Comment 9 for bug 1239893

I tested this and it works in expand_ppa_line of ppa.py but I'm not sure that's the best spot for it.

def expand_ppa_line(abrev, distro_codename):
    """ Convert an abbreviated ppa name of the form 'ppa:$name' to a
        proper sources.list line of the form 'deb ...' """
    # leave non-ppa: lines unchanged
    if not abrev.startswith("ppa:"):
        return (abrev, None)
    # FIXME: add support for dependency PPAs too (once we can get them
    # via some sort of API, see LP #385129)
    abrev = abrev.strip().split(":")[1]