Comment 32 for bug 1198471

The warning is raised for the following chunk of code in lib/unity-gtk-action-group.c:1030:

/**
 * unity_gtk_action_group_disconnect_shell:
 * @group: a #UnityGtkActionGroup.
 * @shell: a #UnityGtkMenuShell.
 *
 * Removes the actions for @shell from @group.
 */
void
unity_gtk_action_group_disconnect_shell (UnityGtkActionGroup *group,
                                         UnityGtkMenuShell *shell)
{
  UnityGtkActionGroup *action_group;
  GSequence *visible_indices;

  g_return_if_fail (UNITY_GTK_IS_ACTION_GROUP (group));
  g_return_if_fail (UNITY_GTK_IS_MENU_SHELL (shell));
  g_warn_if_fail (shell->action_group == group);

  visible_indices = shell->visible_indices;

----

Specifically the line:

  g_warn_if_fail (shell->action_group == group);

I think that could be raised by handling the data like { "(null)" }, parent) in unity_gtk_menu_shell_handle_item_notify. Because the data is null, but I am still digging in the source code