postrm is in gnome-session 3.2.1-0ubuntu8.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 | #!/bin/sh
set -e
case "$1" in
remove|purge)
if [ -x /usr/lib/lightdm/lightdm-set-defaults ] ; then
/usr/lib/lightdm/lightdm-set-defaults --remove --session=ubuntu || true
fi
;;
esac
|