Comment # 19 on bug 1173402 from Thomas Blume

(In reply to Fabian Vogt from comment #18)
> No, that "$?" is wrong because there is an if preceding it.
> Example:
> if false; then false; fi
> echo $? # 0
> 
> So using $? after an if is not working as expected here, it will only
> indicate
> the exit code of "do_dhcp -4" or "do_dhcp", but never of "do_dhcp -6".

Argh, you are right, took me some time to see it, thanks!

[...]

> Yay, spaghetti...

fully agreed

> > Please note I appreciate your comments and will try to addess them as best
> > as possible, but without breaking anything working.
> > Unfortunately code changes here are very delicate since it has a big impact
> > on netboot.
> 
> Yep, this is the reverse-engineering part of cleanup ;-)
> 
> I don't see any downside to merging the "# No ip lines default to dhcp" block
> with the "# no ip option directed at our interface?" one down below, it would
> make the various options and flows much more obvious.

Ok, working on an update.