Bug#195845: xfree86-common: allow-user-xsession does not allow user xsessions
> > When trying to use a .xsession file, I discovered that the functionality
> > doesn't work as it is documented.
>
> How so? I use .xsession files at home and at work, and they work for
> me.
OK, I see why. The problem only happens in the 'program' session type. That's
when the variable STARTUP is incorrectly overwritten with the full path of
the given program.
> > The core problem is on line 29 of 20xfree86-common_process-args, where
> > the variable STARTUP is used to hold the program name of a non-default
> > window manager.
>
> No, it's supposed to hold the name of any program that the display
> manager passes to it. See "SESSION TYPES" in Xsession(5).
>
> > However, STARTUP is supposed to hold the string $HOME/.xsession.
>
> Not really, no. Especially not if $HOME/.Xsession is not executable.
That's the confusion that caused this bug. See line 58 of Xsession:
STARTUP=$HOME/.xsession
And then line 4 of 50xfree86-common_determine-startup:
for STARTUPFILE in "$STARTUP" "$ALTSTARTUP"; do
> Could you please send this bug report a diff so that I can see what you
> actually changed (then I can restore the "patch" tag)?
I've attached two patches here. simple.patch just changes the three lines that
enable allow-user-xsession to work with the 'program'-type session.
morechanges.patch changes some variable names to avoid STARTUP and REALSTARTUP
confusion. Now STARTUP holds the name of the program that will be executed.
There are also two functional changes that I can back out if you want. One is
to pass the program exactly as passed (and not expanding the full patch with
`which $1`). The other is to export the STARTUPPROGRAM variable when a user
is using an .xsession file so that the 'program' selected in the DM can be
used in the .xsession.
Perhaps the names of 20xfree86-common_process-args and
50xfree86-common_determine-startup should be changed to
20xfree86-common_determine-startup and 50xfree86-common_user-xsession because
that is what is happening in them. If you want, I could write up changes to
the doc, too, though I'm not sure about diffing a manpage. :)
> I think it's possible you have changed the conffiles on the system such
> that user sessions are not allowed without further modifications to the
> scripts.
I think that this bug only manifests itself with GDM and KDM when a specific,
non-default startup program is picked. Because you're the XDM maintainer, I
imagine you use that, so don't see the problem.
Let me know if you need anything more.
Frank
diff -r X11/Xsession.d/20xfree86-common_process-args X11.simple/Xsession.d/20xfree86-common_process-args
29c29
< STARTUP=$PROGRAM
---
> REALSTARTUP=$PROGRAM
diff -r X11/Xsession.d/50xfree86-common_determine-startup X11.simple/Xsession.d/50xfree86-common_determine-startup
1,2d0
< REALSTARTUP=
<
diff -r X11/Xsession X11.morechanges/Xsession
58,59c58,59
< STARTUP=$HOME/.xsession
< ALTSTARTUP=$HOME/.Xsession
---
> USERXSESSION=$HOME/.xsession
> USERALTXSESSION=$HOME/.Xsession
diff -r X11/Xsession.d/20xfree86-common_process-args X11.morechanges/Xsession.d/20xfree86-common_process-args
0a1,11
>
> set_default_startup () {
> if [ -x /usr/bin/x-session-manager ]; then
> STARTUP=x-session-manager
> elif [ -x /usr/bin/x-window-manager ]; then
> STARTUP=x-window-manager
> elif [ -x /usr/bin/x-terminal-emulator ]; then
> STARTUP=x-terminal-emulator
> fi
> }
>
2a14
> set_default_startup
23a36
> set_default_startup
26,29c39,42
< PROGRAM=$(which $1)
< if [ -n "$PROGRAM" -a -e "$PROGRAM" ]; then
< if [ -x "$PROGRAM" ]; then
< STARTUP=$PROGRAM
---
> FULLPATHSTARTUP=$(which $1)
> if [ -n "$FULLPATHSTARTUP" -a -e "$FULLPATHSTARTUP" ]; then
> if [ -x "$FULLPATHSTARTUP" ]; then
> STARTUP="$1"
diff -r X11/Xsession.d/50xfree86-common_determine-startup X11.morechanges/Xsession.d/50xfree86-common_determine-startup
1,2d0
< REALSTARTUP=
<
4,7c2,9
< for STARTUPFILE in "$STARTUP" "$ALTSTARTUP"; do
< if [ -e "$STARTUPFILE" ]; then
< if [ -x "$STARTUPFILE" ]; then
< REALSTARTUP=$STARTUPFILE
---
> for XSESSIONFILE in "$USERXSESSION" "$USERALTXSESSION"; do
> if [ -e "$XSESSIONFILE" ]; then
> # Allow .xsession to know the selected session with this variable
> STARTUPPROGRAM="$STARTUP"
> export STARTUPPROGRAM
>
> if [ -x "$XSESSIONFILE" ]; then
> STARTUP="$XSESSIONFILE"
9c11
< REALSTARTUP="sh $STARTUPFILE"
---
> STARTUP="sh $XSESSIONFILE"
16,26c18
< if [ -z "$REALSTARTUP" ]; then
< if [ -x /usr/bin/x-session-manager ]; then
< REALSTARTUP=x-session-manager
< elif [ -x /usr/bin/x-window-manager ]; then
< REALSTARTUP=x-window-manager
< elif [ -x /usr/bin/x-terminal-emulator ]; then
< REALSTARTUP=x-terminal-emulator
< fi
< fi
<
< if [ -z "$REALSTARTUP" ]; then
---
> if [ -z "$STARTUP" ]; then
diff -r X11/Xsession.d/90xfree86-common_ssh-agent X11.morechanges/Xsession.d/90xfree86-common_ssh-agent
16c16
< REALSTARTUP="$SSHAGENT $SSHAGENTARGS $REALSTARTUP"
---
> STARTUP="$SSHAGENT $SSHAGENTARGS $STARTUP"
diff -r X11/Xsession.d/99xfree86-common_start X11.morechanges/Xsession.d/99xfree86-common_start
1c1
< exec $REALSTARTUP
---
> exec $STARTUP
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