Bug#593177: Clarify when dependencies of pre-dependencies are satisfied

[Jonathan Nieder <jrnieder@gmail.com>]

Jonathan Nieder wrote:

>                                                               this
> is about preinst only, which basically means (based on a quick search)
> pseudo-essential packages and debconf.

Hmm, and python-ure.

Maybe we should treat all dependencies of a pre-dependency as
pre-dependencies after all.

This is not entirely analagous to the case of dependencies of an
essential package because, as Russ said, a maintainer of a (library,
say) package may not know in advance whether it will appear as a
pre-dependency.

Dependency loops in packages that appear as a pre-dependency are
forbidden, anyway.  So it might be doable.