From: Jeff King <peff@peff.net>
Date: Wed, 14 Jan 2026 21:11:15 GMT
Subject: Re: [BUG] Git push sends too much data unnecessarily
Message-ID: <20260114211115.GC1008851@coredump.intra.peff.net>
In-Reply-To: <CAGe2LO3t3B1g1ARH-LQ9V0UoGmToO-Z9XYpeMOTKkaSQvCpaRA@mail.gmail.com>

On Wed, Jan 14, 2026 at 05:39:43PM +0000, Rajiv Sharma wrote:

> > This boils down to how Git negotiates between the client <> server
> 
> I think that's the crux of the problem here. I don't think git
> negotiates in the push path the way it does in the read path, i.e.
> there is no process of client-server communication that involves
> gradually arriving at the common base (in this case it would be C3).
> The read path does this quite well (using something akin to a skiplist
> IIRC?) and the common base is found in a couple iterations in most
> cases. I am unaware of the historical context behind this difference
> but I assume the server sending unnecessary extra data during the read
> path would be much more expensive than the client doing it hence the
> push protocol is kept simpler.
> 
> This kind of negotiation _could_ be added to the push path but it
> would be a breaking change. I read somewhere that there were plans for
> Push Protocol V2 (in the same vein as Read Protocol V2) so it would be
> great to see this improvement making its way there!

I think you may have misunderstood Junio's response. We do have
push.negotiate already. It's just not the default.

Did you try your example with "git -c push.negotiate=true push ..."?

-Peff