The file /etc/X11/xdm/Xsession is not the original XFree86
one. It has been enhanced - probably by Red Hat.

This enhancement has introduced a bug in line 54:
	    exec "$startup $@"
where:
* "$startup" is $HOME/.xsession
* "$@" is whatever options are passed to the script
  by xdm or an equivalent program.
The script will try to exec a file in the $PATH with
the name "$startup $@" instead of a program with the
name "$startup" followed by command-line arguments "$@".


To fix this problem, change line 54 from
	    exec "$startup $@"
to
	    exec "$startup" "$@"



I am trying to install KDE and its kdm display manager.
In kdm, the user is able to choose the type of the session
- `failsafe' or `kde' or `CDE' or `fvwm' or whatever.
I have added an .xsession file to my home directory.
If I choose any session type that is not `failsafe',
let's say `kde', the script fails because it tries to
exec "/home/papadopo/.xsession kde".

I want to modify as few system files as possible. I chose
to create a .Xclients file instead of a .xsession file in
my home directory. The drawback is that no session type
argument is passed anymore from  /etc/X11/xdm/Xsession to
.Xclients: I can only choose between `failsafe' which is
handled directly in /etc/X11/xdm/Xsession and another
environment defined in .Xclients.