gnome-control-center removes XKBMODEL and XKBOPTIONS from /etc/default/keyboard

[Andreas Henriksson]

Hello again.

On Fri, Feb 19, 2016 at 01:25:00PM -0300, Felipe Sateler wrote:
> On 19 February 2016 at 13:10, Andreas Henriksson <andreas at fatal.se> wrote:
[...]
> >> 1. $ grep -q XKBMODEL /etc/default/keyboard && echo fine || echo broken
> >>    -> fine
> >> 2. $ gnome-control-center
> >> 3. Go to "Region & Language"
> >> 4. Go to "Login Screen"
> >> 5. In the "Input Sources" section add some random keyboard layout
> >> 6. $ grep -q XKBMODEL /etc/default/keyboard && echo fine || echo broken
> >>    -> broken
> >>
> >> The test is done on a regular Jessie system.  The version of gnome-control-center
> >> is 1:3.14.2-3.
> >
> > Thanks for the testcase. The gnome-control-center program only calls out to
> > "localed" via dbus. In Debian it is patched with the following patch:
> >
> > http://sources.debian.net/src/systemd/215-17%2Bdeb8u3/debian/patches/Update-localed-to-use-the-Debian-config-files.patch/#L114
> >
> > (And as you can see on that particular line XKBMODEL is parsed. Not sure
> > what resets it.)
> 
> Line 178 does when it is empty:
> 
> http://sources.debian.net/src/systemd/215-17%2Bdeb8u3/debian/patches/Update-localed-to-use-the-Debian-config-files.patch/#L177
> 
> Not sure why though.

See also:
http://sources.debian.net/src/gnome-control-center/1:3.18.2-1/panels/region/cc-region-panel.c/#L1686

cf. https://www.freedesktop.org/wiki/Software/systemd/localed/

Eg. g-c-c always sends model and layout as empty strings, which is the reason
patched localed resets them....

Now is there some kind of specification on the "proper" formatting
of /etc/default/keyboard somewhere?
Which fields are required to be included in the file (even when their
value is empty)?

Regards,
Andreas Henriksson