chsh.moira shouldn't use /etc/shells

[jdreed]

chsh.moira should not use /etc/shells as the list of acceptable shells, since that list is not static. Really, it should yell very loudly at you if you try and change your shell to anything other than /bin{,/athena}/{tc,ba}sh.

For example, if I run chsh.moira on Linerva, and choose zsh, that will be fine, since zsh is installed on Linerva. If I then log into a cluster machine, I will be very sad and will end up with weird screw cases. For example, I can launch gnome-terminal (which will run bash for me, for some reason), but not xterm (which will error out saying /usr/bin/zsh does not exist).

We can either use a file in AFS (and require AFS), or we can ship /etc/shells.moira which contains /bin/athena/bash, /bin/athena/tcsh, /bin/bash, and /bin/tcsh.

Ideally, we'd follow up and change this upstream.

[jdreed]

Alternatively, we ship /etc/shells.moira, which contains the "official" choices. If a shell is not in there, but is in /etc/shells, inform the user that this may screw them over. If a shell is not listed in either location, prevent the user from selecting it.

[lizdenys]

Submitted in  moira:5673

[lizdenys]

Fixed moiradev's issue with sysconfdir and resubmitted the patch in  moira:5674

[jdreed]

This got taken upstream.

[geofft]

We also need to install it in our packaging. Fixed in r25344.

[jdreed]

Guess why this didn't work when Geoff tested it:

#ifndef HAVE_GETUSERSHELL

[jdreed]

This was fixed in r4048 and now works, but deployment is blocking on #888.

jdreed@infinite-loop:~$ grep ksh /etc/shells
/usr/bin/ksh
/bin/ksh
jdreed@infinite-loop:~$ grep ksh /etc/shells.moira
jdreed@infinite-loop:~$ chsh.moira 
Changing login shell for jdreed.
Finger information last changed on 29-aug-2011 11:24:50
by user jdreed@ATHENA.MIT.EDU with chsh.
Current shell for jdreed is /bin/athena/bash.
New shell: /bin/ksh
/bin/ksh is not available.
jdreed@infinite-loop:~$