I've reopened this bug because xdm 1:1.0.1-5 remains broken exactly as before; xdm-config refers to a nonexistant Xsetup_0, and if I fix that xdm still fails on login with this in the log:
error opening security policy file /usr/lib/xserver/SecurityPolicy (Note: I purged xdm and reinstalled it, this is not old conffiles.) -- see shy jo
