Code review comment for lp:~jelmer/launchpad/noversion

Hi Abel,

On Mon, 2010-03-15 at 08:45 +0000, Abel Deuring wrote:
> On 12.03.2010 19:52, Jelmer Vernooij wrote:
> >> On 12.03.2010 11:43, Jelmer Vernooij wrote:
> >>> This test already existed, I've just changed it to use assertEquals.
> >> Right, but you changed the implemention of the tested class, so this is
> >> a genuine test failure ;)
> > Yep - thanks, I'm not sure how I missed that.
> >
> >>> Older versions of Launchpad also had this behaviour and it's required by
> >> Debian policy. It looks like older versions of python-debian considered 1.0 <
> >> 1.0-0.
> >> OK. But the is question why this "relaxed equality comparison" was
> >> introduced and even tested, and if we can remove it again.
> > It was inherited from sourcerer and this is mainly a theoretical situation. "0" should never be used as the debian revision and it would only ever apply anyway if somebody changed a native package to no longer be native while keeping the upstream version the same *and* using 0 for the debian revision.
> >
> > Still, it would be nice to get right just in case somebody happens to ever do something like that. It would be confusing if dpkg and launchpad behaved differently. I've filed a bug against apt in debian about this and noted it in the source code.
>
> OK, so, what shall we do with this test failure? Adjust the test or
> change the __cmp__ method of the tested class?
The __cmp__ not working properly is actually a bug deep down in apt, so
I've filed a bug against it in Debian and disabled the test for now.

> I have no clue if the new comparison may have any side effects on other
> code -- I simply don't understand enough about Soyuz and the fine
> details about Debian packages in general.
I'm quite sure this shouldn't have any side effects.

> Can/should we simply ensure that version strings without the "-0" are
> rejected? That would make the test obsolete. (Do we already have
> packages where this "-0" is missing?)
It's the other way around - -0 would be missing generally, I don't think
there is anybody using -0 at the moment. I guess we could refuse
packages with a "0" Debian revisions for now, I'll ask if that'd be
acceptable.

> If we keep the new comparison: Can it happen that we have two package
> versions 1.0 and 1.0-0? How would Launchpad deal with these packages?
> And how would apt, dpkg and other package management tools deal with
> these versions?
No, we can't have both a package without and with -0 because they would
be deemed the same package, would need to have the same MD5sum (but
can't because their debian/changelog file would differ).

Cheers,

Jelmer