '';
-			foreach ( $a as $field => $value ) {
-				if ( !$first ) {
-					$list .= ", $field = ?";
-				} else {
-					$list .= "$field = ?";
-					$first = false;
-				}
-			}
-			$list .= '';
-
-			return $list;
-		}
-
-		// otherwise, call the usual function
-		return parent::makeList( $a, $mode );
-	}
-
-	/**
-	 * Construct a LIMIT query with optional offset
-	 * This is used for query pages
-	 *
-	 * @param $sql string SQL query we will append the limit too
-	 * @param $limit integer the SQL limit
-	 * @param $offset integer the SQL offset (default false)
-	 * @return string
-	 */
-	public function limitResult( $sql, $limit, $offset=false ) {
-		if( !is_numeric( $limit ) ) {
-			throw new DBUnexpectedError( $this,
-				"Invalid non-numeric limit passed to limitResult()\n" );
-		}
-		if( $offset ) {
-			if ( stripos( $sql, 'where' ) === false ) {
-				return "$sql AND ( ROWNUM BETWEEN $offset AND $offset+$limit )";
-			} else {
-				return "$sql WHERE ( ROWNUM BETWEEN $offset AND $offset+$limit )";
-			}
-		}
-		return "$sql FETCH FIRST $limit ROWS ONLY ";
-	}
-
-	/**
-	 * Handle reserved keyword replacement in table names
-	 *
-	 * @param $name Object
-	 * @param $format String Ignored parameter Default 'quoted'Boolean
-	 * @return String
-	 */
-	public function tableName( $name, $format = 'quoted' ) {
-		// we want maximum compatibility with MySQL schema
-		return $name;
-	}
-
-	/**
-	 * Generates a timestamp in an insertable format
-	 *
-	 * @param $ts string timestamp
-	 * @return String: timestamp value
-	 */
-	public function timestamp( $ts = 0 ) {
-		// TS_MW cannot be easily distinguished from an integer
-		return wfTimestamp( TS_DB2, $ts );
-	}
-
-	/**
-	 * Return the next in a sequence, save the value for retrieval via insertId()
-	 * @param $seqName String: name of a defined sequence in the database
-	 * @return int next value in that sequence
-	 */
-	public function nextSequenceValue( $seqName ) {
-		// Not using sequences in the primary schema to allow for easier migration
-		//  from MySQL
-		// Emulating MySQL behaviour of using NULL to signal that sequences
-		// aren't used
-		/*
-		$safeseq = preg_replace( "/'/", "''", $seqName );
-		$res = $this->query( "VALUES NEXTVAL FOR $safeseq" );
-		$row = $this->fetchRow( $res );
-		$this->mInsertId = $row[0];
-		return $this->mInsertId;
-		*/
-		return null;
-	}
-
-	/**
-	 * This must be called after nextSequenceVal
-	 * @return int Last sequence value used as a primary key
-	 */
-	public function insertId() {
-		return $this->mInsertId;
-	}
-
-	/**
-	 * Updates the mInsertId property with the value of the last insert
-	 *  into a generated column
-	 *
-	 * @param $table      String: sanitized table name
-	 * @param $primaryKey Mixed: string name of the primary key
-	 * @param $stmt       Resource: prepared statement resource
-	 *  of the SELECT primary_key FROM FINAL TABLE ( INSERT ... ) form
-	 */
-	private function calcInsertId( $table, $primaryKey, $stmt ) {
-		if ( $primaryKey ) {
-			$this->mInsertId = db2_last_insert_id( $this->mConn );
-		}
-	}
-
-	/**
-	 * INSERT wrapper, inserts an array into a table
-	 *
-	 * $args may be a single associative array, or an array of arrays
-	 *  with numeric keys, for multi-row insert
-	 *
-	 * @param $table   String: Name of the table to insert to.
-	 * @param $args    Array: Items to insert into the table.
-	 * @param $fname   String: Name of the function, for profiling
-	 * @param $options String or Array. Valid options: IGNORE
-	 *
-	 * @return bool Success of insert operation. IGNORE always returns true.
-	 */
-	public function insert( $table, $args, $fname = 'DatabaseIbm_db2::insert',
-		$options = array() )
-	{
-		if ( !count( $args ) ) {
-			return true;
-		}
-		// get database-specific table name (not used)
-		$table = $this->tableName( $table );
-		// format options as an array
-		$options = IBM_DB2Helper::makeArray( $options );
-		// format args as an array of arrays
-		if ( !( isset( $args[0] ) && is_array( $args[0] ) ) ) {
-			$args = array( $args );
-		}
-
-		// prevent insertion of NULL into primary key columns
-		list( $args, $primaryKeys ) = $this->removeNullPrimaryKeys( $table, $args );
-		// if there's only one primary key
-		// we'll be able to read its value after insertion
-		$primaryKey = false;
-		if ( count( $primaryKeys ) == 1 ) {
-			$primaryKey = $primaryKeys[0];
-		}
-
-		// get column names
-		$keys = array_keys( $args[0] );
-		$key_count = count( $keys );
-
-		// If IGNORE is set, we use savepoints to emulate mysql's behavior
-		$ignore = in_array( 'IGNORE', $options ) ? 'mw' : '';
-
-		// assume success
-		$res = true;
-		// If we are not in a transaction, we need to be for savepoint trickery
-		if ( !$this->mTrxLevel ) {
-			$this->begin( __METHOD__ );
-		}
-
-		$sql = "INSERT INTO $table ( " . implode( ',', $keys ) . ' ) VALUES ';
-		if ( $key_count == 1 ) {
-			$sql .= '( ? )';
-		} else {
-			$sql .= '( ?' . str_repeat( ',?', $key_count-1 ) . ' )';
-		}
-		$this->installPrint( "Preparing the following SQL:" );
-		$this->installPrint( "$sql" );
-		$this->installPrint( print_r( $args, true ));
-		$stmt = $this->prepare( $sql );
-
-		// start a transaction/enter transaction mode
-		$this->begin( __METHOD__ );
-
-		if ( !$ignore ) {
-			//$first = true;
-			foreach ( $args as $row ) {
-				//$this->installPrint( "Inserting " . print_r( $row, true ));
-				// insert each row into the database
-				$res = $res & $this->execute( $stmt, $row );
-				if ( !$res ) {
-					$this->installPrint( 'Last error:' );
-					$this->installPrint( $this->lastError() );
-				}
-				// get the last inserted value into a generated column
-				$this->calcInsertId( $table, $primaryKey, $stmt );
-			}
-		} else {
-			$olde = error_reporting( 0 );
-			// For future use, we may want to track the number of actual inserts
-			// Right now, insert (all writes) simply return true/false
-			$numrowsinserted = 0;
-
-			// always return true
-			$res = true;
-
-			foreach ( $args as $row ) {
-				$overhead = "SAVEPOINT $ignore ON ROLLBACK RETAIN CURSORS";
-				db2_exec( $this->mConn, $overhead, $this->mStmtOptions );
-
-				$res2 = $this->execute( $stmt, $row );
-
-				if ( !$res2 ) {
-					$this->installPrint( 'Last error:' );
-					$this->installPrint( $this->lastError() );
-				}
-				// get the last inserted value into a generated column
-				$this->calcInsertId( $table, $primaryKey, $stmt );
-
-				$errNum = $this->lastErrno();
-				if ( $errNum ) {
-					db2_exec( $this->mConn, "ROLLBACK TO SAVEPOINT $ignore",
-						$this->mStmtOptions );
-				} else {
-					db2_exec( $this->mConn, "RELEASE SAVEPOINT $ignore",
-						$this->mStmtOptions );
-					$numrowsinserted++;
-				}
-			}
-
-			$olde = error_reporting( $olde );
-			// Set the affected row count for the whole operation
-			$this->mAffectedRows = $numrowsinserted;
-		}
-		// commit either way
-		$this->commit( __METHOD__ );
-		$this->freePrepared( $stmt );
-
-		return $res;
-	}
-
-	/**
-	 * Given a table name and a hash of columns with values
-	 * Removes primary key columns from the hash where the value is NULL
-	 *
-	 * @param $table String: name of the table
-	 * @param $args Array of hashes of column names with values
-	 * @return Array: tuple( filtered array of columns, array of primary keys )
-	 */
-	private function removeNullPrimaryKeys( $table, $args ) {
-		$schema = $this->mSchema;
-
-		// find out the primary keys
-		$keyres = $this->doQuery( "SELECT NAME FROM SYSIBM.SYSCOLUMNS WHERE TBNAME = '"
-		  . strtoupper( $table )
-		  . "' AND TBCREATOR = '"
-		  . strtoupper( $schema )
-		  . "' AND KEYSEQ > 0" );
-
-		$keys = array();
-		for (
-			$row = $this->fetchRow( $keyres );
-			$row != null;
-			$row = $this->fetchRow( $keyres )
-		)
-		{
-			$keys[] = strtolower( $row[0] );
-		}
-		// remove primary keys
-		foreach ( $args as $ai => $row ) {
-			foreach ( $keys as $key ) {
-				if ( $row[$key] == null ) {
-					unset( $row[$key] );
-				}
-			}
-			$args[$ai] = $row;
-		}
-		// return modified hash
-		return array( $args, $keys );
-	}
-
-	/**
-	 * UPDATE wrapper, takes a condition array and a SET array
-	 *
-	 * @param $table  String: The table to UPDATE
-	 * @param $values array An array of values to SET
-	 * @param $conds  array An array of conditions ( WHERE ). Use '*' to update all rows.
-	 * @param $fname  String: The Class::Function calling this function
-	 *                ( for the log )
-	 * @param $options array An array of UPDATE options, can be one or
-	 *                 more of IGNORE, LOW_PRIORITY
-	 * @return Boolean
-	 */
-	public function update( $table, $values, $conds, $fname = 'DatabaseIbm_db2::update',
-		$options = array() )
-	{
-		$table = $this->tableName( $table );
-		$opts = $this->makeUpdateOptions( $options );
-		$sql = "UPDATE $opts $table SET "
-			. $this->makeList( $values, LIST_SET_PREPARED );
-		if ( $conds != '*' ) {
-			$sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
-		}
-		$stmt = $this->prepare( $sql );
-		$this->installPrint( 'UPDATE: ' . print_r( $values, true ) );
-		// assuming for now that an array with string keys will work
-		// if not, convert to simple array first
-		$result = $this->execute( $stmt, $values );
-		$this->freePrepared( $stmt );
-
-		return $result;
-	}
-
-	/**
-	 * DELETE query wrapper
-	 *
-	 * Use $conds == "*" to delete all rows
-	 * @return bool|\ResultWrapper
-	 */
-	public function delete( $table, $conds, $fname = 'DatabaseIbm_db2::delete' ) {
-		if ( !$conds ) {
-			throw new DBUnexpectedError( $this,
-				'DatabaseIbm_db2::delete() called with no conditions' );
-		}
-		$table = $this->tableName( $table );
-		$sql = "DELETE FROM $table";
-		if ( $conds != '*' ) {
-			$sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
-		}
-		$result = $this->query( $sql, $fname );
-
-		return $result;
-	}
-
-	/**
-	 * Returns the number of rows affected by the last query or 0
-	 * @return Integer: the number of rows affected by the last query
-	 */
-	public function affectedRows() {
-		if ( !is_null( $this->mAffectedRows ) ) {
-			// Forced result for simulated queries
-			return $this->mAffectedRows;
-		}
-		if( empty( $this->mLastResult ) ) {
-			return 0;
-		}
-		return db2_num_rows( $this->mLastResult );
-	}
-
-	/**
-	 * Returns the number of rows in the result set
-	 * Has to be called right after the corresponding select query
-	 * @param $res Object result set
-	 * @return Integer: number of rows
-	 */
-	public function numRows( $res ) {
-		if ( $res instanceof ResultWrapper ) {
-			$res = $res->result;
-		}
-
-		if ( $this->mNumRows ) {
-			return $this->mNumRows;
-		} else {
-			return 0;
-		}
-	}
-
-	/**
-	 * Moves the row pointer of the result set
-	 * @param $res Object: result set
-	 * @param $row Integer: row number
-	 * @return bool success or failure
-	 */
-	public function dataSeek( $res, $row ) {
-		if ( $res instanceof ResultWrapper ) {
-			return $res = $res->result;
-		}
-		if ( $res instanceof IBM_DB2Result ) {
-			return $res->dataSeek( $row );
-		}
-		wfDebug( "dataSeek operation in DB2 database\n" );
-		return false;
-	}
-
-	###
-	# Fix notices in Block.php
-	###
-
-	/**
-	 * Frees memory associated with a statement resource
-	 * @param $res Object: statement resource to free
-	 * @return Boolean success or failure
-	 */
-	public function freeResult( $res ) {
-		if ( $res instanceof ResultWrapper ) {
-			$res = $res->result;
-		}
-		wfSuppressWarnings();
-		$ok = db2_free_result( $res );
-		wfRestoreWarnings();
-		if ( !$ok ) {
-			throw new DBUnexpectedError( $this, "Unable to free DB2 result\n" );
-		}
-	}
-
-	/**
-	 * Returns the number of columns in a resource
-	 * @param $res Object: statement resource
-	 * @return Number of fields/columns in resource
-	 */
-	public function numFields( $res ) {
-		if ( $res instanceof ResultWrapper ) {
-			$res = $res->result;
-		}
-		if ( $res instanceof IBM_DB2Result ) {
-			$res = $res->getResult();
-		}
-		return db2_num_fields( $res );
-	}
-
-	/**
-	 * Returns the nth column name
-	 * @param $res Object: statement resource
-	 * @param $n Integer: Index of field or column
-	 * @return String name of nth column
-	 */
-	public function fieldName( $res, $n ) {
-		if ( $res instanceof ResultWrapper ) {
-			$res = $res->result;
-		}
-		if ( $res instanceof IBM_DB2Result ) {
-			$res = $res->getResult();
-		}
-		return db2_field_name( $res, $n );
-	}
-
-	/**
-	 * SELECT wrapper
-	 *
-	 * @param $table   Array or string, table name(s) (prefix auto-added)
-	 * @param $vars    Array or string, field name(s) to be retrieved
-	 * @param $conds   Array or string, condition(s) for WHERE
-	 * @param $fname   String: calling function name (use __METHOD__)
-	 *                 for logs/profiling
-	 * @param $options array Associative array of options
-	 *                 (e.g. array( 'GROUP BY' => 'page_title' )),
-	 *                 see Database::makeSelectOptions code for list of
-	 *                 supported stuff
-	 * @param $join_conds array Associative array of table join conditions (optional)
-	 *                    (e.g. array( 'page' => array('LEFT JOIN',
-	 *                    'page_latest=rev_id') )
-	 * @return Mixed: database result resource for fetch functions or false
-	 *                 on failure
-	 */
-	public function select( $table, $vars, $conds = '', $fname = 'DatabaseIbm_db2::select', $options = array(), $join_conds = array() )
-	{
-		$res = parent::select( $table, $vars, $conds, $fname, $options,
-			$join_conds );
-		$sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
-
-		// We must adjust for offset
-		if ( isset( $options['LIMIT'] ) && isset ( $options['OFFSET'] ) ) {
-			$limit = $options['LIMIT'];
-			$offset = $options['OFFSET'];
-		}
-
-		// DB2 does not have a proper num_rows() function yet, so we must emulate
-		// DB2 9.5.4 and the corresponding ibm_db2 driver will introduce
-		//  a working one
-		// TODO: Yay!
-
-		// we want the count
-		$vars2 = array( 'count( * ) as num_rows' );
-		// respecting just the limit option
-		$options2 = array();
-		if ( isset( $options['LIMIT'] ) ) {
-			$options2['LIMIT'] = $options['LIMIT'];
-		}
-		// but don't try to emulate for GROUP BY
-		if ( isset( $options['GROUP BY'] ) ) {
-			return $res;
-		}
-
-		$res2 = parent::select( $table, $vars2, $conds, $fname, $options2,
-			$join_conds );
-
-		$obj = $this->fetchObject( $res2 );
-		$this->mNumRows = $obj->num_rows;
-
-		return new ResultWrapper( $this, new IBM_DB2Result( $this, $res, $obj->num_rows, $vars, $sql ) );
-	}
-
-	/**
-	 * Handles ordering, grouping, and having options ('GROUP BY' => colname)
-	 * Has limited support for per-column options (colnum => 'DISTINCT')
-	 *
-	 * @private
-	 *
-	 * @param $options array Associative array of options to be turned into
-	 *              an SQL query, valid keys are listed in the function.
-	 * @return Array
-	 */
-	function makeSelectOptions( $options ) {
-		$preLimitTail = $postLimitTail = '';
-		$startOpts = '';
-
-		$noKeyOptions = array();
-		foreach ( $options as $key => $option ) {
-			if ( is_numeric( $key ) ) {
-				$noKeyOptions[$option] = true;
-			}
-		}
-
-		if ( isset( $options['GROUP BY'] ) ) {
-			$preLimitTail .= " GROUP BY {$options['GROUP BY']}";
-		}
-		if ( isset( $options['HAVING'] ) ) {
-			$preLimitTail .= " HAVING {$options['HAVING']}";
-		}
-		if ( isset( $options['ORDER BY'] ) ) {
-			$preLimitTail .= " ORDER BY {$options['ORDER BY']}";
-		}
-
-		if ( isset( $noKeyOptions['DISTINCT'] )
-			|| isset( $noKeyOptions['DISTINCTROW'] ) )
-		{
-			$startOpts .= 'DISTINCT';
-		}
-
-		return array( $startOpts, '', $preLimitTail, $postLimitTail );
-	}
-
-	/**
-	 * Returns link to IBM DB2 free download
-	 * @return String: wikitext of a link to the server software's web site
-	 */
-	public static function getSoftwareLink() {
-		return '[http://www.ibm.com/db2/express/ IBM DB2]';
-	}
-
-	/**
-	 * Get search engine class. All subclasses of this
-	 * need to implement this if they wish to use searching.
-	 *
-	 * @return String
-	 */
-	public function getSearchEngine() {
-		return 'SearchIBM_DB2';
-	}
-
-	/**
-	 * Did the last database access fail because of deadlock?
-	 * @return Boolean
-	 */
-	public function wasDeadlock() {
-		// get SQLSTATE
-		$err = $this->lastErrno();
-		switch( $err ) {
-			// This is literal port of the MySQL logic and may be wrong for DB2
-			case '40001':	// sql0911n, Deadlock or timeout, rollback
-			case '57011':	// sql0904n, Resource unavailable, no rollback
-			case '57033':	// sql0913n, Deadlock or timeout, no rollback
-			$this->installPrint( "In a deadlock because of SQLSTATE $err" );
-			return true;
-		}
-		return false;
-	}
-
-	/**
-	 * Ping the server and try to reconnect if it there is no connection
-	 * The connection may be closed and reopened while this happens
-	 * @return Boolean: whether the connection exists
-	 */
-	public function ping() {
-		// db2_ping() doesn't exist
-		// Emulate
-		$this->close();
-		$this->openUncataloged( $this->mDBName, $this->mUser,
-			$this->mPassword, $this->mServer, $this->mPort );
-
-		return false;
-	}
-	######################################
-	# Unimplemented and not applicable
-	######################################
-
-	/**
-	 * Only useful with fake prepare like in base Database class
-	 * @return	string
-	 */
-	public function fillPreparedArg( $matches ) {
-		$this->installPrint( 'Not useful for DB2: fillPreparedArg()' );
-		return '';
-	}
-
-	######################################
-	# Reflection
-	######################################
-
-	/**
-	 * Returns information about an index
-	 * If errors are explicitly ignored, returns NULL on failure
-	 * @param $table String: table name
-	 * @param $index String: index name
-	 * @param $fname String: function name for logging and profiling
-	 * @return Object query row in object form
-	 */
-	public function indexInfo( $table, $index,
-		$fname = 'DatabaseIbm_db2::indexExists' )
-	{
-		$table = $this->tableName( $table );
-		$sql = <<<SQL
-SELECT name as indexname
-FROM sysibm.sysindexes si
-WHERE si.name='$index' AND si.tbname='$table'
-AND sc.tbcreator='$this->mSchema'
-SQL;
-		$res = $this->query( $sql, $fname );
-		if ( !$res ) {
-			return null;
-		}
-		$row = $this->fetchObject( $res );
-		if ( $row != null ) {
-			return $row;
-		} else {
-			return false;
-		}
-	}
-
-	/**
-	 * Returns an information object on a table column
-	 * @param $table String: table name
-	 * @param $field String: column name
-	 * @return IBM_DB2Field
-	 */
-	public function fieldInfo( $table, $field ) {
-		return IBM_DB2Field::fromText( $this, $table, $field );
-	}
-
-	/**
-	 * db2_field_type() wrapper
-	 * @param $res Object: result of executed statement
-	 * @param $index Mixed: number or name of the column
-	 * @return String column type
-	 */
-	public function fieldType( $res, $index ) {
-		if ( $res instanceof ResultWrapper ) {
-			$res = $res->result;
-		}
-		if ( $res instanceof IBM_DB2Result ) {
-			$res = $res->getResult();
-		}
-		return db2_field_type( $res, $index );
-	}
-
-	/**
-	 * Verifies that an index was created as unique
-	 * @param $table String: table name
-	 * @param $index String: index name
-	 * @param $fname string function name for profiling
-	 * @return Bool
-	 */
-	public function indexUnique ( $table, $index,
-		$fname = 'DatabaseIbm_db2::indexUnique' )
-	{
-		$table = $this->tableName( $table );
-		$sql = <<<SQL
-SELECT si.name as indexname
-FROM sysibm.sysindexes si
-WHERE si.name='$index' AND si.tbname='$table'
-AND sc.tbcreator='$this->mSchema'
-AND si.uniquerule IN ( 'U', 'P' )
-SQL;
-		$res = $this->query( $sql, $fname );
-		if ( !$res ) {
-			return null;
-		}
-		if ( $this->fetchObject( $res ) ) {
-			return true;
-		}
-		return false;
-
-	}
-
-	/**
-	 * Returns the size of a text field, or -1 for "unlimited"
-	 * @param $table String: table name
-	 * @param $field String: column name
-	 * @return Integer: length or -1 for unlimited
-	 */
-	public function textFieldSize( $table, $field ) {
-		$table = $this->tableName( $table );
-		$sql = <<<SQL
-SELECT length as size
-FROM sysibm.syscolumns sc
-WHERE sc.name='$field' AND sc.tbname='$table'
-AND sc.tbcreator='$this->mSchema'
-SQL;
-		$res = $this->query( $sql );
-		$row = $this->fetchObject( $res );
-		$size = $row->size;
-		return $size;
-	}
-
-	/**
-	 * Description is left as an exercise for the reader
-	 * @param $b Mixed: data to be encoded
-	 * @return IBM_DB2Blob
-	 */
-	public function encodeBlob( $b ) {
-		return new IBM_DB2Blob( $b );
-	}
-
-	/**
-	 * Description is left as an exercise for the reader
-	 * @param $b IBM_DB2Blob: data to be decoded
-	 * @return mixed
-	 */
-	public function decodeBlob( $b ) {
-		return "$b";
-	}
-
-	/**
-	 * Convert into a list of string being concatenated
-	 * @param $stringList Array: strings that need to be joined together
-	 *                    by the SQL engine
-	 * @return String: joined by the concatenation operator
-	 */
-	public function buildConcat( $stringList ) {
-		// || is equivalent to CONCAT
-		// Sample query: VALUES 'foo' CONCAT 'bar' CONCAT 'baz'
-		return implode( ' || ', $stringList );
-	}
-
-	/**
-	 * Generates the SQL required to convert a DB2 timestamp into a Unix epoch
-	 * @param $column String: name of timestamp column
-	 * @return String: SQL code
-	 */
-	public function extractUnixEpoch( $column ) {
-		// TODO
-		// see SpecialAncientpages
-	}
-
-	######################################
-	# Prepared statements
-	######################################
-
-	/**
-	 * Intended to be compatible with the PEAR::DB wrapper functions.
-	 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
-	 *
-	 * ? = scalar value, quoted as necessary
-	 * ! = raw SQL bit (a function for instance)
-	 * & = filename; reads the file and inserts as a blob
-	 *     (we don't use this though...)
-	 * @param $sql String: SQL statement with appropriate markers
-	 * @param $func String: Name of the function, for profiling
-	 * @return resource a prepared DB2 SQL statement
-	 */
-	public function prepare( $sql, $func = 'DB2::prepare' ) {
-		$stmt = db2_prepare( $this->mConn, $sql, $this->mStmtOptions );
-		return $stmt;
-	}
-
-	/**
-	 * Frees resources associated with a prepared statement
-	 * @return Boolean success or failure
-	 */
-	public function freePrepared( $prepared ) {
-		return db2_free_stmt( $prepared );
-	}
-
-	/**
-	 * Execute a prepared query with the various arguments
-	 * @param $prepared String: the prepared sql
-	 * @param $args Mixed: either an array here, or put scalars as varargs
-	 * @return Resource: results object
-	 */
-	public function execute( $prepared, $args = null ) {
-		if( !is_array( $args ) ) {
-			# Pull the var args
-			$args = func_get_args();
-			array_shift( $args );
-		}
-		$res = db2_execute( $prepared, $args );
-		if ( !$res ) {
-			$this->installPrint( db2_stmt_errormsg() );
-		}
-		return $res;
-	}
-
-	/**
-	 * For faking prepared SQL statements on DBs that don't support
-	 * it directly.
-	 * @param $preparedQuery String: a 'preparable' SQL statement
-	 * @param $args Array of arguments to fill it with
-	 * @return String: executable statement
-	 */
-	public function fillPrepared( $preparedQuery, $args ) {
-		reset( $args );
-		$this->preparedArgs =& $args;
-
-		foreach ( $args as $i => $arg ) {
-			db2_bind_param( $preparedQuery, $i+1, $args[$i] );
-		}
-
-		return $preparedQuery;
-	}
-
-	/**
-	 * Switches module between regular and install modes
-	 * @return string
-	 */
-	public function setMode( $mode ) {
-		$old = $this->mMode;
-		$this->mMode = $mode;
-		return $old;
-	}
-
-	/**
-	 * Bitwise negation of a column or value in SQL
-	 * Same as (~field) in C
-	 * @param $field String
-	 * @return String
-	 */
-	function bitNot( $field ) {
-		// expecting bit-fields smaller than 4bytes
-		return "BITNOT( $field )";
-	}
-
-	/**
-	 * Bitwise AND of two columns or values in SQL
-	 * Same as (fieldLeft & fieldRight) in C
-	 * @param $fieldLeft String
-	 * @param $fieldRight String
-	 * @return String
-	 */
-	function bitAnd( $fieldLeft, $fieldRight ) {
-		return "BITAND( $fieldLeft, $fieldRight )";
-	}
-
-	/**
-	 * Bitwise OR of two columns or values in SQL
-	 * Same as (fieldLeft | fieldRight) in C
-	 * @param $fieldLeft String
-	 * @param $fieldRight String
-	 * @return String
-	 */
-	function bitOr( $fieldLeft, $fieldRight ) {
-		return "BITOR( $fieldLeft, $fieldRight )";
-	}
-}
-
-class IBM_DB2Helper {
-	public static function makeArray( $maybeArray ) {
-		if ( !is_array( $maybeArray ) ) {
-			return array( $maybeArray );
-		}
-
-		return $maybeArray;
-	}
-}
diff --git a/includes/db/DatabaseMssql.php b/includes/db/DatabaseMssql.php
index 914ab408..6c45ffaf 100644
--- a/includes/db/DatabaseMssql.php
+++ b/includes/db/DatabaseMssql.php
@@ -28,9 +28,9 @@
  * @ingroup Database
  */
 class DatabaseMssql extends DatabaseBase {
-	var $mInsertId = NULL;
-	var $mLastResult = NULL;
-	var $mAffectedRows = NULL;
+	var $mInsertId = null;
+	var $mLastResult = null;
+	var $mAffectedRows = null;
 
 	var $mPort;
 
@@ -61,6 +61,11 @@ class DatabaseMssql extends DatabaseBase {
 
 	/**
 	 * Usually aborts on failure
+	 * @param string $server
+	 * @param string $user
+	 * @param string $password
+	 * @param string $dbName
+	 * @throws DBConnectionError
 	 * @return bool|DatabaseBase|null
 	 */
 	function open( $server, $user, $password, $dbName ) {
@@ -97,7 +102,7 @@ class DatabaseMssql extends DatabaseBase {
 		$ntAuthPassTest = strtolower( $password );
 
 		// Decide which auth scenerio to use
-		if( $ntAuthPassTest == 'ntauth' && $ntAuthUserTest == 'ntauth' ){
+		if( $ntAuthPassTest == 'ntauth' && $ntAuthUserTest == 'ntauth' ) {
 			// Don't add credentials to $connectionInfo
 		} else {
 			$connectionInfo['UID'] = $user;
@@ -139,7 +144,7 @@ class DatabaseMssql extends DatabaseBase {
 		// $this->limitResult();
 		if ( preg_match( '/\bLIMIT\s*/i', $sql ) ) {
 			// massage LIMIT -> TopN
-			$sql = $this->LimitToTopN( $sql ) ;
+			$sql = $this->LimitToTopN( $sql );
 		}
 
 		// MSSQL doesn't have EXTRACT(epoch FROM XXX)
@@ -151,7 +156,7 @@ class DatabaseMssql extends DatabaseBase {
 		// perform query
 		$stmt = sqlsrv_query( $this->mConn, $sql );
 		if ( $stmt == false ) {
-			$message = "A database error has occurred.  Did you forget to run maintenance/update.php after upgrading?  See: http://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
+			$message = "A database error has occurred. Did you forget to run maintenance/update.php after upgrading?  See: http://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
 				"Query: " . htmlentities( $sql ) . "\n" .
 				"Function: " . __METHOD__ . "\n";
 			// process each error (our driver will give us an array of errors unlike other providers)
@@ -279,7 +284,7 @@ class DatabaseMssql extends DatabaseBase {
 	 * @param $vars    Mixed: array or string, field name(s) to be retrieved
 	 * @param $conds   Mixed: array or string, condition(s) for WHERE
 	 * @param $fname   String: calling function name (use __METHOD__) for logs/profiling
-	 * @param $options Array: associative array of options (e.g. array('GROUP BY' => 'page_title')),
+	 * @param array $options associative array of options (e.g. array('GROUP BY' => 'page_title')),
 	 *                 see Database::makeSelectOptions code for list of supported stuff
 	 * @param $join_conds Array: Associative array of table join conditions (optional)
 	 *						   (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
@@ -304,7 +309,7 @@ class DatabaseMssql extends DatabaseBase {
 	 * @param $vars    Mixed:  Array or string, field name(s) to be retrieved
 	 * @param $conds   Mixed:  Array or string, condition(s) for WHERE
 	 * @param $fname   String: Calling function name (use __METHOD__) for logs/profiling
-	 * @param $options Array:  Associative array of options (e.g. array('GROUP BY' => 'page_title')),
+	 * @param array $options  Associative array of options (e.g. array('GROUP BY' => 'page_title')),
 	 *                 see Database::makeSelectOptions code for list of supported stuff
 	 * @param $join_conds Array: Associative array of table join conditions (optional)
 	 *                    (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
@@ -314,7 +319,7 @@ class DatabaseMssql extends DatabaseBase {
 		if ( isset( $options['EXPLAIN'] ) ) {
 			unset( $options['EXPLAIN'] );
 		}
-		return parent::selectSQLText(  $table, $vars, $conds, $fname, $options, $join_conds );
+		return parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 	}
 
 	/**
@@ -348,7 +353,7 @@ class DatabaseMssql extends DatabaseBase {
 		$sql = "sp_helpindex '" . $table . "'";
 		$res = $this->query( $sql, $fname );
 		if ( !$res ) {
-			return NULL;
+			return null;
 		}
 
 		$result = array();
@@ -380,6 +385,11 @@ class DatabaseMssql extends DatabaseBase {
 	 *
 	 * Usually aborts on failure
 	 * If errors are explicitly ignored, returns success
+	 * @param string $table
+	 * @param array $arrToInsert
+	 * @param string $fname
+	 * @param array $options
+	 * @throws DBQueryError
 	 * @return bool
 	 */
 	function insert( $table, $arrToInsert, $fname = 'DatabaseMssql::insert', $options = array() ) {
@@ -404,7 +414,7 @@ class DatabaseMssql extends DatabaseBase {
 		$identity = null;
 		$tableRaw = preg_replace( '#\[([^\]]*)\]#', '$1', $table ); // strip matching square brackets from table name
 		$res = $this->doQuery( "SELECT NAME AS idColumn FROM SYS.IDENTITY_COLUMNS WHERE OBJECT_NAME(OBJECT_ID)='{$tableRaw}'" );
-		if( $res && $res->numrows() ){
+		if( $res && $res->numrows() ) {
 			// There is an identity for this table.
 			$identity = array_pop( $res->fetch( SQLSRV_FETCH_ASSOC ) );
 		}
@@ -421,9 +431,9 @@ class DatabaseMssql extends DatabaseBase {
 				// iterate through
 				foreach ($a as $k => $v ) {
 					if ( $k == $identity ) {
-						if( !is_null($v) ){
+						if( !is_null($v) ) {
 							// there is a value being passed to us, we need to turn on and off inserted identity
-							$sqlPre = "SET IDENTITY_INSERT $table ON;" ;
+							$sqlPre = "SET IDENTITY_INSERT $table ON;";
 							$sqlPost = ";SET IDENTITY_INSERT $table OFF;";
 
 						} else {
@@ -474,7 +484,7 @@ class DatabaseMssql extends DatabaseBase {
 				} elseif ( is_array( $value ) || is_object( $value ) ) {
 					if ( is_object( $value ) && strtolower( get_class( $value ) ) == 'blob' ) {
 						$sql .= $this->addQuotes( $value );
-					}  else {
+					} else {
 						$sql .= $this->addQuotes( serialize( $value ) );
 					}
 				} else {
@@ -488,7 +498,7 @@ class DatabaseMssql extends DatabaseBase {
 
 			if ( $ret === false ) {
 				throw new DBQueryError( $this, $this->getErrors(), $this->lastErrno(), $sql, $fname );
-			} elseif ( $ret != NULL ) {
+			} elseif ( $ret != null ) {
 				// remember number of rows affected
 				$this->mAffectedRows = sqlsrv_rows_affected( $ret );
 				if ( !is_null($identity) ) {
@@ -510,7 +520,15 @@ class DatabaseMssql extends DatabaseBase {
 	 * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
 	 * $conds may be "*" to copy the whole table
 	 * srcTable may be an array of tables.
-	 * @return null|\ResultWrapper
+	 * @param string $destTable
+	 * @param array|string $srcTable
+	 * @param array $varMap
+	 * @param array $conds
+	 * @param string $fname
+	 * @param array $insertOptions
+	 * @param array $selectOptions
+	 * @throws DBQueryError
+	 * @return null|ResultWrapper
 	 */
 	function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabaseMssql::insertSelect',
 		$insertOptions = array(), $selectOptions = array() ) {
@@ -518,12 +536,12 @@ class DatabaseMssql extends DatabaseBase {
 
 		if ( $ret === false ) {
 			throw new DBQueryError( $this, $this->getErrors(), $this->lastErrno(), /*$sql*/ '', $fname );
-		} elseif ( $ret != NULL ) {
+		} elseif ( $ret != null ) {
 			// remember number of rows affected
 			$this->mAffectedRows = sqlsrv_rows_affected( $ret );
 			return $ret;
 		}
-		return NULL;
+		return null;
 	}
 
 	/**
@@ -590,9 +608,9 @@ class DatabaseMssql extends DatabaseBase {
 		} else {
 			$sql = '
 				SELECT * FROM (
-				  SELECT sub2.*, ROW_NUMBER() OVER(ORDER BY sub2.line2) AS line3 FROM (
-					SELECT 1 AS line2, sub1.* FROM (' . $sql . ') AS sub1
-				  ) as sub2
+					SELECT sub2.*, ROW_NUMBER() OVER(ORDER BY sub2.line2) AS line3 FROM (
+						SELECT 1 AS line2, sub1.* FROM (' . $sql . ') AS sub1
+					) as sub2
 				) AS sub3
 				WHERE line3 BETWEEN ' . ( $offset + 1 ) . ' AND ' . ( $offset + $limit );
 			return $sql;
@@ -720,6 +738,8 @@ class DatabaseMssql extends DatabaseBase {
 	 * Escapes a identifier for use inm SQL.
 	 * Throws an exception if it is invalid.
 	 * Reference: http://msdn.microsoft.com/en-us/library/aa224033%28v=SQL.80%29.aspx
+	 * @param $identifier
+	 * @throws MWException
 	 * @return string
 	 */
 	private function escapeIdentifier( $identifier ) {
@@ -750,17 +770,17 @@ class DatabaseMssql extends DatabaseBase {
 		$newUser = $this->escapeIdentifier( $newUser );
 		$loginPassword = $this->addQuotes( $loginPassword );
 
-		$this->doQuery("CREATE DATABASE $dbName;");
-		$this->doQuery("USE $dbName;");
-		$this->doQuery("CREATE SCHEMA $dbName;");
-		$this->doQuery("
+		$this->doQuery( "CREATE DATABASE $dbName;" );
+		$this->doQuery( "USE $dbName;" );
+		$this->doQuery( "CREATE SCHEMA $dbName;" );
+		$this->doQuery( "
 						CREATE
 							LOGIN $newUser
 						WITH
 							PASSWORD=$loginPassword
 						;
-					");
-		$this->doQuery("
+					" );
+		$this->doQuery( "
 						CREATE
 							USER $newUser
 						FOR
@@ -768,8 +788,8 @@ class DatabaseMssql extends DatabaseBase {
 						WITH
 							DEFAULT_SCHEMA=$dbName
 						;
-					");
-		$this->doQuery("
+					" );
+		$this->doQuery( "
 						GRANT
 							BACKUP DATABASE,
 							BACKUP LOG,
@@ -784,17 +804,15 @@ class DatabaseMssql extends DatabaseBase {
 							DATABASE::$dbName
 						TO $newUser
 						;
-					");
-		$this->doQuery("
+					" );
+		$this->doQuery( "
 						GRANT
 							CONTROL
 						ON
 							SCHEMA::$dbName
 						TO $newUser
 						;
-					");
-
-
+					" );
 	}
 
 	function encodeBlob( $b ) {
@@ -873,7 +891,7 @@ class DatabaseMssql extends DatabaseBase {
 	/**
 	 * @private
 	 *
-	 * @param $options Array: an associative array of options to be turned into
+	 * @param array $options an associative array of options to be turned into
 	 *                 an SQL query, valid keys are listed in the function.
 	 * @return Array
 	 */
@@ -888,29 +906,23 @@ class DatabaseMssql extends DatabaseBase {
 			}
 		}
 
-		if ( isset( $options['GROUP BY'] ) ) {
-			$tailOpts .= " GROUP BY {$options['GROUP BY']}";
-		}
-		if ( isset( $options['HAVING'] ) ) {
-			$tailOpts .= " HAVING {$options['GROUP BY']}";
-		}
-		if ( isset( $options['ORDER BY'] ) ) {
-			$tailOpts .= " ORDER BY {$options['ORDER BY']}";
-		}
+		$tailOpts .= $this->makeGroupByWithHaving( $options );
+
+		$tailOpts .= $this->makeOrderBy( $options );
 
 		if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) {
 			$startOpts .= 'DISTINCT';
 		}
 
 		// we want this to be compatible with the output of parent::makeSelectOptions()
-		return array( $startOpts, '' , $tailOpts, '' );
+		return array( $startOpts, '', $tailOpts, '' );
 	}
 
 	/**
 	 * Get the type of the DBMS, as it appears in $wgDBtype.
 	 * @return string
 	 */
-	function getType(){
+	function getType() {
 		return 'mssql';
 	}
 
@@ -1118,6 +1130,5 @@ class MssqlResult {
 
 	public function free() {
 		unset( $this->mRows );
-		return;
 	}
 }
diff --git a/includes/db/DatabaseMysql.php b/includes/db/DatabaseMysql.php
index 7f389da9..27aae188 100644
--- a/includes/db/DatabaseMysql.php
+++ b/includes/db/DatabaseMysql.php
@@ -133,7 +133,7 @@ class DatabaseMysql extends DatabaseBase {
 				substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 
 			wfProfileOut( __METHOD__ );
-			$this->reportConnectionError( $error );
+			return $this->reportConnectionError( $error );
 		}
 
 		if ( $dbName != '' ) {
@@ -146,7 +146,7 @@ class DatabaseMysql extends DatabaseBase {
 					"from client host " . wfHostname() . "\n" );
 
 				wfProfileOut( __METHOD__ );
-				$this->reportConnectionError( "Error selecting database $dbName" );
+				return $this->reportConnectionError( "Error selecting database $dbName" );
 			}
 		}
 
@@ -193,7 +193,7 @@ class DatabaseMysql extends DatabaseBase {
 
 	/**
 	 * @param $res ResultWrapper
-	 * @return object|stdClass
+	 * @return object|bool
 	 * @throws DBUnexpectedError
 	 */
 	function fetchObject( $res ) {
@@ -208,7 +208,7 @@ class DatabaseMysql extends DatabaseBase {
 		// Unfortunately, mysql_fetch_object does not reset the last errno.
 		// Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 		// these are the only errors mysql_fetch_object can cause.
-		// See http://dev.mysql.com/doc/refman/5.0/es/mysql-fetch-row.html.
+		// See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 		if( $errno == 2000 || $errno == 2013 ) {
 			throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 		}
@@ -217,7 +217,7 @@ class DatabaseMysql extends DatabaseBase {
 
 	/**
 	 * @param $res ResultWrapper
-	 * @return array
+	 * @return array|bool
 	 * @throws DBUnexpectedError
 	 */
 	function fetchRow( $res ) {
@@ -232,7 +232,7 @@ class DatabaseMysql extends DatabaseBase {
 		// Unfortunately, mysql_fetch_array does not reset the last errno.
 		// Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 		// these are the only errors mysql_fetch_object can cause.
-		// See http://dev.mysql.com/doc/refman/5.0/es/mysql-fetch-row.html.
+		// See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 		if( $errno == 2000 || $errno == 2013 ) {
 			throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 		}
@@ -251,9 +251,11 @@ class DatabaseMysql extends DatabaseBase {
 		wfSuppressWarnings();
 		$n = mysql_num_rows( $res );
 		wfRestoreWarnings();
-		if( $this->lastErrno() ) {
-			throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
-		}
+		// Unfortunately, mysql_num_rows does not reset the last errno.
+		// We are not checking for any errors here, since
+		// these are no errors mysql_num_rows can cause.
+		// See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
+		// See https://bugzilla.wikimedia.org/42430
 		return $n;
 	}
 
@@ -361,7 +363,7 @@ class DatabaseMysql extends DatabaseBase {
 	 * @param $options string|array
 	 * @return int
 	 */
-	public function estimateRowCount( $table, $vars='*', $conds='', $fname = 'DatabaseMysql::estimateRowCount', $options = array() ) {
+	public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabaseMysql::estimateRowCount', $options = array() ) {
 		$options['EXPLAIN'] = true;
 		$res = $this->select( $table, $vars, $conds, $fname, $options );
 		if ( $res === false ) {
@@ -393,7 +395,7 @@ class DatabaseMysql extends DatabaseBase {
 		for( $i = 0; $i < $n; $i++ ) {
 			$meta = mysql_fetch_field( $res->result, $i );
 			if( $field == $meta->name ) {
-				return new MySQLField($meta);
+				return new MySQLField( $meta );
 			}
 		}
 		return false;
@@ -414,6 +416,7 @@ class DatabaseMysql extends DatabaseBase {
 		# http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 		$table = $this->tableName( $table );
 		$index = $this->indexName( $index );
+
 		$sql = 'SHOW INDEX FROM ' . $table;
 		$res = $this->query( $sql, $fname );
 
@@ -428,7 +431,6 @@ class DatabaseMysql extends DatabaseBase {
 				$result[] = $row;
 			}
 		}
-
 		return empty( $result ) ? false : $result;
 	}
 
@@ -449,7 +451,7 @@ class DatabaseMysql extends DatabaseBase {
 	function strencode( $s ) {
 		$sQuoted = mysql_real_escape_string( $s, $this->mConn );
 
-		if($sQuoted === false) {
+		if( $sQuoted === false ) {
 			$this->ping();
 			$sQuoted = mysql_real_escape_string( $s, $this->mConn );
 		}
@@ -597,10 +599,9 @@ class DatabaseMysql extends DatabaseBase {
 		if ( $res && $row = $this->fetchRow( $res ) ) {
 			wfProfileOut( $fname );
 			return $row[0];
-		} else {
-			wfProfileOut( $fname );
-			return false;
 		}
+		wfProfileOut( $fname );
+		return false;
 	}
 
 	/**
@@ -686,7 +687,7 @@ class DatabaseMysql extends DatabaseBase {
 
 	public function streamStatementEnd( &$sql, &$newLine ) {
 		if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
-			preg_match( '/^DELIMITER\s+(\S+)/' , $newLine, $m );
+			preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 			$this->delimiter = $m[1];
 			$newLine = '';
 		}
@@ -696,8 +697,8 @@ class DatabaseMysql extends DatabaseBase {
 	/**
 	 * Check to see if a named lock is available. This is non-blocking.
 	 *
-	 * @param $lockName String: name of lock to poll
-	 * @param $method String: name of method calling us
+	 * @param string $lockName name of lock to poll
+	 * @param string $method name of method calling us
 	 * @return Boolean
 	 * @since 1.20
 	 */
@@ -722,7 +723,7 @@ class DatabaseMysql extends DatabaseBase {
 		if( $row->lockstatus == 1 ) {
 			return true;
 		} else {
-			wfDebug( __METHOD__." failed to acquire lock\n" );
+			wfDebug( __METHOD__ . " failed to acquire lock\n" );
 			return false;
 		}
 	}
@@ -745,6 +746,7 @@ class DatabaseMysql extends DatabaseBase {
 	 * @param $write array
 	 * @param $method string
 	 * @param $lowPriority bool
+	 * @return bool
 	 */
 	public function lockTables( $read, $write, $method, $lowPriority = true ) {
 		$items = array();
@@ -760,13 +762,16 @@ class DatabaseMysql extends DatabaseBase {
 		}
 		$sql = "LOCK TABLES " . implode( ',', $items );
 		$this->query( $sql, $method );
+		return true;
 	}
 
 	/**
 	 * @param $method string
+	 * @return bool
 	 */
 	public function unlockTables( $method ) {
 		$this->query( "UNLOCK TABLES", $method );
+		return true;
 	}
 
 	/**
@@ -805,7 +810,8 @@ class DatabaseMysql extends DatabaseBase {
 	 * @param $delVar string
 	 * @param $joinVar string
 	 * @param $conds array|string
-	 * @param $fname bool
+	 * @param bool|string $fname bool
+	 * @throws DBUnexpectedError
 	 * @return bool|ResultWrapper
 	 */
 	function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabaseBase::deleteJoin' ) {
@@ -889,8 +895,8 @@ class DatabaseMysql extends DatabaseBase {
 	/**
 	 * List all tables on the database
 	 *
-	 * @param $prefix string Only show tables with this prefix, e.g. mw_
-	 * @param $fname String: calling function name
+	 * @param string $prefix Only show tables with this prefix, e.g. mw_
+	 * @param string $fname calling function name
 	 * @return array
 	 */
 	function listTables( $prefix = null, $fname = 'DatabaseMysql::listTables' ) {
@@ -899,7 +905,7 @@ class DatabaseMysql extends DatabaseBase {
 		$endArray = array();
 
 		foreach( $result as $table ) {
-			$vars = get_object_vars($table);
+			$vars = get_object_vars( $table );
 			$table = array_pop( $vars );
 
 			if( !$prefix || strpos( $table, $prefix ) === 0 ) {
@@ -952,13 +958,6 @@ class DatabaseMysql extends DatabaseBase {
 }
 
 /**
- * Legacy support: Database == DatabaseMysql
- *
- * @deprecated in 1.16
- */
-class Database extends DatabaseMysql {}
-
-/**
  * Utility class.
  * @ingroup Database
  */
diff --git a/includes/db/DatabaseOracle.php b/includes/db/DatabaseOracle.php
index 7d8884fb..75b3550a 100644
--- a/includes/db/DatabaseOracle.php
+++ b/includes/db/DatabaseOracle.php
@@ -23,7 +23,7 @@
 
 /**
  * The oci8 extension is fairly weak and doesn't support oci_num_rows, among
- * other things.  We use a wrapper class to handle that and other
+ * other things. We use a wrapper class to handle that and other
  * Oracle-specific bits, like converting column names back to lowercase.
  * @ingroup Database
  */
@@ -69,7 +69,7 @@ class ORAResult {
 			$this->nrows = count( $this->rows );
 		}
 
-		if ($this->nrows > 0) {
+		if ( $this->nrows > 0 ) {
 			foreach ( $this->rows[0] as $k => $v ) {
 				$this->columns[$k] = strtolower( oci_field_name( $stmt, $k + 1 ) );
 			}
@@ -80,7 +80,7 @@ class ORAResult {
 	}
 
 	public function free() {
-		unset($this->db);
+		unset( $this->db );
 	}
 
 	public function seek( $row ) {
@@ -92,7 +92,7 @@ class ORAResult {
 	}
 
 	public function numFields() {
-		return count($this->columns);
+		return count( $this->columns );
 	}
 
 	public function fetchObject() {
@@ -241,6 +241,11 @@ class DatabaseOracle extends DatabaseBase {
 
 	/**
 	 * Usually aborts on failure
+	 * @param string $server
+	 * @param string $user
+	 * @param string $password
+	 * @param string $dbName
+	 * @throws DBConnectionError
 	 * @return DatabaseBase|null
 	 */
 	function open( $server, $user, $password, $dbName ) {
@@ -313,7 +318,7 @@ class DatabaseOracle extends DatabaseBase {
 
 	protected function doQuery( $sql ) {
 		wfDebug( "SQL: [$sql]\n" );
-		if ( !mb_check_encoding( $sql ) ) {
+		if ( !StringUtils::isUtf8( $sql ) ) {
 			throw new MWException( "SQL encoding is invalid\n$sql" );
 		}
 
@@ -628,7 +633,7 @@ class DatabaseOracle extends DatabaseBase {
 		}
 		list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 		if ( is_array( $srcTable ) ) {
-			$srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
+			$srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 		} else {
 			$srcTable = $this->tableName( $srcTable );
 		}
@@ -751,7 +756,7 @@ class DatabaseOracle extends DatabaseBase {
 
 	function unionQueries( $sqls, $all ) {
 		$glue = ' UNION ALL ';
-		return 'SELECT * ' . ( $all ? '':'/* UNION_UNIQUE */ ' ) . 'FROM (' . implode( $glue, $sqls ) . ')' ;
+		return 'SELECT * ' . ( $all ? '':'/* UNION_UNIQUE */ ' ) . 'FROM (' . implode( $glue, $sqls ) . ')';
 	}
 
 	function wasDeadlock() {
@@ -773,8 +778,8 @@ class DatabaseOracle extends DatabaseBase {
 
 	function listTables( $prefix = null, $fname = 'DatabaseOracle::listTables' ) {
 		$listWhere = '';
-		if (!empty($prefix)) {
-			$listWhere = ' AND table_name LIKE \''.strtoupper($prefix).'%\'';
+		if ( !empty( $prefix ) ) {
+			$listWhere = ' AND table_name LIKE \'' . strtoupper( $prefix ) . '%\'';
 		}
 
 		$owner = strtoupper( $this->mDBname );
@@ -782,12 +787,12 @@ class DatabaseOracle extends DatabaseBase {
 
 		// dirty code ... i know
 		$endArray = array();
-		$endArray[] = strtoupper($prefix.'MWUSER');
-		$endArray[] = strtoupper($prefix.'PAGE');
-		$endArray[] = strtoupper($prefix.'IMAGE');
+		$endArray[] = strtoupper( $prefix . 'MWUSER' );
+		$endArray[] = strtoupper( $prefix . 'PAGE' );
+		$endArray[] = strtoupper( $prefix . 'IMAGE' );
 		$fixedOrderTabs = $endArray;
-		while (($row = $result->fetchRow()) !== false) {
-			if (!in_array($row['table_name'], $fixedOrderTabs))
+		while ( ($row = $result->fetchRow()) !== false ) {
+			if ( !in_array( $row['table_name'], $fixedOrderTabs ) )
 				$endArray[] = $row['table_name'];
 		}
 
@@ -795,7 +800,7 @@ class DatabaseOracle extends DatabaseBase {
 	}
 
 	public function dropTable( $tableName, $fName = 'DatabaseOracle::dropTable' ) {
-		$tableName = $this->tableName($tableName);
+		$tableName = $this->tableName( $tableName );
 		if( !$this->tableExists( $tableName ) ) {
 			return false;
 		}
@@ -841,7 +846,7 @@ class DatabaseOracle extends DatabaseBase {
 	function getServerVersion() {
 		//better version number, fallback on driver
 		$rset = $this->doQuery( 'SELECT version FROM product_component_version WHERE UPPER(product) LIKE \'ORACLE DATABASE%\'' );
-		if ( !( $row =  $rset->fetchRow() ) ) {
+		if ( !( $row = $rset->fetchRow() ) ) {
 			return oci_server_version( $this->mConn );
 		}
 		return $row['version'];
@@ -902,7 +907,7 @@ class DatabaseOracle extends DatabaseBase {
 			$table = array_map( array( &$this, 'tableNameInternal' ), $table );
 			$tableWhere = 'IN (';
 			foreach( $table as &$singleTable ) {
-				$singleTable = $this->removeIdentifierQuotes($singleTable);
+				$singleTable = $this->removeIdentifierQuotes( $singleTable );
 				if ( isset( $this->mFieldInfoCache["$singleTable.$field"] ) ) {
 					return $this->mFieldInfoCache["$singleTable.$field"];
 				}
@@ -910,14 +915,14 @@ class DatabaseOracle extends DatabaseBase {
 			}
 			$tableWhere = rtrim( $tableWhere, ',' ) . ')';
 		} else {
-			$table = $this->removeIdentifierQuotes(  $this->tableNameInternal( $table ) );
+			$table = $this->removeIdentifierQuotes( $this->tableNameInternal( $table ) );
 			if ( isset( $this->mFieldInfoCache["$table.$field"] ) ) {
 				return $this->mFieldInfoCache["$table.$field"];
 			}
 			$tableWhere = '= \''.$table.'\'';
 		}
 
-		$fieldInfoStmt = oci_parse( $this->mConn, 'SELECT * FROM wiki_field_info_full WHERE table_name '.$tableWhere.' and column_name = \''.$field.'\'' );
+		$fieldInfoStmt = oci_parse( $this->mConn, 'SELECT * FROM wiki_field_info_full WHERE table_name ' . $tableWhere . ' and column_name = \'' . $field . '\'' );
 		if ( oci_execute( $fieldInfoStmt, $this->execFlags() ) === false ) {
 			$e = oci_error( $fieldInfoStmt );
 			$this->reportQueryError( $e['message'], $e['code'], 'fieldInfo QUERY', __METHOD__ );
@@ -952,7 +957,7 @@ class DatabaseOracle extends DatabaseBase {
 		if ( is_array( $table ) ) {
 			throw new DBUnexpectedError( $this, 'DatabaseOracle::fieldInfo called with table array!' );
 		}
-		return $this->fieldInfoMulti ($table, $field);
+		return $this->fieldInfoMulti( $table, $field );
 	}
 
 	protected function doBegin( $fname = 'DatabaseOracle::begin' ) {
@@ -1061,7 +1066,7 @@ class DatabaseOracle extends DatabaseBase {
 		if ( $db == null || $db == $this->mUser ) {
 			return true;
 		}
-		$sql = 'ALTER SESSION SET CURRENT_SCHEMA=' . strtoupper($db);
+		$sql = 'ALTER SESSION SET CURRENT_SCHEMA=' . strtoupper( $db );
 		$stmt = oci_parse( $this->mConn, $sql );
 		wfSuppressWarnings();
 		$success = oci_execute( $stmt );
@@ -1096,11 +1101,11 @@ class DatabaseOracle extends DatabaseBase {
 	}
 
 	public function removeIdentifierQuotes( $s ) {
-		return strpos($s, '/*Q*/') === FALSE ? $s : substr($s, 5);
+		return strpos( $s, '/*Q*/' ) === false ? $s : substr( $s, 5 );
 	}
 
 	public function isQuotedIdentifier( $s ) {
-		return strpos($s, '/*Q*/') !== FALSE;
+		return strpos( $s, '/*Q*/' ) !== false;
 	}
 
 	private function wrapFieldForWhere( $table, &$col, &$val ) {
@@ -1111,7 +1116,7 @@ class DatabaseOracle extends DatabaseBase {
 		if ( $col_type == 'CLOB' ) {
 			$col = 'TO_CHAR(' . $col . ')';
 			$val = $wgContLang->checkTitleEncoding( $val );
-		} elseif ( $col_type == 'VARCHAR2' && !mb_check_encoding( $val ) ) {
+		} elseif ( $col_type == 'VARCHAR2' ) {
 			$val = $wgContLang->checkTitleEncoding( $val );
 		}
 	}
@@ -1134,7 +1139,7 @@ class DatabaseOracle extends DatabaseBase {
 	}
 
 	function selectRow( $table, $vars, $conds, $fname = 'DatabaseOracle::selectRow', $options = array(), $join_conds = array() ) {
-		if ( is_array($conds) ) {
+		if ( is_array( $conds ) ) {
 			$conds = $this->wrapConditionsForWhere( $table, $conds );
 		}
 		return parent::selectRow( $table, $vars, $conds, $fname, $options, $join_conds );
@@ -1146,7 +1151,7 @@ class DatabaseOracle extends DatabaseBase {
 	 *
 	 * @private
 	 *
-	 * @param $options Array: an associative array of options to be turned into
+	 * @param array $options an associative array of options to be turned into
 	 *              an SQL query, valid keys are listed in the function.
 	 * @return array
 	 */
@@ -1161,15 +1166,14 @@ class DatabaseOracle extends DatabaseBase {
 			}
 		}
 
-		if ( isset( $options['GROUP BY'] ) ) {
-			$preLimitTail .= " GROUP BY {$options['GROUP BY']}";
-		}
-		if ( isset( $options['ORDER BY'] ) ) {
-			$preLimitTail .= " ORDER BY {$options['ORDER BY']}";
+		$preLimitTail .= $this->makeGroupByWithHaving( $options );
+
+		$preLimitTail .= $this->makeOrderBy( $options );
+
+		if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
+			$postLimitTail .= ' FOR UPDATE';
 		}
 
-		# if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $tailOpts .= ' FOR UPDATE';
-		# if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $tailOpts .= ' LOCK IN SHARE MODE';
 		if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
 			$startOpts .= 'DISTINCT';
 		}
@@ -1184,13 +1188,13 @@ class DatabaseOracle extends DatabaseBase {
 	}
 
 	public function delete( $table, $conds, $fname = 'DatabaseOracle::delete' ) {
-		if ( is_array($conds) ) {
+		if ( is_array( $conds ) ) {
 			$conds = $this->wrapConditionsForWhere( $table, $conds );
 		}
 		// a hack for deleting pages, users and images (which have non-nullable FKs)
 		// all deletions on these tables have transactions so final failure rollbacks these updates
 		$table = $this->tableName( $table );
-		if ( $table == $this->tableName( 'user' )  ) {
+		if ( $table == $this->tableName( 'user' ) ) {
 				$this->update( 'archive', array( 'ar_user' => 0 ), array( 'ar_user' => $conds['user_id'] ), $fname );
 				$this->update( 'ipblocks', array( 'ipb_user' => 0 ), array( 'ipb_user' => $conds['user_id'] ), $fname );
 				$this->update( 'image', array( 'img_user' => 0 ), array( 'img_user' => $conds['user_id'] ), $fname );
@@ -1200,7 +1204,7 @@ class DatabaseOracle extends DatabaseBase {
 				$this->update( 'uploadstash', array( 'us_user' => 0 ), array( 'us_user' => $conds['user_id'] ), $fname );
 				$this->update( 'recentchanges', array( 'rc_user' => 0 ), array( 'rc_user' => $conds['user_id'] ), $fname );
 				$this->update( 'logging', array( 'log_user' => 0 ), array( 'log_user' => $conds['user_id'] ), $fname );
-		} elseif ( $table == $this->tableName( 'image' )  ) {
+		} elseif ( $table == $this->tableName( 'image' ) ) {
 				$this->update( 'oldimage', array( 'oi_name' => 0 ), array( 'oi_name' => $conds['img_name'] ), $fname );
 		}
 		return parent::delete( $table, $conds, $fname );
diff --git a/includes/db/DatabasePostgres.php b/includes/db/DatabasePostgres.php
index 457bf384..f32d7758 100644
--- a/includes/db/DatabasePostgres.php
+++ b/includes/db/DatabasePostgres.php
@@ -176,8 +176,8 @@ class PostgresTransactionState {
 				$old = reset( $this->mCurrentState );
 				$new = reset( $this->mNewState );
 				foreach ( self::$WATCHED as $watched ) {
-					if ($old !== $new) {
-						$this->log_changed($old, $new, $watched);
+					if ( $old !== $new ) {
+						$this->log_changed( $old, $new, $watched );
 					}
 					$old = next( $this->mCurrentState );
 					$new = next( $this->mNewState );
@@ -197,11 +197,11 @@ class PostgresTransactionState {
 	}
 
 	protected function log_changed( $old, $new, $watched ) {
-		wfDebug(sprintf($watched["desc"],
+		wfDebug( sprintf( $watched["desc"],
 			$this->mConn,
 			$this->describe_changed( $old, $watched["states"] ),
-			$this->describe_changed( $new, $watched["states"] ))
-		);
+			$this->describe_changed( $new, $watched["states"] )
+		) );
 	}
 }
 
@@ -218,7 +218,7 @@ class SavepointPostgres {
 	protected $id;
 	protected $didbegin;
 
-	public function __construct ($dbw, $id) {
+	public function __construct ( $dbw, $id ) {
 		$this->dbw = $dbw;
 		$this->id = $id;
 		$this->didbegin = false;
@@ -232,12 +232,14 @@ class SavepointPostgres {
 	public function __destruct() {
 		if ( $this->didbegin ) {
 			$this->dbw->rollback();
+			$this->didbegin = false;
 		}
 	}
 
 	public function commit() {
 		if ( $this->didbegin ) {
 			$this->dbw->commit();
+			$this->didbegin = false;
 		}
 	}
 
@@ -245,29 +247,29 @@ class SavepointPostgres {
 		global $wgDebugDBTransactions;
 		if ( $this->dbw->doQuery( $keyword . " " . $this->id ) !== false ) {
 			if ( $wgDebugDBTransactions ) {
-				wfDebug( sprintf ($msg_ok, $this->id ) );
+				wfDebug( sprintf ( $msg_ok, $this->id ) );
 			}
 		} else {
-			wfDebug( sprintf ($msg_failed, $this->id ) );
+			wfDebug( sprintf ( $msg_failed, $this->id ) );
 		}
 	}
 
 	public function savepoint() {
-		$this->query("SAVEPOINT",
+		$this->query( "SAVEPOINT",
 			"Transaction state: savepoint \"%s\" established.\n",
 			"Transaction state: establishment of savepoint \"%s\" FAILED.\n"
 		);
 	}
 
 	public function release() {
-		$this->query("RELEASE",
+		$this->query( "RELEASE",
 			"Transaction state: savepoint \"%s\" released.\n",
 			"Transaction state: release of savepoint \"%s\" FAILED.\n"
 		);
 	}
 
 	public function rollback() {
-		$this->query("ROLLBACK TO",
+		$this->query( "ROLLBACK TO",
 			"Transaction state: savepoint \"%s\" rolled back.\n",
 			"Transaction state: rollback of savepoint \"%s\" FAILED.\n"
 		);
@@ -325,6 +327,11 @@ class DatabasePostgres extends DatabaseBase {
 
 	/**
 	 * Usually aborts on failure
+	 * @param string $server
+	 * @param string $user
+	 * @param string $password
+	 * @param string $dbName
+	 * @throws DBConnectionError
 	 * @return DatabaseBase|null
 	 */
 	function open( $server, $user, $password, $dbName ) {
@@ -386,6 +393,9 @@ class DatabasePostgres extends DatabaseBase {
 		$this->query( "SET datestyle = 'ISO, YMD'", __METHOD__ );
 		$this->query( "SET timezone = 'GMT'", __METHOD__ );
 		$this->query( "SET standard_conforming_strings = on", __METHOD__ );
+		if ( $this->getServerVersion() >= 9.0 ) {
+			$this->query( "SET bytea_output = 'escape'", __METHOD__ ); // PHP bug 53127
+		}
 
 		global $wgDBmwschema;
 		$this->determineCoreSchema( $wgDBmwschema );
@@ -472,7 +482,6 @@ class DatabasePostgres extends DatabaseBase {
 		parent::reportQueryError( $error, $errno, $sql, $fname, false );
 	}
 
-
 	function queryIgnore( $sql, $fname = 'DatabasePostgres::queryIgnore' ) {
 		return $this->query( $sql, $fname, true );
 	}
@@ -599,7 +608,7 @@ class DatabasePostgres extends DatabaseBase {
 	 * Takes same arguments as Database::select()
 	 * @return int
 	 */
-	function estimateRowCount( $table, $vars = '*', $conds='', $fname = 'DatabasePostgres::estimateRowCount', $options = array() ) {
+	function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabasePostgres::estimateRowCount', $options = array() ) {
 		$options['EXPLAIN'] = true;
 		$res = $this->select( $table, $vars, $conds, $fname, $options );
 		$rows = -1;
@@ -677,7 +686,7 @@ class DatabasePostgres extends DatabaseBase {
 					AND	i.indclass[s.g] = opcls.oid
 					AND	pg_am.oid = opcls.opcmethod
 __INDEXATTR__;
-		$res = $this->query($sql, __METHOD__);
+		$res = $this->query( $sql, __METHOD__ );
 		$a = array();
 		if ( $res ) {
 			foreach ( $res as $row ) {
@@ -685,7 +694,7 @@ __INDEXATTR__;
 					$row->attname,
 					$row->opcname,
 					$row->amname,
-					$row->option);
+					$row->option );
 			}
 		} else {
 			return null;
@@ -693,7 +702,6 @@ __INDEXATTR__;
 		return $a;
 	}
 
-
 	function indexUnique( $table, $index, $fname = 'DatabasePostgres::indexUnique' ) {
 		$sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 			" AND indexdef LIKE 'CREATE UNIQUE%(" .
@@ -718,7 +726,7 @@ __INDEXATTR__;
 	 * @param $table   String: Name of the table to insert to.
 	 * @param $args    Array: Items to insert into the table.
 	 * @param $fname   String: Name of the function, for profiling
-	 * @param $options String or Array. Valid options: IGNORE
+	 * @param string $options or Array. Valid options: IGNORE
 	 *
 	 * @return bool Success of insert operation. IGNORE always returns true.
 	 */
@@ -728,7 +736,7 @@ __INDEXATTR__;
 		}
 
 		$table = $this->tableName( $table );
-		if (! isset( $this->numeric_version ) ) {
+		if ( !isset( $this->numeric_version ) ) {
 			$this->getServerVersion();
 		}
 
@@ -980,7 +988,7 @@ __INDEXATTR__;
 		$endArray = array();
 
 		foreach( $result as $table ) {
-			$vars = get_object_vars($table);
+			$vars = get_object_vars( $table );
 			$table = array_pop( $vars );
 			if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 				$endArray[] = $table;
@@ -1052,7 +1060,6 @@ __INDEXATTR__;
 		return '[http://www.postgresql.org/ PostgreSQL]';
 	}
 
-
 	/**
 	 * Return current schema (executes SELECT current_schema())
 	 * Needs transaction
@@ -1061,7 +1068,7 @@ __INDEXATTR__;
 	 * @return string return default schema for the current session
 	 */
 	function getCurrentSchema() {
-		$res = $this->query( "SELECT current_schema()", __METHOD__);
+		$res = $this->query( "SELECT current_schema()", __METHOD__ );
 		$row = $this->fetchRow( $res );
 		return $row[0];
 	}
@@ -1071,17 +1078,17 @@ __INDEXATTR__;
 	 * This is list does not contain magic keywords like "$user"
 	 * Needs transaction
 	 *
-	 * @seealso getSearchPath()
-	 * @seealso setSearchPath()
+	 * @see getSearchPath()
+	 * @see setSearchPath()
 	 * @since 1.19
 	 * @return array list of actual schemas for the current sesson
 	 */
 	function getSchemas() {
-		$res = $this->query( "SELECT current_schemas(false)", __METHOD__);
+		$res = $this->query( "SELECT current_schemas(false)", __METHOD__ );
 		$row = $this->fetchRow( $res );
 		$schemas = array();
 		/* PHP pgsql support does not support array type, "{a,b}" string is returned */
-		return $this->pg_array_parse($row[0], $schemas);
+		return $this->pg_array_parse( $row[0], $schemas );
 	}
 
 	/**
@@ -1094,10 +1101,10 @@ __INDEXATTR__;
 	 * @return array how to search for table names schemas for the current user
 	 */
 	function getSearchPath() {
-		$res = $this->query( "SHOW search_path", __METHOD__);
+		$res = $this->query( "SHOW search_path", __METHOD__ );
 		$row = $this->fetchRow( $res );
 		/* PostgreSQL returns SHOW values as strings */
-		return explode(",", $row[0]);
+		return explode( ",", $row[0] );
 	}
 
 	/**
@@ -1108,7 +1115,7 @@ __INDEXATTR__;
 	 * @param $search_path array list of schemas to be searched by default
 	 */
 	function setSearchPath( $search_path ) {
-		$this->query( "SET search_path = " . implode(", ", $search_path) );
+		$this->query( "SET search_path = " . implode( ", ", $search_path ) );
 	}
 
 	/**
@@ -1129,7 +1136,7 @@ __INDEXATTR__;
 		if ( $this->schemaExists( $desired_schema ) ) {
 			if ( in_array( $desired_schema, $this->getSchemas() ) ) {
 				$this->mCoreSchema = $desired_schema;
-				wfDebug("Schema \"" . $desired_schema . "\" already in the search path\n");
+				wfDebug( "Schema \"" . $desired_schema . "\" already in the search path\n" );
 			} else {
 				/**
 				 * Prepend our schema (e.g. 'mediawiki') in front
@@ -1141,11 +1148,11 @@ __INDEXATTR__;
 					$this->addIdentifierQuotes( $desired_schema ));
 				$this->setSearchPath( $search_path );
 				$this->mCoreSchema = $desired_schema;
-				wfDebug("Schema \"" . $desired_schema . "\" added to the search path\n");
+				wfDebug( "Schema \"" . $desired_schema . "\" added to the search path\n" );
 			}
 		} else {
 			$this->mCoreSchema = $this->getCurrentSchema();
-			wfDebug("Schema \"" . $desired_schema . "\" not found, using current \"". $this->mCoreSchema ."\"\n");
+			wfDebug( "Schema \"" . $desired_schema . "\" not found, using current \"" . $this->mCoreSchema . "\"\n" );
 		}
 		/* Commit SET otherwise it will be rollbacked on error or IGNORE SELECT */
 		$this->commit( __METHOD__ );
@@ -1251,8 +1258,8 @@ SQL;
 	}
 
 	function constraintExists( $table, $constraint ) {
-		$SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints ".
-			   "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
+		$SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints " .
+				"WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
 			$this->addQuotes( $this->getCoreSchema() ),
 			$this->addQuotes( $table ),
 			$this->addQuotes( $constraint )
@@ -1340,7 +1347,7 @@ SQL;
 	 *
 	 * @private
 	 *
-	 * @param $ins String: SQL string, read from a stream (usually tables.sql)
+	 * @param string $ins SQL string, read from a stream (usually tables.sql)
 	 *
 	 * @return string SQL string
 	 */
@@ -1364,7 +1371,7 @@ SQL;
 	 *
 	 * @private
 	 *
-	 * @param $options Array: an associative array of options to be turned into
+	 * @param array $options an associative array of options to be turned into
 	 *              an SQL query, valid keys are listed in the function.
 	 * @return array
 	 */
@@ -1379,23 +1386,9 @@ SQL;
 			}
 		}
 
-		if ( isset( $options['GROUP BY'] ) ) {
-			$gb = is_array( $options['GROUP BY'] )
-				? implode( ',', $options['GROUP BY'] )
-				: $options['GROUP BY'];
-			$preLimitTail .= " GROUP BY {$gb}";
-		}
+		$preLimitTail .= $this->makeGroupByWithHaving( $options );
 
-		if ( isset( $options['HAVING'] ) ) {
-			$preLimitTail .= " HAVING {$options['HAVING']}";
-		}
-
-		if ( isset( $options['ORDER BY'] ) ) {
-			$ob = is_array( $options['ORDER BY'] )
-				? implode( ',', $options['ORDER BY'] )
-				: $options['ORDER BY'];
-			$preLimitTail .= " ORDER BY {$ob}";
-		}
+		$preLimitTail .= $this->makeOrderBy( $options );
 
 		//if ( isset( $options['LIMIT'] ) ) {
 		//	$tailOpts .= $this->limitResult( '', $options['LIMIT'],
@@ -1443,4 +1436,65 @@ SQL;
 		}
 		return parent::streamStatementEnd( $sql, $newLine );
 	}
+
+	/**
+	 * Check to see if a named lock is available. This is non-blocking.
+	 * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
+	 *
+	 * @param string $lockName name of lock to poll
+	 * @param string $method name of method calling us
+	 * @return Boolean
+	 * @since 1.20
+	 */
+	public function lockIsFree( $lockName, $method ) {
+		$key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
+		$result = $this->query( "SELECT (CASE(pg_try_advisory_lock($key))
+			WHEN 'f' THEN 'f' ELSE pg_advisory_unlock($key) END) AS lockstatus", $method );
+		$row = $this->fetchObject( $result );
+		return ( $row->lockstatus === 't' );
+	}
+
+	/**
+	 * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
+	 * @param $lockName string
+	 * @param $method string
+	 * @param $timeout int
+	 * @return bool
+	 */
+	public function lock( $lockName, $method, $timeout = 5 ) {
+		$key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
+		for ( $attempts = 1; $attempts <= $timeout; ++$attempts ) {
+			$result = $this->query(
+				"SELECT pg_try_advisory_lock($key) AS lockstatus", $method );
+			$row = $this->fetchObject( $result );
+			if ( $row->lockstatus === 't' ) {
+				return true;
+			} else {
+				sleep( 1 );
+			}
+		}
+		wfDebug( __METHOD__." failed to acquire lock\n" );
+		return false;
+	}
+
+	/**
+	 * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKSFROM PG DOCS: http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
+	 * @param $lockName string
+	 * @param $method string
+	 * @return bool
+	 */
+	public function unlock( $lockName, $method ) {
+		$key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
+		$result = $this->query( "SELECT pg_advisory_unlock($key) as lockstatus", $method );
+		$row = $this->fetchObject( $result );
+		return ( $row->lockstatus === 't' );
+	}
+
+	/**
+	 * @param string $lockName
+	 * @return string Integer
+	 */
+	private function bigintFromLockName( $lockName ) {
+		return wfBaseConvert( substr( sha1( $lockName ), 0, 15 ), 16, 10 );
+	}
 } // end DatabasePostgres class
diff --git a/includes/db/DatabaseSqlite.php b/includes/db/DatabaseSqlite.php
index f1e553d7..0789e1b1 100644
--- a/includes/db/DatabaseSqlite.php
+++ b/includes/db/DatabaseSqlite.php
@@ -79,11 +79,12 @@ class DatabaseSqlite extends DatabaseBase {
 	/** Open an SQLite database and return a resource handle to it
 	 *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 	 *
-	 * @param $server
-	 * @param $user
-	 * @param $pass
-	 * @param $dbName
+	 * @param string $server
+	 * @param string $user
+	 * @param string $pass
+	 * @param string $dbName
 	 *
+	 * @throws DBConnectionError
 	 * @return PDO
 	 */
 	function open( $server, $user, $pass, $dbName ) {
@@ -103,6 +104,7 @@ class DatabaseSqlite extends DatabaseBase {
 	 *
 	 * @param $fileName string
 	 *
+	 * @throws DBConnectionError
 	 * @return PDO|bool SQL connection or false if failed
 	 */
 	function openFile( $fileName ) {
@@ -125,6 +127,8 @@ class DatabaseSqlite extends DatabaseBase {
 		# set error codes only, don't raise exceptions
 		if ( $this->mOpened ) {
 			$this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
+			# Enforce LIKE to be case sensitive, just like MySQL
+			$this->query( 'PRAGMA case_sensitive_like = 1' );
 			return true;
 		}
 	}
@@ -140,8 +144,8 @@ class DatabaseSqlite extends DatabaseBase {
 
 	/**
 	 * Generates a database file name. Explicitly public for installer.
-	 * @param $dir String: Directory where database resides
-	 * @param $dbName String: Database name
+	 * @param string $dir Directory where database resides
+	 * @param string $dbName Database name
 	 * @return String
 	 */
 	public static function generateFileName( $dir, $dbName ) {
@@ -159,7 +163,7 @@ class DatabaseSqlite extends DatabaseBase {
 			$res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 			if ( $res ) {
 				$row = $res->fetchRow();
-				self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
+				self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 			}
 		}
 		return self::$fulltextEnabled;
@@ -190,9 +194,9 @@ class DatabaseSqlite extends DatabaseBase {
 	 * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 	 * for details.
 	 *
-	 * @param $name String: database name to be used in queries like SELECT foo FROM dbname.table
-	 * @param $file String: database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
-	 * @param $fname String: calling function name
+	 * @param string $name database name to be used in queries like SELECT foo FROM dbname.table
+	 * @param string $file database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
+	 * @param string $fname calling function name
 	 *
 	 * @return ResultWrapper
 	 */
@@ -248,7 +252,7 @@ class DatabaseSqlite extends DatabaseBase {
 
 	/**
 	 * @param $res ResultWrapper
-	 * @return
+	 * @return object|bool
 	 */
 	function fetchObject( $res ) {
 		if ( $res instanceof ResultWrapper ) {
@@ -274,7 +278,7 @@ class DatabaseSqlite extends DatabaseBase {
 
 	/**
 	 * @param $res ResultWrapper
-	 * @return bool|mixed
+	 * @return array|bool
 	 */
 	function fetchRow( $res ) {
 		if ( $res instanceof ResultWrapper ) {
@@ -467,7 +471,7 @@ class DatabaseSqlite extends DatabaseBase {
 	 */
 	function makeSelectOptions( $options ) {
 		foreach ( $options as $k => $v ) {
-			if ( is_numeric( $k ) && $v == 'FOR UPDATE' ) {
+			if ( is_numeric( $k ) && ($v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE') ) {
 				$options[$k] = '';
 			}
 		}
@@ -593,7 +597,7 @@ class DatabaseSqlite extends DatabaseBase {
 	 * @return bool
 	 */
 	function wasErrorReissuable() {
-		return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
+		return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 	}
 
 	/**
@@ -703,6 +707,14 @@ class DatabaseSqlite extends DatabaseBase {
 	function addQuotes( $s ) {
 		if ( $s instanceof Blob ) {
 			return "x'" . bin2hex( $s->fetch() ) . "'";
+		} else if ( strpos( $s, "\0" ) !== false ) {
+			// SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
+			// This is a known limitation of SQLite's mprintf function which PDO should work around,
+			// but doesn't. I have reported this to php.net as bug #63419:
+			// https://bugs.php.net/bug.php?id=63419
+			// There was already a similar report for SQLite3::escapeString, bug #62361:
+			// https://bugs.php.net/bug.php?id=62361
+			return "x'" . bin2hex( $s ) . "'";
 		} else {
 			return $this->mConn->quote( $s );
 		}
@@ -819,12 +831,11 @@ class DatabaseSqlite extends DatabaseBase {
 		return $this->query( $sql, $fname );
 	}
 
-
 	/**
 	 * List all tables on the database
 	 *
-	 * @param $prefix string Only show tables with this prefix, e.g. mw_
-	 * @param $fname String: calling function name
+	 * @param string $prefix Only show tables with this prefix, e.g. mw_
+	 * @param string $fname calling function name
 	 *
 	 * @return array
 	 */
@@ -838,7 +849,7 @@ class DatabaseSqlite extends DatabaseBase {
 		$endArray = array();
 
 		foreach( $result as $table ) {
-			$vars = get_object_vars($table);
+			$vars = get_object_vars( $table );
 			$table = array_pop( $vars );
 
 			if( !$prefix || strpos( $table, $prefix ) === 0 ) {
diff --git a/includes/db/DatabaseUtility.php b/includes/db/DatabaseUtility.php
index c846788d..9a1c8bde 100644
--- a/includes/db/DatabaseUtility.php
+++ b/includes/db/DatabaseUtility.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * This file contains database-related utiliy classes.
+ * This file contains database-related utility classes.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -138,7 +138,7 @@ class ResultWrapper implements Iterator {
 
 	/**
 	 * Fetch the next row from the given result object, in associative array
-	 * form.  Fields are retrieved with $row['fieldname'].
+	 * form. Fields are retrieved with $row['fieldname'].
 	 *
 	 * @return Array
 	 * @throws DBUnexpectedError Thrown if the database returns an error
@@ -219,9 +219,9 @@ class ResultWrapper implements Iterator {
  * doesn't go anywhere near an actual database.
  */
 class FakeResultWrapper extends ResultWrapper {
-	var $result     = array();
-	var $db         = null;	// And it's going to stay that way :D
-	var $pos        = 0;
+	var $result = array();
+	var $db = null; // And it's going to stay that way :D
+	var $pos = 0;
 	var $currentRow = null;
 
 	function __construct( $array ) {
@@ -285,7 +285,7 @@ class LikeMatch {
 	/**
 	 * Store a string into a LikeMatch marker object.
 	 *
-	 * @param String $s
+	 * @param string $s
 	 */
 	public function __construct( $s ) {
 		$this->str = $s;
@@ -306,4 +306,3 @@ class LikeMatch {
  */
 interface DBMasterPos {
 }
-
diff --git a/includes/db/IORMRow.php b/includes/db/IORMRow.php
index e99ba6cc..6bc0cdd2 100644
--- a/includes/db/IORMRow.php
+++ b/includes/db/IORMRow.php
@@ -27,13 +27,12 @@
  * @file
  * @ingroup ORM
  *
- * @licence GNU GPL v2 or later
+ * @license GNU GPL v2 or later
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  */
 
 interface IORMRow {
 
-
 	/**
 	 * Constructor.
 	 *
@@ -272,4 +271,4 @@ interface IORMRow {
 	 */
 	public function getTable();
 
-}
\ No newline at end of file
+}
diff --git a/includes/db/IORMTable.php b/includes/db/IORMTable.php
index 99413f99..36865655 100644
--- a/includes/db/IORMTable.php
+++ b/includes/db/IORMTable.php
@@ -23,7 +23,7 @@
  * @file
  * @ingroup ORM
  *
- * @licence GNU GPL v2 or later
+ * @license GNU GPL v2 or later
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  */
 
@@ -97,6 +97,8 @@ interface IORMTable {
 	 * Selects the the specified fields of the records matching the provided
 	 * conditions and returns them as DBDataObject. Field names get prefixed.
 	 *
+	 * @see DatabaseBase::select()
+	 *
 	 * @since 1.20
 	 *
 	 * @param array|string|null $fields
@@ -104,7 +106,8 @@ interface IORMTable {
 	 * @param array $options
 	 * @param string|null $functionName
 	 *
-	 * @return ORMResult
+	 * @return ORMResult The result set
+	 * @throws DBQueryError if the query failed (even if the database was in ignoreErrors mode)
 	 */
 	public function select( $fields = null, array $conditions = array(),
 							array $options = array(), $functionName = null );
@@ -136,6 +139,7 @@ interface IORMTable {
 	 * @param null|string $functionName
 	 *
 	 * @return ResultWrapper
+	 * @throws DBQueryError if the query failed (even if the database was in ignoreErrors mode)
 	 */
 	public function rawSelect( $fields = null, array $conditions = array(),
 							   array $options = array(), $functionName = null );
@@ -230,6 +234,15 @@ interface IORMTable {
 	public function has( array $conditions = array() );
 
 	/**
+	 * Checks if the table exists
+	 *
+	 * @since 1.21
+	 *
+	 * @return boolean
+	 */
+	public function exists();
+
+	/**
 	 * Returns the amount of matching records.
 	 * Condition field names get prefixed.
 	 *
@@ -299,6 +312,71 @@ interface IORMTable {
 	public function setReadDb( $db );
 
 	/**
+	 * Get the ID of the any foreign wiki to use as a target for database operations
+	 *
+	 * @since 1.20
+	 *
+	 * @return String|bool The target wiki, in a form that  LBFactory understands (or false if the local wiki is used)
+	 */
+	public function getTargetWiki();
+
+	/**
+	 * Set the ID of the any foreign wiki to use as a target for database operations
+	 *
+	 * @param string|bool $wiki The target wiki, in a form that  LBFactory understands (or false if the local wiki shall be used)
+	 *
+	 * @since 1.20
+	 */
+	public function setTargetWiki( $wiki );
+
+	/**
+	 * Get the database type used for read operations.
+	 * This is to be used instead of wfGetDB.
+	 *
+	 * @see LoadBalancer::getConnection
+	 *
+	 * @since 1.20
+	 *
+	 * @return DatabaseBase The database object
+	 */
+	public function getReadDbConnection();
+
+	/**
+	 * Get the database type used for read operations.
+	 * This is to be used instead of wfGetDB.
+	 *
+	 * @see LoadBalancer::getConnection
+	 *
+	 * @since 1.20
+	 *
+	 * @return DatabaseBase The database object
+	 */
+	public function getWriteDbConnection();
+
+	/**
+	 * Get the database type used for read operations.
+	 *
+	 * @see wfGetLB
+	 *
+	 * @since 1.20
+	 *
+	 * @return LoadBalancer The database load balancer object
+	 */
+	public function getLoadBalancer();
+
+	/**
+	 * Releases the lease on the given database connection. This is useful mainly
+	 * for connections to a foreign wiki. It does nothing for connections to the local wiki.
+	 *
+	 * @see LoadBalancer::reuseConnection
+	 *
+	 * @param DatabaseBase $db the database
+	 *
+	 * @since 1.20
+	 */
+	public function releaseConnection( DatabaseBase $db );
+
+	/**
 	 * Update the records matching the provided conditions by
 	 * setting the fields that are keys in the $values param to
 	 * their corresponding values.
@@ -381,15 +459,6 @@ interface IORMTable {
 	public function unprefixFieldName( $fieldName );
 
 	/**
-	 * Get an instance of this class.
-	 *
-	 * @since 1.20
-	 *
-	 * @return IORMTable
-	 */
-	public static function singleton();
-
-	/**
 	 * Get an array with fields from a database result,
 	 * that can be fed directly to the constructor or
 	 * to setFields.
diff --git a/includes/db/LBFactory.php b/includes/db/LBFactory.php
index e82c54ba..d469e867 100644
--- a/includes/db/LBFactory.php
+++ b/includes/db/LBFactory.php
@@ -86,7 +86,7 @@ abstract class LBFactory {
 	 * Create a new load balancer object. The resulting object will be untracked,
 	 * not chronology-protected, and the caller is responsible for cleaning it up.
 	 *
-	 * @param $wiki String: wiki ID, or false for the current wiki
+	 * @param string $wiki wiki ID, or false for the current wiki
 	 * @return LoadBalancer
 	 */
 	abstract function newMainLB( $wiki = false );
@@ -94,7 +94,7 @@ abstract class LBFactory {
 	/**
 	 * Get a cached (tracked) load balancer object.
 	 *
-	 * @param $wiki String: wiki ID, or false for the current wiki
+	 * @param string $wiki wiki ID, or false for the current wiki
 	 * @return LoadBalancer
 	 */
 	abstract function getMainLB( $wiki = false );
@@ -104,8 +104,8 @@ abstract class LBFactory {
 	 * untracked, not chronology-protected, and the caller is responsible for
 	 * cleaning it up.
 	 *
-	 * @param $cluster String: external storage cluster, or false for core
-	 * @param $wiki String: wiki ID, or false for the current wiki
+	 * @param string $cluster external storage cluster, or false for core
+	 * @param string $wiki wiki ID, or false for the current wiki
 	 *
 	 * @return LoadBalancer
 	 */
@@ -114,8 +114,8 @@ abstract class LBFactory {
 	/**
 	 * Get a cached (tracked) load balancer for external storage
 	 *
-	 * @param $cluster String: external storage cluster, or false for core
-	 * @param $wiki String: wiki ID, or false for the current wiki
+	 * @param string $cluster external storage cluster, or false for core
+	 * @param string $wiki wiki ID, or false for the current wiki
 	 *
 	 * @return LoadBalancer
 	 */
@@ -240,7 +240,7 @@ class LBFactory_Simple extends LBFactory {
 	function newExternalLB( $cluster, $wiki = false ) {
 		global $wgExternalServers;
 		if ( !isset( $wgExternalServers[$cluster] ) ) {
-			throw new MWException( __METHOD__.": Unknown cluster \"$cluster\"" );
+			throw new MWException( __METHOD__ . ": Unknown cluster \"$cluster\"" );
 		}
 		return new LoadBalancer( array(
 			'servers' => $wgExternalServers[$cluster]
@@ -345,7 +345,7 @@ class ChronologyProtector {
 		if ( $lb->getServerCount() > 1 && !empty( $this->startupPos[$masterName] ) ) {
 			$info = $lb->parentInfo();
 			$pos = $this->startupPos[$masterName];
-			wfDebug( __METHOD__.": LB " . $info['id'] . " waiting for master pos $pos\n" );
+			wfDebug( __METHOD__ . ": LB " . $info['id'] . " waiting for master pos $pos\n" );
 			$lb->waitFor( $this->startupPos[$masterName] );
 		}
 	}
@@ -370,11 +370,11 @@ class ChronologyProtector {
 		$db = $lb->getAnyOpenConnection( 0 );
 		$info = $lb->parentInfo();
 		if ( !$db || !$db->doneWrites() ) {
-			wfDebug( __METHOD__.": LB {$info['id']}, no writes done\n" );
+			wfDebug( __METHOD__ . ": LB {$info['id']}, no writes done\n" );
 			return;
 		}
 		$pos = $db->getMasterPos();
-		wfDebug( __METHOD__.": LB {$info['id']} has master pos $pos\n" );
+		wfDebug( __METHOD__ . ": LB {$info['id']} has master pos $pos\n" );
 		$this->shutdownPos[$masterName] = $pos;
 	}
 
@@ -384,7 +384,7 @@ class ChronologyProtector {
 	 */
 	function shutdown() {
 		if ( session_id() != '' && count( $this->shutdownPos ) ) {
-			wfDebug( __METHOD__.": saving master pos for " .
+			wfDebug( __METHOD__ . ": saving master pos for " .
 				count( $this->shutdownPos ) . " master(s)\n" );
 			$_SESSION[__CLASS__] = $this->shutdownPos;
 		}
diff --git a/includes/db/LBFactory_Multi.php b/includes/db/LBFactory_Multi.php
index 6008813b..2e4963d4 100644
--- a/includes/db/LBFactory_Multi.php
+++ b/includes/db/LBFactory_Multi.php
@@ -21,7 +21,6 @@
  * @ingroup Database
  */
 
-
 /**
  * A multi-wiki, multi-master factory for Wikimedia and similar installations.
  * Ignores the old configuration globals
@@ -70,6 +69,7 @@ class LBFactory_Multi extends LBFactory {
 
 	/**
 	 * @param $conf array
+	 * @throws MWException
 	 */
 	function __construct( $conf ) {
 		$this->chronProt = new ChronologyProtector;
@@ -82,7 +82,7 @@ class LBFactory_Multi extends LBFactory {
 
 		foreach ( $required as $key ) {
 			if ( !isset( $conf[$key] ) ) {
-				throw new MWException( __CLASS__.": $key is required in configuration" );
+				throw new MWException( __CLASS__ . ": $key is required in configuration" );
 			}
 			$this->$key = $conf[$key];
 		}
@@ -153,13 +153,14 @@ class LBFactory_Multi extends LBFactory {
 	}
 
 	/**
-	 * @param $cluster
-	 * @param $wiki
+	 * @param string $cluster
+	 * @param bool $wiki
+	 * @throws MWException
 	 * @return LoadBalancer
 	 */
 	function newExternalLB( $cluster, $wiki = false ) {
 		if ( !isset( $this->externalLoads[$cluster] ) ) {
-			throw new MWException( __METHOD__.": Unknown cluster \"$cluster\"" );
+			throw new MWException( __METHOD__ . ": Unknown cluster \"$cluster\"" );
 		}
 		$template = $this->serverTemplate;
 		if ( isset( $this->externalTemplateOverrides ) ) {
diff --git a/includes/db/LBFactory_Single.php b/includes/db/LBFactory_Single.php
index 4b165b2a..7dca06d7 100644
--- a/includes/db/LBFactory_Single.php
+++ b/includes/db/LBFactory_Single.php
@@ -28,7 +28,7 @@ class LBFactory_Single extends LBFactory {
 	protected $lb;
 
 	/**
-	 * @param $conf array An associative array with one member:
+	 * @param array $conf An associative array with one member:
 	 *  - connection: The DatabaseBase connection object
 	 */
 	function __construct( $conf ) {
diff --git a/includes/db/LoadBalancer.php b/includes/db/LoadBalancer.php
index 0e455e0c..1e859278 100644
--- a/includes/db/LoadBalancer.php
+++ b/includes/db/LoadBalancer.php
@@ -37,14 +37,15 @@ class LoadBalancer {
 	private $mLoadMonitorClass, $mLoadMonitor;
 
 	/**
-	 * @param $params Array with keys:
+	 * @param array $params with keys:
 	 *    servers           Required. Array of server info structures.
 	 *    masterWaitTimeout Replication lag wait timeout
 	 *    loadMonitor       Name of a class used to fetch server lag and load.
+	 * @throws MWException
 	 */
 	function __construct( $params ) {
 		if ( !isset( $params['servers'] ) ) {
-			throw new MWException( __CLASS__.': missing servers parameter' );
+			throw new MWException( __CLASS__ . ': missing servers parameter' );
 		}
 		$this->mServers = $params['servers'];
 
@@ -116,34 +117,14 @@ class LoadBalancer {
 	 * Given an array of non-normalised probabilities, this function will select
 	 * an element and return the appropriate key
 	 *
+	 * @deprecated 1.21, use ArrayUtils::pickRandom()
+	 *
 	 * @param $weights array
 	 *
-	 * @return int
+	 * @return bool|int|string
 	 */
 	function pickRandom( $weights ) {
-		if ( !is_array( $weights ) || count( $weights ) == 0 ) {
-			return false;
-		}
-
-		$sum = array_sum( $weights );
-		if ( $sum == 0 ) {
-			# No loads on any of them
-			# In previous versions, this triggered an unweighted random selection,
-			# but this feature has been removed as of April 2006 to allow for strict
-			# separation of query groups.
-			return false;
-		}
-		$max = mt_getrandmax();
-		$rand = mt_rand( 0, $max ) / $max * $sum;
-
-		$sum = 0;
-		foreach ( $weights as $i => $w ) {
-			$sum += $w;
-			if ( $sum >= $rand ) {
-				break;
-			}
-		}
-		return $i;
+		return ArrayUtils::pickRandom( $weights );
 	}
 
 	/**
@@ -197,17 +178,18 @@ class LoadBalancer {
 	 * Side effect: opens connections to databases
 	 * @param $group bool
 	 * @param $wiki bool
+	 * @throws MWException
 	 * @return bool|int|string
 	 */
 	function getReaderIndex( $group = false, $wiki = false ) {
 		global $wgReadOnly, $wgDBClusterTimeout, $wgDBAvgStatusPoll, $wgDBtype;
 
 		# @todo FIXME: For now, only go through all this for mysql databases
-		if ($wgDBtype != 'mysql') {
+		if ( $wgDBtype != 'mysql' ) {
 			return $this->getWriterIndex();
 		}
 
-		if ( count( $this->mServers ) == 1 )  {
+		if ( count( $this->mServers ) == 1 ) {
 			# Skip the load balancing if there's only one server
 			return 0;
 		} elseif ( $group === false and $this->mReadIndex >= 0 ) {
@@ -228,7 +210,7 @@ class LoadBalancer {
 				$nonErrorLoads = $this->mGroupLoads[$group];
 			} else {
 				# No loads for this group, return false and the caller can use some other group
-				wfDebug( __METHOD__.": no loads for group $group\n" );
+				wfDebug( __METHOD__ . ": no loads for group $group\n" );
 				wfProfileOut( __METHOD__ );
 				return false;
 			}
@@ -256,7 +238,7 @@ class LoadBalancer {
 					$i = $this->pickRandom( $currentLoads );
 				} else {
 					$i = $this->getRandomNonLagged( $currentLoads, $wiki );
-					if ( $i === false && count( $currentLoads ) != 0 )  {
+					if ( $i === false && count( $currentLoads ) != 0 ) {
 						# All slaves lagged. Switch to read-only mode
 						wfDebugLog( 'replication', "All slaves lagged. Switch to read-only mode\n" );
 						$wgReadOnly = 'The database has been automatically locked ' .
@@ -270,16 +252,16 @@ class LoadBalancer {
 					# pickRandom() returned false
 					# This is permanent and means the configuration or the load monitor
 					# wants us to return false.
-					wfDebugLog( 'connect', __METHOD__.": pickRandom() returned false\n" );
+					wfDebugLog( 'connect', __METHOD__ . ": pickRandom() returned false\n" );
 					wfProfileOut( __METHOD__ );
 					return false;
 				}
 
-				wfDebugLog( 'connect', __METHOD__.": Using reader #$i: {$this->mServers[$i]['host']}...\n" );
+				wfDebugLog( 'connect', __METHOD__ . ": Using reader #$i: {$this->mServers[$i]['host']}...\n" );
 				$conn = $this->openConnection( $i, $wiki );
 
 				if ( !$conn ) {
-					wfDebugLog( 'connect', __METHOD__.": Failed connecting to $i/$wiki\n" );
+					wfDebugLog( 'connect', __METHOD__ . ": Failed connecting to $i/$wiki\n" );
 					unset( $nonErrorLoads[$i] );
 					unset( $currentLoads[$i] );
 					continue;
@@ -318,7 +300,7 @@ class LoadBalancer {
 
 			# Some servers must have been overloaded
 			if ( $overloadedServers == 0 ) {
-				throw new MWException( __METHOD__.": unexpectedly found no overloaded servers" );
+				throw new MWException( __METHOD__ . ": unexpectedly found no overloaded servers" );
 			}
 			# Back off for a while
 			# Scale the sleep time by the number of connected threads, to produce a
@@ -341,7 +323,7 @@ class LoadBalancer {
 					$this->mServers[$i]['slave pos'] = $conn->getSlavePos();
 				}
 			}
-			if ( $this->mReadIndex <=0 && $this->mLoads[$i]>0 && $i !== false ) {
+			if ( $this->mReadIndex <= 0 && $this->mLoads[$i] > 0 && $i !== false ) {
 				$this->mReadIndex = $i;
 			}
 		}
@@ -356,7 +338,7 @@ class LoadBalancer {
 	 */
 	function sleep( $t ) {
 		wfProfileIn( __METHOD__ );
-		wfDebug( __METHOD__.": waiting $t us\n" );
+		wfDebug( __METHOD__ . ": waiting $t us\n" );
 		usleep( $t );
 		wfProfileOut( __METHOD__ );
 		return $t;
@@ -390,7 +372,7 @@ class LoadBalancer {
 		wfProfileIn( __METHOD__ );
 		$this->mWaitForPos = $pos;
 		for ( $i = 1; $i < count( $this->mServers ); $i++ ) {
-			$this->doWait( $i , true );
+			$this->doWait( $i, true );
 		}
 		wfProfileOut( __METHOD__ );
 	}
@@ -433,15 +415,15 @@ class LoadBalancer {
 			}
 		}
 
-		wfDebug( __METHOD__.": Waiting for slave #$index to catch up...\n" );
+		wfDebug( __METHOD__ . ": Waiting for slave #$index to catch up...\n" );
 		$result = $conn->masterPosWait( $this->mWaitForPos, $this->mWaitTimeout );
 
 		if ( $result == -1 || is_null( $result ) ) {
 			# Timed out waiting for slave, use master instead
-			wfDebug( __METHOD__.": Timed out waiting for slave #$index pos {$this->mWaitForPos}\n" );
+			wfDebug( __METHOD__ . ": Timed out waiting for slave #$index pos {$this->mWaitForPos}\n" );
 			return false;
 		} else {
-			wfDebug( __METHOD__.": Done\n" );
+			wfDebug( __METHOD__ . ": Done\n" );
 			return true;
 		}
 	}
@@ -451,9 +433,10 @@ class LoadBalancer {
 	 * This is the main entry point for this class.
 	 *
 	 * @param $i Integer: server index
-	 * @param $groups Array: query groups
-	 * @param $wiki String: wiki ID
+	 * @param array $groups query groups
+	 * @param bool|string $wiki Wiki ID
 	 *
+	 * @throws MWException
 	 * @return DatabaseBase
 	 */
 	public function &getConnection( $i, $groups = array(), $wiki = false ) {
@@ -476,7 +459,7 @@ class LoadBalancer {
 			$groupIndex = $this->getReaderIndex( $groups, $wiki );
 			if ( $groupIndex !== false ) {
 				$serverName = $this->getServerName( $groupIndex );
-				wfDebug( __METHOD__.": using server $serverName for group $groups\n" );
+				wfDebug( __METHOD__ . ": using server $serverName for group $groups\n" );
 				$i = $groupIndex;
 			}
 		} else {
@@ -484,7 +467,7 @@ class LoadBalancer {
 				$groupIndex = $this->getReaderIndex( $group, $wiki );
 				if ( $groupIndex !== false ) {
 					$serverName = $this->getServerName( $groupIndex );
-					wfDebug( __METHOD__.": using server $serverName for group $group\n" );
+					wfDebug( __METHOD__ . ": using server $serverName for group $group\n" );
 					$i = $groupIndex;
 					break;
 				}
@@ -497,16 +480,16 @@ class LoadBalancer {
 			# Couldn't find a working server in getReaderIndex()?
 			if ( $i === false ) {
 				$this->mLastError = 'No working slave server: ' . $this->mLastError;
-				$this->reportConnectionError( $this->mErrorConnection );
 				wfProfileOut( __METHOD__ );
-				return false;
+				return $this->reportConnectionError();
 			}
 		}
 
 		# Now we have an explicit index into the servers array
 		$conn = $this->openConnection( $i, $wiki );
 		if ( !$conn ) {
-			$this->reportConnectionError( $this->mErrorConnection );
+			wfProfileOut( __METHOD__ );
+			return $this->reportConnectionError();
 		}
 
 		wfProfileOut( __METHOD__ );
@@ -519,10 +502,11 @@ class LoadBalancer {
 	 * the same number of times as getConnection() to work.
 	 *
 	 * @param DatabaseBase $conn
+	 * @throws MWException
 	 */
 	public function reuseConnection( $conn ) {
-		$serverIndex = $conn->getLBInfo('serverIndex');
-		$refCount = $conn->getLBInfo('foreignPoolRefCount');
+		$serverIndex = $conn->getLBInfo( 'serverIndex' );
+		$refCount = $conn->getLBInfo( 'foreignPoolRefCount' );
 		$dbName = $conn->getDBname();
 		$prefix = $conn->tablePrefix();
 		if ( strval( $prefix ) !== '' ) {
@@ -531,7 +515,7 @@ class LoadBalancer {
 			$wiki = $dbName;
 		}
 		if ( $serverIndex === null || $refCount === null ) {
-			wfDebug( __METHOD__.": this connection was not opened as a foreign connection\n" );
+			wfDebug( __METHOD__ . ": this connection was not opened as a foreign connection\n" );
 			/**
 			 * This can happen in code like:
 			 *   foreach ( $dbs as $db ) {
@@ -545,15 +529,15 @@ class LoadBalancer {
 			return;
 		}
 		if ( $this->mConns['foreignUsed'][$serverIndex][$wiki] !== $conn ) {
-			throw new MWException( __METHOD__.": connection not found, has the connection been freed already?" );
+			throw new MWException( __METHOD__ . ": connection not found, has the connection been freed already?" );
 		}
 		$conn->setLBInfo( 'foreignPoolRefCount', --$refCount );
 		if ( $refCount <= 0 ) {
 			$this->mConns['foreignFree'][$serverIndex][$wiki] = $conn;
 			unset( $this->mConns['foreignUsed'][$serverIndex][$wiki] );
-			wfDebug( __METHOD__.": freed connection $serverIndex/$wiki\n" );
+			wfDebug( __METHOD__ . ": freed connection $serverIndex/$wiki\n" );
 		} else {
-			wfDebug( __METHOD__.": reference count for $serverIndex/$wiki reduced to $refCount\n" );
+			wfDebug( __METHOD__ . ": reference count for $serverIndex/$wiki reduced to $refCount\n" );
 		}
 	}
 
@@ -566,7 +550,7 @@ class LoadBalancer {
 	 * error will be available via $this->mErrorConnection.
 	 *
 	 * @param $i Integer server index
-	 * @param $wiki String wiki ID to open
+	 * @param string $wiki wiki ID to open
 	 * @return DatabaseBase
 	 *
 	 * @access private
@@ -575,7 +559,7 @@ class LoadBalancer {
 		wfProfileIn( __METHOD__ );
 		if ( $wiki !== false ) {
 			$conn = $this->openForeignConnection( $i, $wiki );
-			wfProfileOut( __METHOD__);
+			wfProfileOut( __METHOD__ );
 			return $conn;
 		}
 		if ( isset( $this->mConns['local'][$i][0] ) ) {
@@ -585,6 +569,7 @@ class LoadBalancer {
 			$server['serverIndex'] = $i;
 			$conn = $this->reallyOpenConnection( $server, false );
 			if ( $conn->isOpen() ) {
+				wfDebug( "Connected to database $i at {$this->mServers[$i]['host']}\n" );
 				$this->mConns['local'][$i][0] = $conn;
 			} else {
 				wfDebug( "Failed to connect to database $i at {$this->mServers[$i]['host']}\n" );
@@ -611,22 +596,22 @@ class LoadBalancer {
 	 * error will be available via $this->mErrorConnection.
 	 *
 	 * @param $i Integer: server index
-	 * @param $wiki String: wiki ID to open
+	 * @param string $wiki wiki ID to open
 	 * @return DatabaseBase
 	 */
 	function openForeignConnection( $i, $wiki ) {
-		wfProfileIn(__METHOD__);
+		wfProfileIn( __METHOD__ );
 		list( $dbName, $prefix ) = wfSplitWikiID( $wiki );
 		if ( isset( $this->mConns['foreignUsed'][$i][$wiki] ) ) {
 			// Reuse an already-used connection
 			$conn = $this->mConns['foreignUsed'][$i][$wiki];
-			wfDebug( __METHOD__.": reusing connection $i/$wiki\n" );
+			wfDebug( __METHOD__ . ": reusing connection $i/$wiki\n" );
 		} elseif ( isset( $this->mConns['foreignFree'][$i][$wiki] ) ) {
 			// Reuse a free connection for the same wiki
 			$conn = $this->mConns['foreignFree'][$i][$wiki];
 			unset( $this->mConns['foreignFree'][$i][$wiki] );
 			$this->mConns['foreignUsed'][$i][$wiki] = $conn;
-			wfDebug( __METHOD__.": reusing free connection $i/$wiki\n" );
+			wfDebug( __METHOD__ . ": reusing free connection $i/$wiki\n" );
 		} elseif ( !empty( $this->mConns['foreignFree'][$i] ) ) {
 			// Reuse a connection from another wiki
 			$conn = reset( $this->mConns['foreignFree'][$i] );
@@ -641,7 +626,7 @@ class LoadBalancer {
 				$conn->tablePrefix( $prefix );
 				unset( $this->mConns['foreignFree'][$i][$oldWiki] );
 				$this->mConns['foreignUsed'][$i][$wiki] = $conn;
-				wfDebug( __METHOD__.": reusing free connection from $oldWiki for $wiki\n" );
+				wfDebug( __METHOD__ . ": reusing free connection from $oldWiki for $wiki\n" );
 			}
 		} else {
 			// Open a new connection
@@ -650,13 +635,13 @@ class LoadBalancer {
 			$server['foreignPoolRefCount'] = 0;
 			$conn = $this->reallyOpenConnection( $server, $dbName );
 			if ( !$conn->isOpen() ) {
-				wfDebug( __METHOD__.": error opening connection for $i/$wiki\n" );
+				wfDebug( __METHOD__ . ": error opening connection for $i/$wiki\n" );
 				$this->mErrorConnection = $conn;
 				$conn = false;
 			} else {
 				$conn->tablePrefix( $prefix );
 				$this->mConns['foreignUsed'][$i][$wiki] = $conn;
-				wfDebug( __METHOD__.": opened new connection for $i/$wiki\n" );
+				wfDebug( __METHOD__ . ": opened new connection for $i/$wiki\n" );
 			}
 		}
 
@@ -665,7 +650,7 @@ class LoadBalancer {
 			$refCount = $conn->getLBInfo( 'foreignPoolRefCount' );
 			$conn->setLBInfo( 'foreignPoolRefCount', $refCount + 1 );
 		}
-		wfProfileOut(__METHOD__);
+		wfProfileOut( __METHOD__ );
 		return $conn;
 	}
 
@@ -690,6 +675,7 @@ class LoadBalancer {
 	 *
 	 * @param $server
 	 * @param $dbNameOverride bool
+	 * @throws MWException
 	 * @return DatabaseBase
 	 */
 	function reallyOpenConnection( $server, $dbNameOverride = false ) {
@@ -698,15 +684,11 @@ class LoadBalancer {
 				'See DefaultSettings.php entry for $wgDBservers.' );
 		}
 
-		$host = $server['host'];
-		$dbname = $server['dbname'];
-
 		if ( $dbNameOverride !== false ) {
-			$server['dbname'] = $dbname = $dbNameOverride;
+			$server['dbname'] = $dbNameOverride;
 		}
 
 		# Create object
-		wfDebug( "Connecting to $host $dbname...\n" );
 		try {
 			$db = DatabaseBase::factory( $server['type'], $server );
 		} catch ( DBConnectionError $e ) {
@@ -715,11 +697,6 @@ class LoadBalancer {
 			$db = $e->db;
 		}
 
-		if ( $db->isOpen() ) {
-			wfDebug( "Connected to $host $dbname.\n" );
-		} else {
-			wfDebug( "Connection failed to $host $dbname.\n" );
-		}
 		$db->setLBInfo( $server );
 		if ( isset( $server['fakeSlaveLag'] ) ) {
 			$db->setFakeSlaveLag( $server['fakeSlaveLag'] );
@@ -731,24 +708,24 @@ class LoadBalancer {
 	}
 
 	/**
-	 * @param $conn
 	 * @throws DBConnectionError
+	 * @return bool
 	 */
-	function reportConnectionError( &$conn ) {
-		wfProfileIn( __METHOD__ );
+	private function reportConnectionError() {
+		$conn = $this->mErrorConnection; // The connection which caused the error
 
 		if ( !is_object( $conn ) ) {
 			// No last connection, probably due to all servers being too busy
 			wfLogDBError( "LB failure with no last connection. Connection error: {$this->mLastError}\n" );
-			$conn = new Database;
+
 			// If all servers were busy, mLastError will contain something sensible
-			throw new DBConnectionError( $conn, $this->mLastError );
+			throw new DBConnectionError( null, $this->mLastError );
 		} else {
 			$server = $conn->getProperty( 'mServer' );
 			wfLogDBError( "Connection error: {$this->mLastError} ({$server})\n" );
-			$conn->reportConnectionError( "{$this->mLastError} ({$server})" );
+			$conn->reportConnectionError( "{$this->mLastError} ({$server})" ); // throws DBConnectionError
 		}
-		wfProfileOut( __METHOD__ );
+		return false; /* not reached */
 	}
 
 	/**
@@ -909,7 +886,9 @@ class LoadBalancer {
 		foreach ( $this->mConns as $conns2 ) {
 			foreach ( $conns2 as $conns3 ) {
 				foreach ( $conns3 as $conn ) {
-					$conn->commit( __METHOD__ );
+					if ( $conn->trxLevel() ) {
+						$conn->commit( __METHOD__, 'flush' );
+					}
 				}
 			}
 		}
@@ -926,8 +905,8 @@ class LoadBalancer {
 				continue;
 			}
 			foreach ( $conns2[$masterIndex] as $conn ) {
-				if ( $conn->writesOrCallbacksPending() ) {
-					$conn->commit( __METHOD__ );
+				if ( $conn->trxLevel() && $conn->writesOrCallbacksPending() ) {
+					$conn->commit( __METHOD__, 'flush' );
 				}
 			}
 		}
@@ -954,10 +933,11 @@ class LoadBalancer {
 	 * @return bool
 	 */
 	function allowLagged( $mode = null ) {
-		if ( $mode === null) {
+		if ( $mode === null ) {
 			return $this->mAllowLagged;
 		}
 		$this->mAllowLagged = $mode;
+		return $this->mAllowLagged;
 	}
 
 	/**
@@ -999,7 +979,7 @@ class LoadBalancer {
 	 * May attempt to open connections to slaves on the default DB. If there is
 	 * no lag, the maximum lag will be reported as -1.
 	 *
-	 * @param $wiki string Wiki ID, or false for the default database
+	 * @param string $wiki Wiki ID, or false for the default database
 	 *
 	 * @return array ( host, max lag, index of max lagged host )
 	 */
diff --git a/includes/db/LoadMonitor.php b/includes/db/LoadMonitor.php
index 146ac61e..ad7b3b2f 100644
--- a/includes/db/LoadMonitor.php
+++ b/includes/db/LoadMonitor.php
@@ -37,7 +37,7 @@ interface LoadMonitor {
 	/**
 	 * Perform pre-connection load ratio adjustment.
 	 * @param $loads array
-	 * @param $group String: the selected query group
+	 * @param string $group the selected query group
 	 * @param $wiki String
 	 */
 	function scaleLoads( &$loads, $group = false, $wiki = false );
@@ -159,7 +159,7 @@ class LoadMonitor_MySQL implements LoadMonitor {
 
 		$times = array();
 		foreach ( $serverIndexes as $i ) {
-			if ($i == 0) { # Master
+			if ( $i == 0 ) { # Master
 				$times[$i] = 0;
 			} elseif ( false !== ( $conn = $this->parent->getAnyOpenConnection( $i ) ) ) {
 				$times[$i] = $conn->getLag();
@@ -173,7 +173,7 @@ class LoadMonitor_MySQL implements LoadMonitor {
 		$wgMemc->set( $memcKey, $times, $expiry );
 
 		# But don't give the timestamp to the caller
-		unset($times['timestamp']);
+		unset( $times['timestamp'] );
 		$lagTimes = $times;
 
 		wfProfileOut( __METHOD__ );
@@ -189,7 +189,7 @@ class LoadMonitor_MySQL implements LoadMonitor {
 		if ( !$threshold ) {
 			return 0;
 		}
-		$status = $conn->getMysqlStatus("Thread%");
+		$status = $conn->getMysqlStatus( "Thread%" );
 		if ( $status['Threads_running'] > $threshold ) {
 			$server = $conn->getProperty( 'mServer' );
 			wfLogDBError( "LB backoff from $server - Threads_running = {$status['Threads_running']}\n" );
@@ -199,4 +199,3 @@ class LoadMonitor_MySQL implements LoadMonitor {
 		}
 	}
 }
-
diff --git a/includes/db/ORMIterator.php b/includes/db/ORMIterator.php
index 090b8932..077eab0f 100644
--- a/includes/db/ORMIterator.php
+++ b/includes/db/ORMIterator.php
@@ -23,9 +23,9 @@
  * @file
  * @ingroup ORM
  *
- * @licence GNU GPL v2 or later
+ * @license GNU GPL v2 or later
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  */
 interface ORMIterator extends Iterator {
 
-}
\ No newline at end of file
+}
diff --git a/includes/db/ORMResult.php b/includes/db/ORMResult.php
index 2a5837a1..160033c4 100644
--- a/includes/db/ORMResult.php
+++ b/includes/db/ORMResult.php
@@ -25,7 +25,7 @@
  * @file ORMResult.php
  * @ingroup ORM
  *
- * @licence GNU GPL v2 or later
+ * @license GNU GPL v2 or later
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  */
 
diff --git a/includes/db/ORMRow.php b/includes/db/ORMRow.php
index 303f3a20..6c1f27ff 100644
--- a/includes/db/ORMRow.php
+++ b/includes/db/ORMRow.php
@@ -27,11 +27,11 @@
  * @file ORMRow.php
  * @ingroup ORM
  *
- * @licence GNU GPL v2 or later
+ * @license GNU GPL v2 or later
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  */
 
-abstract class ORMRow implements IORMRow {
+class ORMRow implements IORMRow {
 
 	/**
 	 * The fields of the object.
@@ -120,7 +120,8 @@ abstract class ORMRow implements IORMRow {
 			$result = $this->table->rawSelectRow(
 				$this->table->getPrefixedFields( $fields ),
 				array( $this->table->getPrefixedField( 'id' ) => $this->getId() ),
-				array( 'LIMIT' => 1 )
+				array( 'LIMIT' => 1 ),
+				__METHOD__
 			);
 
 			if ( $result !== false ) {
@@ -138,8 +139,9 @@ abstract class ORMRow implements IORMRow {
 	 *
 	 * @since 1.20
 	 *
-	 * @param string $name
-	 * @param mixed $default
+	 * @param string $name Field name
+	 * @param $default mixed: Default value to return when none is found
+	 * (default: null)
 	 *
 	 * @throws MWException
 	 * @return mixed
@@ -159,7 +161,7 @@ abstract class ORMRow implements IORMRow {
 	 *
 	 * @since 1.20
 	 *
-	 * @param string$name
+	 * @param $name string
 	 *
 	 * @return mixed
 	 */
@@ -259,11 +261,18 @@ abstract class ORMRow implements IORMRow {
 			if ( array_key_exists( $name, $this->fields ) ) {
 				$value = $this->fields[$name];
 
+				// Skip null id fields so that the DBMS can set the default.
+				if ( $name === 'id' && is_null ( $value ) ) {
+					continue;
+				}
+
 				switch ( $type ) {
 					case 'array':
 						$value = (array)$value;
+						// fall-through!
 					case 'blob':
 						$value = serialize( $value );
+						// fall-through!
 				}
 
 				$values[$this->table->getPrefixedField( $name )] = $value;
@@ -346,7 +355,7 @@ abstract class ORMRow implements IORMRow {
 	 * @return boolean Success indicator
 	 */
 	protected function saveExisting( $functionName = null ) {
-		$dbw = wfGetDB( DB_MASTER );
+		$dbw = $this->table->getWriteDbConnection();
 
 		$success = $dbw->update(
 			$this->table->getName(),
@@ -355,6 +364,8 @@ abstract class ORMRow implements IORMRow {
 			is_null( $functionName ) ? __METHOD__ : $functionName
 		);
 
+		$this->table->releaseConnection( $dbw );
+
 		// DatabaseBase::update does not always return true for success as documented...
 		return $success !== false;
 	}
@@ -382,13 +393,13 @@ abstract class ORMRow implements IORMRow {
 	 * @return boolean Success indicator
 	 */
 	protected function insert( $functionName = null, array $options = null ) {
-		$dbw = wfGetDB( DB_MASTER );
+		$dbw = $this->table->getWriteDbConnection();
 
 		$success = $dbw->insert(
 			$this->table->getName(),
 			$this->getWriteValues(),
 			is_null( $functionName ) ? __METHOD__ : $functionName,
-			is_null( $options ) ? array( 'IGNORE' ) : $options
+			$options
 		);
 
 		// DatabaseBase::insert does not always return true for success as documented...
@@ -398,6 +409,8 @@ abstract class ORMRow implements IORMRow {
 			$this->setField( 'id', $dbw->insertId() );
 		}
 
+		$this->table->releaseConnection( $dbw );
+
 		return $success;
 	}
 
@@ -411,7 +424,7 @@ abstract class ORMRow implements IORMRow {
 	public function remove() {
 		$this->beforeRemove();
 
-		$success = $this->table->delete( array( 'id' => $this->getId() ) );
+		$success = $this->table->delete( array( 'id' => $this->getId() ), __METHOD__ );
 
 		// DatabaseBase::delete does not always return true for success as documented...
 		$success = $success !== false;
@@ -446,8 +459,8 @@ abstract class ORMRow implements IORMRow {
 	}
 
 	/**
-	 * Gets called after successfull removal.
-	 * Can be overriden to get rid of linked data.
+	 * Gets called after successful removal.
+	 * Can be overridden to get rid of linked data.
 	 *
 	 * @since 1.20
 	 */
@@ -501,11 +514,7 @@ abstract class ORMRow implements IORMRow {
 					$value = (float)$value;
 					break;
 				case 'bool':
-					if ( is_string( $value ) ) {
-						$value = $value !== '0';
-					} elseif ( is_int( $value ) ) {
-						$value = $value !== 0;
-					}
+					$value = (bool)$value;
 					break;
 				case 'array':
 					if ( is_string( $value ) ) {
@@ -557,7 +566,7 @@ abstract class ORMRow implements IORMRow {
 		$absoluteAmount = abs( $amount );
 		$isNegative = $amount < 0;
 
-		$dbw = wfGetDB( DB_MASTER );
+		$dbw = $this->table->getWriteDbConnection();
 
 		$fullField = $this->table->getPrefixedField( $field );
 
@@ -572,6 +581,8 @@ abstract class ORMRow implements IORMRow {
 			$this->setField( $field, $this->getField( $field ) + $amount );
 		}
 
+		$this->table->releaseConnection( $dbw );
+
 		return $success;
 	}
 
diff --git a/includes/db/ORMTable.php b/includes/db/ORMTable.php
index a77074ff..bcbe94a3 100644
--- a/includes/db/ORMTable.php
+++ b/includes/db/ORMTable.php
@@ -19,43 +19,150 @@
  * http://www.gnu.org/copyleft/gpl.html
  *
  * @since 1.20
+ * Non-abstract since 1.21
  *
  * @file ORMTable.php
  * @ingroup ORM
  *
- * @licence GNU GPL v2 or later
+ * @license GNU GPL v2 or later
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  */
 
-abstract class ORMTable implements IORMTable {
+class ORMTable extends DBAccessBase implements IORMTable {
 
 	/**
-	 * Gets the db field prefix.
+	 * Cache for instances, used by the singleton method.
 	 *
 	 * @since 1.20
+	 * @deprecated since 1.21
 	 *
-	 * @return string
+	 * @var ORMTable[]
 	 */
-	protected abstract function getFieldPrefix();
+	protected static $instanceCache = array();
 
 	/**
-	 * Cache for instances, used by the singleton method.
+	 * @since 1.21
 	 *
-	 * @since 1.20
-	 * @var array of DBTable
+	 * @var string
 	 */
-	protected static $instanceCache = array();
+	protected $tableName;
+
+	/**
+	 * @since 1.21
+	 *
+	 * @var string[]
+	 */
+	protected $fields = array();
+
+	/**
+	 * @since 1.21
+	 *
+	 * @var string
+	 */
+	protected $fieldPrefix = '';
+
+	/**
+	 * @since 1.21
+	 *
+	 * @var string
+	 */
+	protected $rowClass = 'ORMRow';
 
 	/**
-	 * The database connection to use for read operations.
+	 * @since 1.21
+	 *
+	 * @var array
+	 */
+	protected $defaults = array();
+
+	/**
+	 * ID of the database connection to use for read operations.
 	 * Can be changed via @see setReadDb.
 	 *
 	 * @since 1.20
+	 *
 	 * @var integer DB_ enum
 	 */
 	protected $readDb = DB_SLAVE;
 
 	/**
+	 * Constructor.
+	 *
+	 * @since 1.21
+	 *
+	 * @param string $tableName
+	 * @param string[] $fields
+	 * @param array $defaults
+	 * @param string|null $rowClass
+	 * @param string $fieldPrefix
+	 */
+	public function __construct( $tableName = '', array $fields = array(), array $defaults = array(), $rowClass = null, $fieldPrefix = '' ) {
+		$this->tableName = $tableName;
+		$this->fields = $fields;
+		$this->defaults = $defaults;
+
+		if ( is_string( $rowClass ) ) {
+			$this->rowClass = $rowClass;
+		}
+
+		$this->fieldPrefix = $fieldPrefix;
+	}
+
+	/**
+	 * @see IORMTable::getName
+	 *
+	 * @since 1.21
+	 *
+	 * @return string
+	 * @throws MWException
+	 */
+	public function getName() {
+		if ( $this->tableName === '' ) {
+			throw new MWException( 'The table name needs to be set' );
+		}
+
+		return $this->tableName;
+	}
+
+	/**
+	 * Gets the db field prefix.
+	 *
+	 * @since 1.20
+	 *
+	 * @return string
+	 */
+	protected function getFieldPrefix() {
+		return $this->fieldPrefix;
+	}
+
+	/**
+	 * @see IORMTable::getRowClass
+	 *
+	 * @since 1.21
+	 *
+	 * @return string
+	 */
+	public function getRowClass() {
+		return $this->rowClass;
+	}
+
+	/**
+	 * @see ORMTable::getFields
+	 *
+	 * @since 1.21
+	 *
+	 * @return array
+	 * @throws MWException
+	 */
+	public function getFields() {
+		if ( $this->fields === array() ) {
+			throw new MWException( 'The table needs to have one or more fields' );
+		}
+
+		return $this->fields;
+	}
+
+	/**
 	 * Returns a list of default field values.
 	 * field name => field value
 	 *
@@ -64,7 +171,7 @@ abstract class ORMTable implements IORMTable {
 	 * @return array
 	 */
 	public function getDefaults() {
-		return array();
+		return $this->defaults;
 	}
 
 	/**
@@ -94,8 +201,9 @@ abstract class ORMTable implements IORMTable {
 	 * @return ORMResult
 	 */
 	public function select( $fields = null, array $conditions = array(),
-							array $options = array(), $functionName  = null ) {
-		return new ORMResult( $this, $this->rawSelect( $fields, $conditions, $options, $functionName ) );
+							array $options = array(), $functionName = null ) {
+		$res = $this->rawSelect( $fields, $conditions, $options, $functionName );
+		return new ORMResult( $this, $res );
 	}
 
 	/**
@@ -109,10 +217,11 @@ abstract class ORMTable implements IORMTable {
 	 * @param array $options
 	 * @param string|null $functionName
 	 *
-	 * @return array of self
+	 * @return array of row objects
+	 * @throws DBQueryError if the query failed (even if the database was in ignoreErrors mode).
 	 */
 	public function selectObjects( $fields = null, array $conditions = array(),
-								   array $options = array(), $functionName  = null ) {
+								   array $options = array(), $functionName = null ) {
 		$result = $this->selectFields( $fields, $conditions, $options, false, $functionName );
 
 		$objects = array();
@@ -130,14 +239,15 @@ abstract class ORMTable implements IORMTable {
 	 * @since 1.20
 	 *
 	 * @param null|string|array $fields
-	 * @param array $conditions
-	 * @param array $options
-	 * @param null|string $functionName
+	 * @param array             $conditions
+	 * @param array             $options
+	 * @param null|string       $functionName
 	 *
 	 * @return ResultWrapper
+	 * @throws DBQueryError if the quey failed (even if the database was in ignoreErrors mode).
 	 */
 	public function rawSelect( $fields = null, array $conditions = array(),
-							   array $options = array(), $functionName  = null ) {
+							   array $options = array(), $functionName = null ) {
 		if ( is_null( $fields ) ) {
 			$fields = array_keys( $this->getFields() );
 		}
@@ -145,13 +255,39 @@ abstract class ORMTable implements IORMTable {
 			$fields = (array)$fields;
 		}
 
-		return wfGetDB( $this->getReadDb() )->select(
+		$dbr = $this->getReadDbConnection();
+		$result = $dbr->select(
 			$this->getName(),
 			$this->getPrefixedFields( $fields ),
 			$this->getPrefixedValues( $conditions ),
 			is_null( $functionName ) ? __METHOD__ : $functionName,
 			$options
 		);
+
+		/* @var Exception $error */
+		$error = null;
+
+		if ( $result === false ) {
+			// Database connection was in "ignoreErrors" mode. We don't like that.
+			// So, we emulate the DBQueryError that should have been thrown.
+			$error = new DBQueryError(
+				$dbr,
+				$dbr->lastError(),
+				$dbr->lastErrno(),
+				$dbr->lastQuery(),
+				is_null( $functionName ) ? __METHOD__ : $functionName
+			);
+		}
+
+		$this->releaseConnection( $dbr );
+
+		if ( $error ) {
+			// Note: construct the error before releasing the connection,
+			// but throw it after.
+			throw $error;
+		}
+
+		return $result;
 	}
 
 	/**
@@ -177,7 +313,7 @@ abstract class ORMTable implements IORMTable {
 	 * @return array of array
 	 */
 	public function selectFields( $fields = null, array $conditions = array(),
-								  array $options = array(), $collapse = true, $functionName  = null ) {
+								  array $options = array(), $collapse = true, $functionName = null ) {
 		$objects = array();
 
 		$result = $this->rawSelect( $fields, $conditions, $options, $functionName );
@@ -223,7 +359,7 @@ abstract class ORMTable implements IORMTable {
 
 		$objects = $this->select( $fields, $conditions, $options, $functionName );
 
-		return $objects->isEmpty() ? false : $objects->current();
+		return ( !$objects || $objects->isEmpty() ) ? false : $objects->current();
 	}
 
 	/**
@@ -241,15 +377,18 @@ abstract class ORMTable implements IORMTable {
 	 */
 	public function rawSelectRow( array $fields, array $conditions = array(),
 								  array $options = array(), $functionName = null ) {
-		$dbr = wfGetDB( $this->getReadDb() );
+		$dbr = $this->getReadDbConnection();
 
-		return $dbr->selectRow(
+		$result = $dbr->selectRow(
 			$this->getName(),
 			$fields,
 			$conditions,
 			is_null( $functionName ) ? __METHOD__ : $functionName,
 			$options
 		);
+
+		$this->releaseConnection( $dbr );
+		return $result;
 	}
 
 	/**
@@ -293,6 +432,21 @@ abstract class ORMTable implements IORMTable {
 	}
 
 	/**
+	 * Checks if the table exists
+	 *
+	 * @since 1.21
+	 *
+	 * @return boolean
+	 */
+	public function exists() {
+		$dbr = $this->getReadDbConnection();
+		$exists = $dbr->tableExists( $this->getName() );
+		$this->releaseConnection( $dbr );
+
+		return $exists;
+	}
+
+	/**
 	 * Returns the amount of matching records.
 	 * Condition field names get prefixed.
 	 *
@@ -310,7 +464,8 @@ abstract class ORMTable implements IORMTable {
 		$res = $this->rawSelectRow(
 			array( 'rowcount' => 'COUNT(*)' ),
 			$this->getPrefixedValues( $conditions ),
-			$options
+			$options,
+			__METHOD__
 		);
 
 		return $res->rowcount;
@@ -327,13 +482,18 @@ abstract class ORMTable implements IORMTable {
 	 * @return boolean Success indicator
 	 */
 	public function delete( array $conditions, $functionName = null ) {
-		return wfGetDB( DB_MASTER )->delete(
+		$dbw = $this->getWriteDbConnection();
+
+		$result = $dbw->delete(
 			$this->getName(),
 			$conditions === array() ? '*' : $this->getPrefixedValues( $conditions ),
-			$functionName
+			is_null( $functionName ) ? __METHOD__ : $functionName
 		) !== false; // DatabaseBase::delete does not always return true for success as documented...
+
+		$this->releaseConnection( $dbw );
+		return $result;
 	}
-	
+
 	/**
 	 * Get API parameters for the fields supported by this object.
 	 *
@@ -397,7 +557,7 @@ abstract class ORMTable implements IORMTable {
 	}
 
 	/**
-	 * Get the database type used for read operations.
+	 * Get the database ID used for read operations.
 	 *
 	 * @since 1.20
 	 *
@@ -408,7 +568,7 @@ abstract class ORMTable implements IORMTable {
 	}
 
 	/**
-	 * Set the database type to use for read operations.
+	 * Set the database ID to use for read operations, use DB_XXX constants or an index to the load balancer setup.
 	 *
 	 * @param integer $db
 	 *
@@ -419,6 +579,70 @@ abstract class ORMTable implements IORMTable {
 	}
 
 	/**
+	 * Get the ID of the any foreign wiki to use as a target for database operations
+	 *
+	 * @since 1.20
+	 *
+	 * @return String|bool The target wiki, in a form that  LBFactory understands (or false if the local wiki is used)
+	 */
+	public function getTargetWiki() {
+		return $this->wiki;
+	}
+
+	/**
+	 * Set the ID of the any foreign wiki to use as a target for database operations
+	 *
+	 * @param string|bool $wiki The target wiki, in a form that  LBFactory understands (or false if the local wiki shall be used)
+	 *
+	 * @since 1.20
+	 */
+	public function setTargetWiki( $wiki ) {
+		$this->wiki = $wiki;
+	}
+
+	/**
+	 * Get the database type used for read operations.
+	 * This is to be used instead of wfGetDB.
+	 *
+	 * @see LoadBalancer::getConnection
+	 *
+	 * @since 1.20
+	 *
+	 * @return DatabaseBase The database object
+	 */
+	public function getReadDbConnection() {
+		return $this->getConnection( $this->getReadDb(), array() );
+	}
+
+	/**
+	 * Get the database type used for read operations.
+	 * This is to be used instead of wfGetDB.
+	 *
+	 * @see LoadBalancer::getConnection
+	 *
+	 * @since 1.20
+	 *
+	 * @return DatabaseBase The database object
+	 */
+	public function getWriteDbConnection() {
+		return $this->getConnection( DB_MASTER, array() );
+	}
+
+	/**
+	 * Releases the lease on the given database connection. This is useful mainly
+	 * for connections to a foreign wiki. It does nothing for connections to the local wiki.
+	 *
+	 * @see LoadBalancer::reuseConnection
+	 *
+	 * @param DatabaseBase $db the database
+	 *
+	 * @since 1.20
+	 */
+	public function releaseConnection( DatabaseBase $db ) {
+		parent::releaseConnection( $db ); // just make it public
+	}
+
+	/**
 	 * Update the records matching the provided conditions by
 	 * setting the fields that are keys in the $values param to
 	 * their corresponding values.
@@ -431,14 +655,17 @@ abstract class ORMTable implements IORMTable {
 	 * @return boolean Success indicator
 	 */
 	public function update( array $values, array $conditions = array() ) {
-		$dbw = wfGetDB( DB_MASTER );
+		$dbw = $this->getWriteDbConnection();
 
-		return $dbw->update(
+		$result = $dbw->update(
 			$this->getName(),
 			$this->getPrefixedValues( $values ),
 			$this->getPrefixedValues( $conditions ),
 			__METHOD__
 		) !== false; // DatabaseBase::update does not always return true for success as documented...
+
+		$this->releaseConnection( $dbw );
+		return $result;
 	}
 
 	/**
@@ -450,6 +677,7 @@ abstract class ORMTable implements IORMTable {
 	 * @param array $conditions
 	 */
 	public function updateSummaryFields( $summaryFields = null, array $conditions = array() ) {
+		$slave = $this->getReadDb();
 		$this->setReadDb( DB_MASTER );
 
 		/**
@@ -461,7 +689,7 @@ abstract class ORMTable implements IORMTable {
 			$item->save();
 		}
 
-		$this->setReadDb( DB_SLAVE );
+		$this->setReadDb( $slave );
 	}
 
 	/**
@@ -559,6 +787,7 @@ abstract class ORMTable implements IORMTable {
 	 * Get an instance of this class.
 	 *
 	 * @since 1.20
+	 * @deprecated since 1.21
 	 *
 	 * @return IORMTable
 	 */