Re: [PATCH 5/6 (v2)] upload-pack: send the HEAD information

On Mon, Dec 01, 2008 at 06:12:54AM -0800, Junio C Hamano wrote:

Yuck. My two complaints are:

  (1) this implicitly handles only the HEAD symref. I don't think any
      others are in common use, but the rest of git handles arbitrary
      symrefs just fine. It would be a shame to needlessly limit the
      protocol. Can we at least make it <ref>:<ref> to allow later
      expansion to other symrefs?

      (1a) As a follow-on to that, because the client is not requesting
      anything, how would we ask for other symrefs if we want to do so
      later?  I think it would be nice to eventually allow copying of
      arbitrary symrefs within the refs/* hierarchy (e.g.,
      project-specific branch aliases). Sending all symrefs right off
      the bat is potentially large and wasteful.

  (2) You've used up the first such expansion slot forever. Now it's "if
      I want to tell you the symref, there is an extra slot, and
      otherwise none". But if we ever want to use the _next_ slot, then
      you will always have to send this slot (blank, I guess?). It gets
      even more complicated if you ever want to an arbitrary number of
      symref mappings. Maybe a short header to say "this slot contains a
      symref target"?

So (1) and (2) together would make it something like:

   <capabilities>\0
   symref HEAD:refs/heads/master\0
   symref refs/heads/alias:refs/heads/branch\n

which would make adding any new features in the expansion slots easier. But that still doesn't address (1a). I really like the other proposal a lot better.

-Peff