Comment # 24 on bug 567324 from Dr. Werner Fink

(In reply to Carlos Robinson from comment #23)

I'm in doubt that "/etc/profile.d/lang.sh" is sourced by your login shell or by
the shell used by the display manager.  IMHO the scripts/setup used by your
used display manager simply ignore the scripts below /etc/X11/xdm/.

This bug has been resolved correctly and it is/was confirmed that the fix
works.
Please add two lines

  tmp=$(mktemp /tmp/lang.sh.XXXXXX) && echo $(date): lang.sh ${1+"$@"} > $tmp

at the very begin of "/etc/profile.d/lang.sh" and retry.  It there is no file

  /tmp/lang.sh.*

after your login then close this bug and open a new one against XFCE.

Btw: "/etc/profile.d/lang.sh"  is a file which has to be sourced by the bash
and not executed. That is that the builtin command "return" simply stops the
bash on sourcing/reading the file at this point:

  /suse/werner> cat test.sh
  echo Before
  test -z "$GDM_LANG" || return
  echo After
  /suse/werner> bash -c '. test.sh'
  Before
  After
  /suse/werner> bash -c 'export GDM_LANG=de ; . test.sh'
  Before
  /suse/werner>