more fixes from mutter

1) https://git.gnome.org/browse/mutter/commit/src/ui/ui.c?id=f1620abfad0caf85b5958e32736accb3fecef7f1
2) https://git.gnome.org/browse/mutter/commit/src/ui/ui.c?id=4e21d5d61010b0aa5ddc3acccd9598384c3e8f01