git: skip fetch if the revision already exists

[jaredgrubb]

Background: I am working on a "richer" git experience with buildbot, where I can reliably get tags, work with multiple remote servers (for the same repo), and share git-objects on the slaves to avoid multiple builders doing redundant network fetches.

The current Git step is not quite sufficient because it seems (correct me if I'm wrong) to take a conservative view of working with a git-server: to only fetch the minimal amount needed.

So, this patch doesnt actually fix anything, so maybe it's not worth taking. But I thought I would post it.

[sa2ajj]

PEP8:

master/buildbot/steps/source/git.py:368:18: E225 missing whitespace around operator
            if rc==RC_SUCCESS:
                 ^
1       E225 missing whitespace around operator
1
make: *** [pep8] Error 1

[sa2ajj]

This looks a bit cleaner for me.

👍

[jaredgrubb]

Pushed the pep8 fix.