Bug#1029557: debian-edu-config: Session exits on first login on roaming-workstation fails

[Petter Reinholdtsen <pere@hungry.com>]

[Nico Winkelsträter]
> When a user tries to log in at a romaing workstation for the very first time
> the login prompt disappears, stays on the empty default-background for a few
> seconds and the returns to lightdm with a brief black-screen.
>
> On the second try everything works as expected.

This is by design.  There was (and probably still is) no way to change
$HOME from the PAM subsystem when the login already was in progress.  To
work around this limitiation the user is logged logged out on the first
try, after the home directory is created and /etc/passwd is updated with
the new home location, to ensure the new home directory is used during
future logins.  The home directory is changed from
/skole/tjener/home0/testes/ to /home/testes/ in your case.

-- 
Happy hacking
Petter Reinholdtsen