+ } elseif( $retval === null ) {
+ if ( $closure ) {
+ $prettyFunc = "$event closure";
+ } elseif( is_array( $callback ) ) {
+ if( is_object( $callback[0] ) ) {
+ $prettyClass = get_class( $callback[0] );
+ } else {
+ $prettyClass = strval( $callback[0] );
+ }
+ $prettyFunc = $prettyClass . '::' . strval( $callback[1] );
+ } else {
+ $prettyFunc = strval( $callback );
+ }
+ throw new MWException( "Detected bug in an extension! " .
+ "Hook $prettyFunc failed to return a value; " .
+ "should return true to continue hook processing or false to abort." );
+ } else if ( !$retval ) {