gnome-control-center crashes if you change the language of the login screen

[Marius Gedminas]

Steps to reproduce:
1. Launch gnome-control-center
2. Select 'Region & Language'
3. Click on the 'Login Screen' button
4. Click on Language, type admin password as required
5. Change the language to something else, click Done

What happens:
gnome-control-center crashes (bug 1236612 according to Apport, but it seems to be private).

What should happen:
no crash.

Extra details:
Running gnome-control-center undel Valgrind pinpoints the error to on_localed_properties_changed (cc-region-panel.c:1538), which does g_free (lang);

If you look at ./debian/patches/52_region_language.patch, you'll see that it introduces the g_free (lang) bit. It needs to do that because it adds a strip_quotes() call to the original assignment of lang. However there's a second assignment to lang, in the middle of the patch context:

                 if (!lang) {
                         lang = "";
                 }

Changing this to lang = g_strdup ("") should be enough to fix the bug.

I'm using Ubuntu GNOME, and gnome-control-center comes from the gnome3-team/gnome3 PPA. This bug does not appear to affect the stock Ubuntu version because upstream 3.6.3 code did not have the lang = "" assignment.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: gnome-control-center 1:3.8.5-0ubuntu1~saucy1 [origin: LP-PPA-gnome3-team-gnome3]
Uname: Linux 3.12.0-031200rc1-generic x86_64
ApportVersion: 2.12.5-0ubuntu2
Architecture: amd64
Date: Tue Oct 22 19:08:37 2013
EcryptfsInUse: Yes
InstallationDate: Installed on 2012-07-25 (454 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to saucy on 2013-10-17 (5 days ago)
usr_lib_gnome-control-center: deja-dup 27.3.1-0ubuntu1

[Marius Gedminas (mgedmin)]

Workaround:

    localectl set-locale LANG=en_US.UTF-8

(or whichever language you prefer for the login screen).

[Forage (forage)]

The change should fix bug #1241978

[Marius Gedminas (mgedmin)]

Bug 1236612 is no longer private, and while the error looks similar ("munmap_chunk(): invalid pointer"), it is unrelated.

[Tim Lunn (darkxst)]

we had already fixed this in the 3.10 package, but forgot to backport to 3.8 also.

Done now.