Unlock window doesn't show; gnome-screensaver-dialog crashes

[Jeremy Nickurak]

Binary package hint: gnome-screensaver

Issue: Gnome-screensaver-dialog doesn't appear

Moving the mouse or typing when the screen is locked shows me the mouse cursor momentarily, then disappears again, without ever showing the password dialog.

Attempting to run gnome-screensaver-dialog directly results in:

The program 'gnome-screensaver-dialog' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadClass, invalid event class'.
  (Details: serial 269 error_code 172 request_code 148 minor_code 6)
  (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.)

Program exited with code 01.

I'm running gnome-screensaver 2.24.0-0ubuntu6 on jaunty.

I rebuilt the gnome-screensaver with debugging symbols, and ran:

gdb --args gnome-screensaver-daemon --sync

with "break gdk_x_error" as suggested produces the following backtrace:

#1 0x00007fd68e5d8861 in xkl_process_error () from /usr/lib/libxklavier.so.12
#2 0x00007fd68d1045b4 in _XError () from /usr/lib/libX11.so.6
#3 0x00007fd68d10b8f9 in ?? () from /usr/lib/libX11.so.6
#4 0x00007fd68d10bfd8 in _XReply () from /usr/lib/libX11.so.6
#5 0x00007fd68d0ffe13 in XSync () from /usr/lib/libX11.so.6
#6 0x00007fd68d0fffcb in ?? () from /usr/lib/libX11.so.6
#7 0x00007fd6891657d8 in XSelectExtensionEvent () from /usr/lib/libXi.so.6
#8 0x00007fd68e5dc646 in xkl_xkb_resume_listen () from /usr/lib/libxklavier.so.12
#9 0x00007fd68e5d865f in xkl_engine_resume_listen () from /usr/lib/libxklavier.so.12
#10 0x00007fd68e5d86c1 in xkl_engine_start_listen () from /usr/lib/libxklavier.so.12
#11 0x00007fd68ec376b8 in ?? () from /usr/lib/libgnomekbdui.so.3
#12 0x00007fd68a694e15 in g_type_create_instance () from /usr/lib/libgobject-2.0.so.0
#13 0x00007fd68a6795bb in ?? () from /usr/lib/libgobject-2.0.so.0
#14 0x00007fd68a679c03 in g_object_newv () from /usr/lib/libgobject-2.0.so.0
#15 0x00007fd68a67a747 in g_object_new_valist () from /usr/lib/libgobject-2.0.so.0
#16 0x00007fd68a67a88c in g_object_new () from /usr/lib/libgobject-2.0.so.0
#17 0x00007fd68ec36faa in gkbd_indicator_new () from /usr/lib/libgnomekbdui.so.3
#18 0x000000000040b27b in gs_lock_plug_init (plug=0xffc010) at gs-lock-plug.c:1806
#19 0x00007fd68a694e15 in g_type_create_instance () from /usr/lib/libgobject-2.0.so.0
#20 0x00007fd68a6795bb in ?? () from /usr/lib/libgobject-2.0.so.0
#21 0x00007fd68a679c03 in g_object_newv () from /usr/lib/libgobject-2.0.so.0
#22 0x00007fd68a67a747 in g_object_new_valist () from /usr/lib/libgobject-2.0.so.0
#23 0x00007fd68a67a88c in g_object_new () from /usr/lib/libgobject-2.0.so.0
#24 0x00000000004085a2 in gs_lock_plug_new () at gs-lock-plug.c:1941
#25 0x00000000004077b6 in popup_dialog_idle () at gnome-screensaver-dialog.c:368
#26 0x00007fd68a3dc20a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#27 0x00007fd68a3df8e0 in ?? () from /usr/lib/libglib-2.0.so.0
#28 0x00007fd68a3dfdad in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#29 0x00007fd68cbfbbc7 in IA__gtk_main () at /build/buildd/gtk+2.0-2.16.1/gtk/gtkmain.c:1205
#30 0x0000000000407756 in main (argc=1, argv=0x7fff9870ab98) at gnome-screensaver-dialog.c:576

This was working fine on the machine a couple of weeks ago, but there was a power outage. Ever since the machine rebooted, locked sessions are impossible to unlock without logging in on a terminal and manually killing gnome-screensaver.

[Jens Maus (jens.maus)]

Let me add that I see the very same problem here with our SunRay Server System which we have running under Ubuntu 9.04 (Jaunty). Since we have installed updates and rebooted all SunRay sessions can't be locked anymore. After some short investigation we see that "gnome-screensaver" isn't automatically started anymore. And upon manually starting it and invoking the screensaver we can't unlock the screen anymore because there appears no dialog.

When manually starting the dialog we also received the following X error:

-- cut here --
The program 'gnome-screensaver-dialog' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadClass, invalid event class'.
  (Details: serial 269 error_code 133 request_code 131 minor_code 6)
  (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.)
-- cut here --

However, when logging into the system via a remote X connection rather than using the local SunRay displays gnome-screensaver comes up find and alslo gnome-screensaver-dialog works as expected.

So there seems to be really a problem with gnome-screensaver lately.

[Chris Coulson (chrisccoulson)]

Thank you for your bug report. This bug has already been reported, but please feel free to report any other bugs you find.