Index: includes/Parser.php
===================================================================
--- includes/Parser.php	(revision 34151)
+++ includes/Parser.php	(working copy)
@@ -2835,6 +2835,8 @@
 					}
 					$result = call_user_func_array( $callback, $allArgs );
 					$found = true;
+					$noparse = true;
+					$preprocessFlags = 0;
 
 					if ( is_array( $result ) ) {
 						if ( isset( $result[0] ) ) {
@@ -2848,6 +2850,10 @@
 					} else {
 						$text = $result;
 					}
+					if ( !$noparse ) {
+						$text = $this->preprocessToDom( $text, $preprocessFlags );
+						$isChildObj = true;
+					}
 				}
 			}
 			wfProfileOut( __METHOD__ . '-pfunc' );