[Yum-devel] RFC: Package object comparison -- do we need a slight change?

[seth vidal]

On Wed, 2006-10-11 at 22:58 -0400, seth vidal wrote:
> On Wed, 2006-10-11 at 22:54 -0400, Jeremy Katz wrote:
> > On Wed, 2006-10-11 at 22:37 -0400, seth vidal wrote:
> > > On Wed, 2006-10-11 at 22:22 -0400, Jeremy Katz wrote:
> > > > > I get where you're coming from about the comparison - I'm just worried
> > > > > about the next requested step:
> > > > >   - take arch into account when dealing with < > comparisons
> > > > 
> > > > I thought about it when we first brought it up and I think we even
> > > > talked about it.  Arguably, we should add it for consistency as it only
> > > > makes things "more" correct.  The problem comes in (slightly) with
> > > > multiarch where you might want to install both equal version but
> > > > different arch'd packages.  From a quick look, though, we'd actually be
> > > > safe to do so.
> > > 
> > > arch is a problem b/c it means the comparison methods have to know about
> > > what your current arch is and the chroot and what you SAY your arch is
> > > (re: /etc/rpm/platform) etc etc etc. It's not something that we could
> > > easily bottle up inside a comparison method.
> > 
> > Right, let's just forget this part for now :-)
> > 
> > > > [snip]
> > > > > It almost feels like we should never allow rich comparison against
> > > > > non-matching archs. Which might be an argument for how to keep someone
> > > > > from doing this accidentally.
> > > > 
> > > > I'm not sure how you keep people from doing it, though -- except by not
> > > > having the comparison operators at all.  And I think we might be stuck
> > > > there now :/
> > > 
> > > well, like I said on jabber
> > > 
> > > if other.arch != po.arch:
> > >     raise InvalidComparisonError, foo foo foo
> > >
> > > but you're correct that will definitely break people's code.
> > > 
> > > I'm not sure I see a happier way.
> > 
> > A quick look through the code shows a few places in yum proper where we
> > seem to expect that po1 == po2 if and only if po1.pkgtup == po2.pkgtup.
> > So, I think that going with my patch (plus also checking arch) might
> > give what most things are expecting...
> 
> + doing a name comparison on the eq/ne as well.
> 
> b/c foo-1.1-1.i386 != bar-1.1-1.i386
> 

Sadly worthy of note:

https://lists.dulug.duke.edu/pipermail/yum-devel/2006-August/002422.html

-sv