Comment 2 for bug 754123

StacktraceTop:
 ?? ()
 closure_invoke_notifiers (closure=0x2000000, return_value=0x0, n_param_values=4, param_values=0x29c3d80, invocation_hint=0x7fffe81ec500) at /build/buildd/glib2.0-2.28.5/./gobject/gclosure.c:289
 g_closure_invoke (closure=0x2000000, return_value=0x0, n_param_values=4, param_values=0x29c3d80, invocation_hint=0x7fffe81ec500) at /build/buildd/glib2.0-2.28.5/./gobject/gclosure.c:773
 signal_emit_unlocked_R (node=<value optimized out>, detail=0, instance=0x1927d80, emission_return=0x0, instance_and_params=0x29c3d80) at /build/buildd/glib2.0-2.28.5/./gobject/gsignal.c:3252
 g_signal_emit_valist (instance=<value optimized out>, signal_id=<value optimized out>, detail=<value optimized out>, var_args=<value optimized out>) at /build/buildd/glib2.0-2.28.5/./gobject/gsignal.c:2983