Critical warnings when closing active window and "control active windows" is used
(wrapper-2.0:73000): GLib-GObject-CRITICAL **: 13:27:44.406: instance with invalid (NULL) class pointer
(wrapper-2.0:73000): GLib-GObject-CRITICAL **: 13:27:44.406: g_signal_handler_is_connected: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
Core was generated by `/opt/lib/xfce4/panel/wrapper-2.0.orig /opt/lib/xfce4/panel/plugins/libwckmenu.s'.
Program terminated with signal SIGTRAP, Trace/breakpoint trap.
#0 g_logv (log_domain=0x77393d632015 "GLib-GObject", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, args=args@entry=0x7ffc6a8c53e0) at ../glib/glib/gmessages.c:1277
1277 g_private_set (&g_log_depth, GUINT_TO_POINTER (depth));
[Current thread is 1 (Thread 0x77393b121e80 (LWP 144314))]
(gdb) bt
#0 g_logv (log_domain=0x77393d632015 "GLib-GObject", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, args=args@entry=0x7ffc6a8c53e0) at ../glib/glib/gmessages.c:1277
#1 0x000077393cb2e754 in g_log
(log_domain=log_domain@entry=0x77393d632015 "GLib-GObject", log_level=log_level@entry=G_LOG_LEVEL_CRITICAL, format=format@entry=0x77393d63a8d8 "instance with invalid (NULL) class pointer")
at ../glib/glib/gmessages.c:1315
#2 0x000077393d6295eb in g_type_check_instance (type_instance=<optimized out>) at ../glib/gobject/gtype.c:4268
#3 0x000077393d61adaa in g_signal_handler_is_connected (instance=instance@entry=0x5d229ab46be0, handler_id=2239) at ../glib/gobject/gsignal.c:2704
#4 0x000077393d816868 in wck_signal_handler_disconnect (object=object@entry=0x5d229ab46be0, handler=2239) at wck-utils.c:45
#5 0x000077393d8158ef in on_control_window_changed (controlwindow=0x5d229a9fe120 [WnckWindow], previous=0x5d229ab46be0, data=0x5d229a9c9da0) at wckmenu-icon.c:183
#6 0x000077393d816cc3 in active_window_changed (screen=<optimized out>, previous=previous@entry=0x0, win=0x5d229a8fa3d0) at wck-utils.c:236
#11 0x000077393d621a94 in <emit signal 'active-window-changed' on instance 0x5d229a948040 [WnckScreen]> (instance=<optimized out>, signal_id=signal_id@entry=260, detail=detail@entry=0)
at ../glib/gobject/gsignal.c:3583
#7 0x000077393d600156 in g_cclosure_marshal_VOID__OBJECTv
(closure=0x5d229a931420, return_value=<optimized out>, instance=0x5d229a948040, args=<optimized out>, marshal_data=<optimized out>, n_params=<optimized out>, param_types=0x5d229a8fa800)
at ../glib/gobject/gmarshal.c:1910
#8 0x000077393d6218d3 in _g_closure_invoke_va (param_types=0x5d229a8fa800, n_params=<optimized out>, args=0x7ffc6a8c5810, instance=0x5d229a948040, return_value=0x0, closure=0x5d229a931420)
at ../glib/gobject/gclosure.c:897
#9 signal_emit_valist_unlocked (instance=instance@entry=0x5d229a948040, signal_id=signal_id@entry=260, detail=detail@entry=0, var_args=var_args@entry=0x7ffc6a8c5810) at ../glib/gobject/gsignal.c:3424
#10 0x000077393d6219d7 in g_signal_emit_valist (instance=0x5d229a948040, signal_id=260, detail=0, var_args=var_args@entry=0x7ffc6a8c5810) at ../glib/gobject/gsignal.c:3263
#12 0x000077393c326eb9 in emit_active_window_changed (screen=0x5d229a948040 [WnckScreen]) at ../libwnck/libwnck/screen.c:2183
#13 update_active_window (screen=0x5d229a948040 [WnckScreen]) at ../libwnck/libwnck/screen.c:1903
#14 do_update_now (screen=0x5d229a948040 [WnckScreen]) at ../libwnck/libwnck/screen.c:2138
#15 0x000077393c329888 in update_idle (data=<optimized out>) at ../libwnck/libwnck/screen.c:2156
#16 0x000077393cb29199 in g_main_dispatch (context=0x5d229a780380) at ../glib/glib/gmain.c:3344
#17 0x000077393cb883bf in g_main_context_dispatch_unlocked (context=0x5d229a780380) at ../glib/glib/gmain.c:4152
#18 g_main_context_iterate_unlocked.isra.0 (context=0x5d229a780380, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:4217
#19 0x000077393cb29dc7 in g_main_loop_run (loop=0x5d229a9bf010) at ../glib/glib/gmain.c:4419
#20 0x000077393cfed2bf in gtk_main () at ../gtk/gtk/gtkmain.c:1329
#21 0x00005d22997c913c in main (argc=<optimized out>, argv=<optimized out>) at main.c:376version: git master 5905e78f