no effect with custom DisplayManager*cpp

[john smith]

After playing around with custom toolchain and renaming /usr/bin/cpp
to /usr/bin/cpp.bak I noticed that xdm looks different.  I tried to
set a path to an old cpp in /etc/X11/xdm/xdm-config like this but it
doesn't work:

DisplayManager*cpp: /usr/bin/cpp.bakkk

By `doesn't work' I mean that xdm still looks different than it used
to be before renaming cpp. Is DisplayManager*cpp option still
supported?
-- 
<wempwer at gmail.com>