Re: [PATCH 2/2] transport-helper: update remote helper namespace

[Jeff King <peff@peff.net>]

On Wed, Apr 10, 2013 at 07:07:12PM -0500, Felipe Contreras wrote:

> When pushing, the remote namespace is updated correctly
> (e.g. refs/origin/master), but not the remote helper's
> (e.g. refs/testgit/origin/master).
> 
> Let's update it correctly.

I would have thought it was the helper's responsibility to update these.
Obviously remote-testgit can handle this fine, but will any other
helpers be using these refs as a marker to know the last point they
imported, and get confused if we update the refs behind their back?

For example, during the import, a helper might know that it has imported
up to X on a foreign vcs, and that resulted in commit Y in git, which it
stored in refs/$helper/heads/master during the last import. When we
fetch from it again, it picks up from X to the tip of the foreign vcs,
and then imports that history on top of commit Y.

But if we push some commits to the helper, moving Y up to Z, then it
would build the new commit (which contains the foreign-vcs's equivalent of
Y..Z) on top of Z, not Y.

I do not offhand know of any helpers that are implemented this way,
though. vcs-svn does not seem to use the refspec feature at all, and I
assume that your hg/bzr helpers do not have this problem. So perhaps it
is not worth worrying about.

-Peff