Comment 2 for bug 809865

StacktraceTop:
 g_closure_invoke (closure=0x17d0f40, return_value=0x0, n_param_values=2, param_values=0x683ff60, invocation_hint=0x7fff52cc2140) at /build/buildd/glib2.0-2.29.10/./gobject/gclosure.c:751
 signal_emit_unlocked_R (node=<value optimized out>, detail=0, instance=0x1bb2010, emission_return=0x0, instance_and_params=0x683ff60) at /build/buildd/glib2.0-2.29.10/./gobject/gsignal.c:3186
 g_signal_emit_valist (instance=<value optimized out>, signal_id=<value optimized out>, detail=<value optimized out>, var_args=0x7fff52cc2328) at /build/buildd/glib2.0-2.29.10/./gobject/gsignal.c:2987
 g_signal_emit (instance=<value optimized out>, signal_id=<value optimized out>, detail=<value optimized out>) at /build/buildd/glib2.0-2.29.10/./gobject/gsignal.c:3044
 gtk_grab_notify_foreach (child=0x1bb2010, data=0x7fff52cc25e0) at /build/buildd/gtk+3.0-3.1.8/./gtk/gtkmain.c:2098