gnome-panel hangs when using recently used files

[Nicolas da Luz Duque]

Binary package hint: gnome-panel

Steps to reproduce:
1) Right-click on an application launcher in the gnome-panel, and select "properties".
2) Click on the icon in the properties menu, in order to change the icon of the launcher.
3) In this menu, click on "Browse..." right to the URI bar.
4) Now click on "recently used".

Expected result:
You are presented with a list of recently used files to use as new icons for the launcher.

Actual result:
gnome-panel hangs and has to be killed manually.

ProblemType: Bug
Architecture: i386
Date: Sat Dec 19 11:57:37 2009
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
NonfreeKernelModules: nvidia
Package: gnome-panel 1:2.28.0-0ubuntu6
ProcEnviron:
 LANG=fr_BE.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-16.53-generic
SourcePackage: gnome-panel
Uname: Linux 2.6.31-16-generic i686

[Chris Coulson (chrisccoulson)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please try to obtain a backtrace following the instructions at http://wiki.ubuntu.com/DebuggingProgramCrash and upload the backtrace (as an attachment) to the bug report. This will greatly help us in tracking down your problem.

[Nicolas da Luz Duque (hot-boy)]

I'm willing to do that, but like I said, the program doesn't crash, and seems to enter an endless loop.

What should I do, then? Enter the loop, then ctrl+c in gdb and get the trace then?

How can I prevent gnome-panel from respawning on its own to be able to run it in gdb? It used to be possible to remove the "auto-respawn" in gnome-session-properties, but it's not there anymore...

[Chris Coulson (chrisccoulson)]

Yes, you can press CTRL+C in GDB to interrupt it and get a backtrace that way. It might be worth interrupting a couple of times to make sure that it interrupts in a similar code section.

You can attach GDB to the already running instance of gnome-panel, rather than killing the existing one and starting a new process.

[Nicolas da Luz Duque (hot-boy)]

That doesn't seem to work... I've attached the running gnome-panel in gdb as described in https://wiki.ubuntu.com/Backtrace , but when I ctrl+c in order to interrupt the process, it seems to work (in that the cursor stops changing when hovering above the file selection window) but I don't get the (gdb) prompt back so I can't ask it for a backtrace.

That's how it looks like:
<blabla debuging symbols>
(gdb) continue
Continuing.
<here I make it hang>
^C
<nothing more>

I'm sorry, but the extent of my gdb experience so far is launching programs in it, making them crash, then getting the backtrace. I've never interrupted a process before to get a trace. As you said, since it seems to enter an infinite loop, the trace we'll get might not even be relevant at all.

Wouldn't it be easier for a dev to reproduce this bug and investigate it himself? If you insist on me doing it, maybe you can guide me through the steps on irc or something. I'm "iceman" on #ubuntu-bugs.

[Pedro Villavicencio (pedro)]

There's no thing on the info you attached, may you please try again? Thanks.