control: tag - unreproducible
Hello,
after getting no answers I've studied how to debug XFCE 4.
I'm adding new and more useful debug information to help fixing the
problem and also explain why you can't reproduce it.
Apparently the source of the bug is unallocated memory (a NULL pointer,
0x0..0 in gdb) and there are also signs of an incompatibility with the
signal management of a specific version of GLib 2:
> (xfce4-panel:1964): GLib-GObject-WARNING **:
> /build/glib2.0-B1uXKV/glib2.0-2.50.3/./gobject/gsignal.c:3492: signal
> name 'selection_changed' is invalid for instance '0x55b07a0221c0' of
> type 'GailMenuItem'
> (xfce4-panel:1964): libtasklist-CRITICAL **: tasklist-widget.c:1777
> (xfce_tasklist_window_removed): expression 'n == 5' failed.
> (xfce4-panel:1603): libtasklist-CRITICAL **: tasklist-widget.c:2681
> (xfce_tasklist_button_enter_notify_event): expression
> 'XFCE_IS_TASKLIST (child->tasklist)' failed.
> (xfce4-panel:1603): libtasklist-CRITICAL **: tasklist-widget.c:2805
> (xfce_tasklist_button_enter_notify_event_disconnected): expression
> 'WNCK_IS_WINDOW (child->window)' failed.
> (xfce4-panel:1603): libtasklist-CRITICAL **: tasklist-widget.c:1871
> (xfce_tasklist_update_icon_geometries): expression 'WNCK_IS_WINDOW
> (child->window)' failed.
> (xfce4-panel:1603): libtasklist-CRITICAL **: tasklist-widget.c:2883
> (xfce_tasklist_button_activate): expression 'WNCK_IS_WINDOW
> (child->window)' failed.
> (xfce4-panel:1603): GLib-GObject-WARNING **: instance with invalid
> (NULL) class pointer
> (xfce4-panel:1603): GLib-GObject-CRITICAL **:
> g_signal_handlers_disconnect_matched: assertion 'G_TYPE_CHECK_INSTANCE
> (instance)' failed
In my opinion the bug could be traced to a single value:
'tasklist-widget.c' is trying to access the wrong object of a collection
and this is caused by the incorrect handling of signals in 'gsignal.c',
that can be the root cause of the problem.
I've attached 2 log files, the 1st with PANEL_DEBUG=gdb and the 2nd with
PANEL_DEBUG=tasklist, so you have all debugging information plus the
correct library versions to reproduce it.
Regards,
Lorenzo
xfce4-panel(main): version 4.12.1 on gtk+ 2.24.31 (2.24.31), glib 2.50.3 (2.50.2)
xfce4-panel(main): running external plugins with /usr/bin/gdb, logs stored in /tmp
xfce4-panel(module-factory): reading /usr/share/xfce4/panel/plugins
xfce4-panel(module-factory): reading /usr/share/xfce4/panel-plugins
xfce4-panel(application): found window manager after 1 tries
xfce4-panel(base-window): 0x55b079ed60c0: rgba colormap=0x55b079ee52d0, compositing=true
xfce4-panel(base-window): 0x55b079ed60c0: rgba colormap=0x55b079ee52d0, compositing=true
xfce4-panel(display-layout): 0x55b079ed60c0: display=:0.0{comp=true}, screen-0[0x55b079e84b30]=[1366,768] (monitor-0=[0,0;1366,768])
xfce4-panel(positioning): 0x55b079ed60c0: screen=0x55b079e84b30, monitors=1, output-name=(null), span-monitors=false, base=683,746
xfce4-panel(positioning): 0x55b079ed60c0: working-area: screen=0x55b079e84b30, x=0, y=0, w=1366, h=768
xfce4-panel(struts): 0x55b079ed60c0: bottom=41, start_x=0, end_x=1365
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/2
xfce4-panel(module): new item (type=external-wrapper, name=whiskermenu, id=2)
xfce4-panel(external): whiskermenu-2: child spawned; pid=1965, argc=25
xfce4-panel(module): new item (type=object-type, name=separator, id=9)
xfce4-panel(module): new item (type=object-type, name=tasklist, id=6)
xfce4-panel(module): new item (type=object-type, name=separator, id=10)
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/11
xfce4-panel(module): new item (type=external-wrapper, name=pulseaudio, id=11)
xfce4-panel(external): pulseaudio-11: child spawned; pid=1968, argc=25
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/4
xfce4-panel(module): new item (type=external-wrapper, name=systray, id=4)
xfce4-panel(external): systray-4: child spawned; pid=1969, argc=25
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/13
xfce4-panel(module): new item (type=external-wrapper, name=datetime, id=13)
xfce4-panel(external): datetime-13: child spawned; pid=1971, argc=25
xfce4-panel(base-window): 0x55b079ed6350: rgba colormap=0x55b079ee52d0, compositing=true
xfce4-panel(base-window): 0x55b079ed6350: rgba colormap=0x55b079ee52d0, compositing=true
xfce4-panel(base-window): 0x55b079f63050: rgba colormap=0x55b079ee52d0, compositing=true
xfce4-panel(display-layout): 0x55b079ed6350: display=:0.0{comp=true}, screen-0[0x55b079e84b30]=[1366,768] (monitor-0=[0,0;1366,768])
xfce4-panel(positioning): 0x55b079ed6350: screen=0x55b079e84b30, monitors=1, output-name=(null), span-monitors=false, base=683,25
xfce4-panel(positioning): 0x55b079ed6350: working-area: screen=0x55b079e84b30, x=0, y=0, w=1366, h=768
xfce4-panel(base-window): 0x55b079ed65e0: rgba colormap=0x55b079ee52d0, compositing=true
xfce4-panel(base-window): 0x55b079ed65e0: rgba colormap=0x55b079ee52d0, compositing=true
