Comment 48 for bug 49594

Improvement: Simply add 2 lines to /etc/gdm/PostSession/Default and do _not_ store a backup of Default in the PostSession directory.

$ ls /etc/gdm/PostSession/
Default

$ tail /etc/gdm/PostSession/Default
  done
  IFS=$OLD_IFS
  echo "$OUTPUT"
}

# the following 2 lines were added by toobuntu on 080828:
kill -9 $( ps U "${USER}" | grep -v TTY | mawk '{print $1}' ) 2> /tmp/kill-stragglers-gdm.errors
/etc/init.d/gdm restart

exit 0

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FYI- From http://www.gnome.org/projects/gdm/docs/2.14/configuration.html :

When the user terminates his session, the PostSession script will be run. Again operation is similar to Init, PostLogin and PreSession. Again the script will be run with root privileges, the slave daemon will block and the $USER environment variable will contain the name of the user who just logged out and $DISPLAY will be set to the display the user used, however note that the X server for this display may already be dead and so you shouldn't try to access it. Also $X_SERVERS environmental variable is set and this points to a fake generated X servers file for use with the sessreg accounting application.

Note that the PostSession script will be run even when the display fails to respond due to an I/O error or similar. Thus, there is no guarantee that X applications will work during script execution.