The None argument is always <= than the other argument. We need this
in case of a broken/pathological package where version() or release()
return None (see vercmp (which calls rpmvercmp)).
Returning None breaks ArchQuery.vercmp. Returning b'0' is ok because
an epoch, if present, is always supposed to be an integer (at least
in a "valid" arch package (see scripts/libmakepkg/lint_pkgbuild/epoch.sh.in
in the pacman sources)). Hence, if we compare the epoch of a package,
which has no explicit epoch set, with the epoch of a package, which
has an explicit epoch set, we always have a <= relation.
The following abstract methods are added to the PackageQueryResult
class: recommends(), suggests(), supplements(), and enhances().
Note that not all package/metadata formats have a notion of these
weak dependencies.
rpm rpmmd deb arch
recommends x x x
suggests x x x x
supplements x x
enhances x x x
(where "x" represents "supported"). In case of an unsupported weak
dependency, the implementation returns an empty list.
We need the weak dependency support in order to fix#363 ("osc build
-p ../rpms/tw doesnt send recommends to the server which makes client
side build behave differently to server side build").
The most visible change in python3 - removal of print statement and all
the crufty
print >> sys.stderr, foo,
The from __future__ import print_function makes it available in python
2.6
