Workspace switcher no longer works after adding 17th workspace

[Shawn McKenney]

Binary package hint: gnome-panel

After adding the 17th workspace from the workspace switcher, switching to any workspace triggers a switch to workspace 1. gnome-session seems to go into some sort of tight loop. Logging out and removing ~/.gconf* resets the workspaces and the switcher works as expected. The problem can be reproduced by adding the 17th workspace again.

All of the visual effects are turned off.
I am using the nvidia driver 195.36.15.

I'm not sure what other information would be pertinent but I'll be happy to help diagnose the problem if pointed in the right direction.

$ lsb_release -rd
Description: Ubuntu lucid (development branch)
Release: 10.04

$ nvidia-settings
gnome-panel:
  Installed: 1:2.29.92.1-0ubuntu3
  Candidate: 1:2.29.92.1-0ubuntu3

Thanks,
Shawn

ProblemType: Bug
Architecture: amd64
Date: Tue Mar 23 20:19:50 2010
DistroRelease: Ubuntu 10.04
NonfreeKernelModules: nvidia
Package: gnome-panel 1:2.29.92.1-0ubuntu3
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-17.26-generic 2.6.32.10+drm33.1
SourcePackage: gnome-panel
Uname: Linux 2.6.32-17-generic x86_64

[Shawn McKenney (shawn-mckenney)]

A little more information -

The window manager is metacity. I can go into gconf-editor and change the number of workspaces there. The same result occurs. When the number of workspaces is set above 16, nothing seems to occur at that point (when num_workspaces is actually changed). However, when I try to change workspaces, metacity dies (window frames disappear and all of the windows move to workspace 1). gconfd-2 starts to hammer the hard drive. By observing top, I can see that metacity is continually being restarted. As soon as I right click on num_workspaces and "Unset Key", num_workspaces returns to 4 and everyone is happy again...

[Shawn McKenney (shawn-mckenney)]

I figured out the source of this problem:

I installed the metacity source (apt-get source metacity), built it with debugging and replaced the running metacity:

./src/metacity --replace

After increasing the number of workspaces to 17 and attempting to change workspaces, metacity asserted an error at:

./metacity-2.28.1/src/core/prefs.c:2486:meta_prefs_get_workspace_name: assertion failed: (workspace_names[i] != NULL)

It looks like ./metacity-2.28.1/src/metacity.schemas only creates 16 workspace name keys in the gconf database. When more than 16 workspaces are created using the Workspace Switcher Preferences applet, the new keys are not created. However, once >16 workspaces are selected and then the workspace name is changed on any of the workspaces, all of the keys are created in the gconf database. gconf-editor still complains that "This key has ho schema" for all workspaces >16, but this doesn't seem to be a problem.

[Pedro Villavicencio (pedro)]

Thanks for the bug report. This particular bug has already been reported into our bug tracking system, but please feel free to report any further bugs you find.