[Pkg-xfce-devel] Bug#733261: Bug#733261: lightdm lost ability not to set LANG

[Martin Dickopp]

On Sat, Dec 28, 2013 at 11:45:30PM +0100, Yves-Alexis Perez wrote:
> On Fri, Dec 27, 2013 at 10:38:33PM +0100, Martin Dickopp wrote:
> > Package: lightdm
> > Version: 1.8.5-2
> > Severity: normal
> > 
> > Hello,
> > 
> > It seems that LightDM lost the ability not to set the LANG environment
> > variable with the 1.6.3-1 -> 1.8.5-2 upgrade.
> > 
> > My system is configured as follows:
> > 
> > $ cat /etc/default/locale
> > LC_CTYPE=C.UTF-8
> > $ grep -v ^# /etc/locale.gen
> > 
> > de_DE ISO-8859-1
> > de_DE.UTF-8 UTF-8
> > en_US ISO-8859-1
> > en_US.UTF-8 UTF-8
> > 
> > I have disabled the language selector in
> > /etc/lightdm/lightdm-gtk-greeter.conf (show-language-selector=false).
> > 
> > Observed behavior: After logging in, the LANG environment variable is set
> > to "de_DE.utf8", which appears to be based on one of the entries (maybe
> > the first) in /etc/locale.gen.
> > 
> > Expected behavior: LANG unset, or set to something neutral like "C" or
> > "POSIX".
> 
> Do you have a .dmrc? Can you paste the content?

$ cat ~/.dmrc

[Desktop]
Session=lightdm-xsession
Language=de_DE.utf8

If I remove the file and restart lightdm, it is recreated with the same
content. After some experimentation, I found that lightdm keeps another
copy of the file in /var/cache/lightdm/dmrc. Removing both ~/.dmrc and
/var/cache/lightdm/dmrc/martin.dmrc resolves the issue!

While my immediate issue is resolved, I still find this behavior
unfortunate for three reasons:

- Recreating a file a user has deleted from a shadow copy is probably as
  surprising to many users as it has been to me. :-)

- While I'm also "root" on the machine in question, most users don't have
  write permission in /var/cache/lightdm/dmrc.

- According to my understanding, programs must handle files stored under
  /var/cache going away (e.g. /var/cache can be omitted from backups).
  It's therefore surprising that removal of a file under /var/cache
  changes the behavior.

Thanks,
Martin