Bug#742671: seeding base-installer/debootstrap_script with an absolute path emits a warning, and just a codename results in an error

[Margarita Manterola <margamanterola.bugs@gmail.com>]

Hey there!

It's been a couple of years, but base-installer and debootstrap are
still in this odd state where base-installer wants the script to be
just the distribution and debootstrap wants it to be the full path.
So, whatever you put in the preseed you get an error (alas, the
base-installer one isn't fatal, so at least that works).

Tianon's patch is really simple, and not only does it fix the problem,
but also makes preseeding more flexible. Can it be applied please?

--
Thanks!
Marga