Improve the way rpm decides what is newer

[Christian Iseli]

On Fri, 20 Nov 2009 18:17:57 -0800, Adam Williamson wrote:
> To me, this is the wrong fix. The problem here isn't RPM's version
> comparison logic, which is perfectly sound. Instead of nerfing up RPM
> comparisons, which are already full of enough hidden mines, we should
> just improve Fedora's package versioning conventions so this doesn't
> happen, or at least happens less often.

Let me try to give 3 examples why I think a Vendor comparison,
with the ordering defined in a config file, can be useful:

1. Some group of people would like to use Fedora for most packages
except kernel, where they want to build a low-latency/whatever-funky
option version.  They create repo with Vendor "Low Latency" and the
folks who are interested to use it add the repo to their yum.conf.d and
put in the config file:
"Low Latency" > "Fedora Project"
and I think they'll get what they want, even if they do not keep
exactly in sync with the Fedora repo update.

2. Similarly, if a user wishes to rebuild some of the Fedora packages
using different compiler options because they think the execution speed
will be improved on their hardware, they can simply rebuild the SRPM
with the tweaked options and define Vendor as "My Fedora", and put:
"My Fedora" > "Fedora Project"
and they can then happily continue to receive Fedora updates for the
packages they did not tweak and not worry that their tweaked packages
will be replaced.

3. Suppose repo from Vendor "Funky Repo" provides some not-available
elsewhere packages, but it also offers a mix of rebuilt packages from
Fedora which you would rather not use, in this case you could add the
repo and put in config:
"Funky Repo" < "Fedora Project"
and so yum would only select there packages that are not found in
Fedora.

Cheers,
					Christian