+ $newRel = Parser::getExternalLinkRel( $url, $title );
+ if ( !isset( $attribs['rel'] ) || $attribs['rel'] === '' ) {
+ $attribs['rel'] = $newRel;
+ } elseif( $newRel !== '' ) {
+ // Merge the rel attributes.
+ $newRels = explode( ' ', $newRel );
+ $oldRels = explode( ' ', $attribs['rel'] );
+ $combined = array_unique( array_merge( $newRels, $oldRels ) );
+ $attribs['rel'] = implode( ' ', $combined );
+ }