No more autologin in live CD

[Didier Roche-Tolomelli]

Binary package hint: casper

Similarly to bug #500786, the custom.conf file is messed up again without \n interpretation:
[daemon]
AutomaticLoginEnable=true\nAutomaticLogin=didrocks\nTimedLoginEnable=true\nTimedLogin=didrocks\nTimedLoginDelay=10

The issue is in 15autologin:
printf '[daemon]\n%s' "$AutologinParameters" >> $GDMCustomFile
changed in 1.212:
  * 15autologin: Use printf rather than echo -e, since its behaviour is
    portable across shells.

The first \n is interpreted contrary to those in $AutologinParameters (probably %s take the string content vanilla). I didn't found any option to switch that. So, I reverted to echo -e for now.

---------------
casper (1.213) UNRELEASED; urgency=low

  * 15autologin: revert to echo -e as printf doesn't interpret \n in
    '%s' string.

[Colin Watson (cjwatson)]

From IRC:

Sorry about the breakage. However, I *really* don't like using echo -e; it has a habit of producing weird side-effects later when things are run under a shell you didn't expect. How about this trick to ensure that the same syntax is acceptable in either case?

  sed -i "\$s/\$/\n$AutologinParameters/" >> $GDMCustomFile

[Didier Roche-Tolomelli (didrocks)]

Colin, I'll rather propose that (simplifying the code):

     # Prevent from updating if parameters already present (persistent usb key)
     if ! `grep -qs 'AutomaticLoginEnable' $GDMCustomFile` ; then
        if ! `grep -qs '\[daemon\]' $GDMCustomFile` ; then
            printf '[daemon]' >> $GDMCustomFile
        fi
        sed -i "s/\[daemon\]/\[daemon\]\n$AutologinParameters/" $GDMCustomFile
     fi

With that, we handle every cases:
- no GDMCustomFile, create the autologin part with [daemon]
- GDMCustomFile already exists with [daemon] section but without the autologin part (case of ubutu derivatives): add it
- GDMCustomFile exists without [daemon] section: add all the autologin stuff and the section (don't know if that can happen with current GDM implementation, but it'll surely later)
- GDMCustomFile exists with [daemon] section and autologin stuff in place (case of persistent usb key): don't do anything

And we get our \n interpreted by sed :)
This new proposal is in my linked branch.

[Evan (ev)]

For what it's worth, I uploaded a changed casper that fixes the immediate issue, before being made aware of this discussion. It's casper 1.213.

My sincerest apologies for missing this.

[Launchpad Janitor (janitor)]

This bug was fixed in the package casper - 1.214

---------------
casper (1.214) lucid; urgency=low

  * 15autologin: simplify the code with escape character evaluation
    (LP: #505140)
 -- Didier Roche <email address hidden> Tue, 12 Jan 2010 08:57:05 +0100