wikimedia / mediawiki

		global $wgDBname;

		// Allow for no old prefix

		if ( $this->getOption( 'old', 0 ) === '0' ) {

			$old = '';

		} else {

			// Use nice safe, sane, prefixes

			preg_match( '/^[a-zA-Z]+_$/', $this->getOption( 'old' ), $m );

			$old = isset( $m[0] ) ? $m[0] : false;

		}

		// Allow for no new prefix

		if ( $this->getOption( 'new', 0 ) === '0' ) {

			$new = '';

			$old = isset( $m[0] ) ? $m[0] : false;

		}

		// Allow for no new prefix

		if ( $this->getOption( 'new', 0 ) === '0' ) {

			$new = '';

		} else {

			// Use nice safe, sane, prefixes

			preg_match( '/^[a-zA-Z]+_$/', $this->getOption( 'new' ), $m );

			$new = isset( $m[0] ) ? $m[0] : false;

		}

		if ( $old === false || $new === false ) {

			$this->error( "Invalid prefix!", true );