Re: Zero epoch vs no epoch (patch)

On Sat, 29 Apr 2006, Panu Matilainen wrote:

> > >  - Even if no epoch is specified, the metadata still specifies this 
> > >    as "0".  For most code paths this is no problem as for all 
> > >    comparisons of version data, a missing epoch is the same as a "0" 
> > >    epoch. This should not be a huge problem and would be only a 
> > >    cleanup item for the repodata.
> >
> > what does removing 0-epoch items buy us?
> 
> What it buys is support for ancient rpm versions. Remember those 
> monstrosities where non-existing epoch is not equal to zero epoch, epoch 
> promotion and all that fun? I couldn't personally care less about the 
> old rpm versions but there are people who do care, for example Dag and 
> Matthias: 
> http://lists.freshrpms.net/pipermail/freshrpms-list/2006-April/014022.html
> 
> Removing those zero epochs from repodata makes yum rather unhappy, dunno 
> about smart, so changing the default is not really a possibility. But 
> then neither supports the prehistoric versions that are of concern here. 
> Attached quick hack of a patch adds a switch to turn off adding those 
> artificial zero epochs, using this as necessary this should be enough to 
> allow using repodata with full rpm 3.0.x - 4.4.x range.

When we were implementing rpm-md support for our online update channels, 
we stumbled over the epoch thingy as well, but had to add the epoch="0", 
to keep yum & smart intact. The funny thing we found was the fact that rpm 
itself doesn't handel an empty epoch consistently -- if there is any 
interest, I'll dig into the rpm code again to give you the details...


Regards
	Christoph