A bug when edit topic from group forum list

On the group discussion list page, if cliek "edit" to edit a topic, it will fail when save.  The cause is the group_guid is incorrect.

To fix it, in page "\mod\groups\views\default\forms\forums\edittopic.php", modify lien 24 from

$group_guid = get_input("group");


$group_guid = $vars['entity']->container_guid;

Topic content can be edited on topic page, but to edit topic title we have to click "edit" on discussion list page. Elgg 1.7.5 has this bug, not sure if Elgg 1.7.6 has fixed or not.