Re: Idea: Git Bundle V3 capability @HEAD=ref/heads/<name>

From: brian m. carlson <sandals@crustytoothpaste.net>
Date: Oct 7, 2022, 09:02 UTC
Message-ID: <Yz/rAHYi8JKylHqy@tapette.crustytoothpaste.net>
In-Reply-To: <037901f1-1649-1485-a853-9783b9d43b31@iee.email>

On 2022-10-06 at 15:55:49, Philip Oakley wrote:

Show 21 quoted lines

> In brian's recent work on V3 bundles [1, et al] I spotted a potential
> idea for resolving the long standing problem that the bundle code may
> need to guess at which ref HEAD was pointed [2, et al] at when there
> were two branches that pointed at the same HEAD oid.
> 
> The basic idea is to utilise the new 'capabilities' field to pass the
> particular ref that is HEAD using a 'HEAD' capability
> i.e. sending the capability    @HEAD=ref/heads/<name>
> 
> It's inclusion in the header wouldn't change the pack in any way, and
> would resolve the guessing problem.
> 
> It would be optional for those that don't want to explictly export the
> HEAD ref's name, and could be also protected by requiring that HEAD is
> listed in the pack, and maybe that the ref it points to is also
> included, and maybe further that there is an alternate ambigous ref listed.
> 
> The idea of the HEAD capability could also be extended to the transport
> layer, as well as this bundle sneaker-net layer.
> 
> Are there reasons why it couldn't work before I put it on my list of ideas?

I think this is a great idea. I might suggest "symref=HEAD:refs/heads/<name>" simply because it allows us to specify more than one symref if we feel like it in the future, but otherwise I have no objections.

I'm glad someone's finding my v3 bundle work more generally useful.

-- 
brian m. carlson (he/him or they/them)
Toronto, Ontario, CA