$out = " <revision>\n";
$out .= " " . Xml::element( 'id', null, strval( $row->rev_id ) ) . "\n";
+ if( $row->rev_parent_id ) {
+ $out .= " " . Xml::element( 'parentid', null, strval( $row->rev_parent_id ) ) . "\n";
+ }
$out .= $this->writeTimestamp( $row->rev_timestamp );