Bug 39215 – XSESSION environment variable assigned incorrectly when using xdm

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Soren Harward 2004-01-23 17:45:06 UTC]

Lines 1 and 21-24 of /etc/X11/xdm/Xsession are as follows:

1: #!/bin/bash --login
[...]
21: # handle KDM
22: if [ -n "$1" ]; then
23:         export XSESSION="$1"
24: fi

I'm not really sure how KDM works and uses /etc/X11/xdm/Xsession (if it uses it at all), but this creates a real problem when *not* using XDM and certain inputrc settings with bash.  If "bell-style none" is set, then $1 and $2 of a bash login shell are set to "bell-style" and "none" respectively; try starting a new shell and doing "echo $1 $2" right off the bat to see this.

So when /etc/X11/xdm/Xsession runs, it sets the XSESSION environment variable to "bell-style", which of course makes no sense as an X session type.  This variable propagates through the rest of the XDM startup scripts, overriding anything else the user or administrator has set.  When /etc/X11/chooser.sh tries to find the "bell-style" session, it of course doesn't find anything, and returns the default "/usr/X11R6/bin/twm".  As a result, the user finds that not only his ~/.xsession ignored, but the XSESSION variable he set in /etc/rc.conf is ignored as well.

Commenting out lines 22-24 of /etc/X11/xdm/Xsession fixes this problem.  If it exists, the user's ~/.xsession is run, and if it doesn't exist, the system-wide Xsession runs properly.

Again, I don't run KDM, so I don't know exactly what /etc/X11/xdm/Xsession is expecting to receive from it on $1.  It sure isn't expecting "bell-style".

[Comment 1 ferret 2004-01-27 13:28:11 UTC]

I can't confirm this behaivour. I have

set bell-style none

in my /etc/inputrc and I certainly don't get that echoed when I do

echo $1 $2

whether login shell or no.

[Comment 2 Florian Lüke 2005-01-16 10:44:59 UTC]

A quote from the bash manpage (first paragraph of the 'set' builtin command):
"Any arguments  remaining after the options are processed are treated as values
for the positional parameters and are assigned, in order, to $1, $2,  ...   $n."

While testing with a small shellscript I noticed that if any parameters are
passed via the commandline, the parameters created by 'set' are discarded.
Unfortunately I didn't see this behaviour mentioned in the documentation.

So this error only happens if the user has additional arguments to 'set' in
his ~/.bashrc _and_ if there are no parameters passed to the Xsession script
(which is the case if using xdm as the login manager).

A solution would be to check if DISPLAYMANAGER is set to "kdm" (or any other
displaymanager that expects parameters) in /etc/rc.conf and to only execute
lines 22-24 if this test is true.

[Comment 3 John N. Laliberte (RETIRED) 2005-10-15 18:19:49 UTC]

please see
http://bugs.gentoo.org/77447
it may be related to this ( and now resolved ).

[Comment 4 Donnie Berkholz (RETIRED) 2006-04-04 15:10:49 UTC]

If this remains a problem with modular X, please reopen.