[Xfce 4.8] - Panels Are Unstable And Crash Frequently ?

[Andrzej]

On 02/13/2012 01:29 AM, Jesse Palser wrote:
>
> I successfully debugged Xfce Panels, but it won't crash when I do it?
> What do I do now?
>
> On a clean install fully updated xubuntu 11.10
> if I delete default bottom panel and add a new panel on bottom
> and try to add "Applications Menu" to new bottom panel
> the panel dies and disappears?

Jesse, how are you adding the plugin? Do you press "Add" button in the 
"Add New Items" window or are you dragging the plugin to the panel?



I've just got a crash when dragging a plugin to the panel (Ubuntu 
11.10). It happens spuriously - I had to try D&D several times before I 
could produce the crash.

When I use a --sync option the problem goes away, which likely indicates 
that the problem is somewhere deeper in the Gtk/Gdk/XCB stack.

I had a similar issue in the panel workspace switcher:
https://bugzilla.xfce.org/show_bug.cgi?id=8202

I wonder if that's due to a bug in some libraries underneath or we are 
doing something dodgy in D&D.

The error message left by the xfce4-panel:

The program 'xfce4-panel' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadWindow (invalid Window parameter)'.
   (Details: serial 6116 error_code 3 request_code 3 minor_code 0)
   (Note to programmers: normally, X errors are reported asynchronously;
    that is, you will receive the error a while after causing it.
    To debug your program, run it with the --sync command line
    option to change this behavior. You can then get a meaningful
    backtrace from your debugger if you break on the gdk_x_error() 
function.)

The stacktrace is probably useless without the --sync option but I've 
attached it below nevertheless:

(gdb) bt
#0  _XError (dpy=0x80a4400, rep=0x8269448) at ../../src/XlibInt.c:1550
#1  0xb75f893d in handle_error (dpy=0x80a4400, err=0x8269448, 
in_XReply=1) at ../../src/xcb_io.c:212
#2  0xb75f8997 in handle_response (dpy=0x80a4400, response=0x8269448, 
in_XReply=1) at ../../src/xcb_io.c:324
#3  0xb75f9850 in _XReply (dpy=0x80a4400, rep=0xbffff278, extra=0, 
discard=1) at ../../src/xcb_io.c:626
#4  0xb7a613bc in _gdk_x11_get_window_child_info (display=0x80b00b0, 
window=356, get_wm_state=0, win_has_wm_state=0x0,
     children=0xbffff3b8, nchildren=0xbffff3bc) at 
/build/buildd/gtk+2.0-2.24.6/gdk/x11/gdkasync.c:731
#5  0xb7a6ab65 in gdk_window_cache_new (screen=0x80b40c8) at 
/build/buildd/gtk+2.0-2.24.6/gdk/x11/gdkdnd-x11.c:566
#6  gdk_window_cache_get (screen=0x80b40c8) at 
/build/buildd/gtk+2.0-2.24.6/gdk/x11/gdkdnd-x11.c:660
#7  drag_context_find_window_cache (screen=0x80b40c8, context=0x815c1d0)
     at /build/buildd/gtk+2.0-2.24.6/gdk/x11/gdkdnd-x11.c:3353
#8  IA__gdk_drag_find_window_for_screen (context=0x815c1d0, 
drag_window=0x0, screen=0x80b40c8, x_root=90, y_root=782,
     dest_window=0xbffff420, protocol=0xbffff424) at 
/build/buildd/gtk+2.0-2.24.6/gdk/x11/gdkdnd-x11.c:3396
#9  0xb7d6e920 in gtk_drag_update_idle (data=0x824a780) at 
/build/buildd/gtk+2.0-2.24.6/gtk/gtkdnd.c:3994
#10 0xb7a2ff88 in gdk_threads_dispatch (data=0x8185890) at 
/build/buildd/gtk+2.0-2.24.6/gdk/gdk.c:512
#11 0xb7736110 in g_idle_dispatch (source=0x823fcb8, callback=0xb7a2ff20 
<gdk_threads_dispatch>, user_data=0x8185890)
     at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:4801
#12 0xb773a25f in g_main_dispatch (context=0x80ba7c8) at 
/build/buildd/glib2.0-2.30.0/./glib/gmain.c:2441
#13 g_main_context_dispatch (context=0x80ba7c8) at 
/build/buildd/glib2.0-2.30.0/./glib/gmain.c:3011
#14 0xb773a990 in g_main_context_iterate (context=0x80ba7c8, 
block=-1217096928, dispatch=1, self=<optimized out>)
     at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3089
#15 0xb773af9b in g_main_loop_run (loop=0x80d25a8) at 
/build/buildd/glib2.0-2.30.0/./glib/gmain.c:3297
#16 0xb7c0efcf in IA__gtk_main () at 
/build/buildd/gtk+2.0-2.24.6/gtk/gtkmain.c:1329
#17 0x0805419e in main (argc=1, argv=0xbffff724) at main.c:338

Andrzej