Node ID arguments with no results return all menu items

When using the Node id argument and passing in the nid of the active node via a default argument, if the node isn't in a menu, the view just displays everything that is in a menu.

I'm filing this as a support request instead of a bug because I'm not sure if this is the intended behavior. It is arising in menu_node_views_arguments_nid.inc in query(). If there's no $pid, I don't think anything should be returned, but right now the code skips over adding any limiting WHERE clause. There's probably a better way to manage that than what's below, but it does the trick.

    else {
      $where = "1 = 0";
      $this->query->add_where(0, $where);
    }

The use case here is a block that displays all the menu items 1 level below the active node. If there's a better way to achieve that instead of the nid argument and default values, maybe this isn't needed.

Sorry for not attaching a proper patch at the moment. If this is determined to be a bug, I will.