Comment 2 for bug 943801

StacktraceTop:
 g_type_check_instance_is_a (type_instance=<optimized out>, iface_type=<optimized out>) at /build/buildd/glib2.0-2.31.18/./gobject/gtype.c:3965
 gdk_window_get_screen (window=0x7fffd09c2f88) at /build/buildd/gtk+3.0-3.3.16/./gdk/gdkwindow.c:2201
 gdk_device_get_position (device=0x174e8a0, screen=0x7fffd09c2f80, x=0x7fffd09c2f88, y=0x7fffd09c2f8c) at /build/buildd/gtk+3.0-3.3.16/./gdk/gdkdevice.c:453
 gtk_menu_position (menu=0x1b046e0, set_scroll_offset=1) at /build/buildd/gtk+3.0-3.3.16/./gtk/gtkmenu.c:4627
 gtk_menu_popup_for_device (menu=<optimized out>, device=<optimized out>, parent_menu_shell=0x0, parent_menu_item=0x0, func=0, data=0x0, destroy=0, button=3, activate_time=1464937) at /build/buildd/gtk+3.0-3.3.16/./gtk/gtkmenu.c:1645