Re: Syncing HEAD

> Hi,
>
> When cloning with --mirror, the clone gets its HEAD initialized with
> the value HEAD has in its origin remote. After that if HEAD changes in
> origin there is no simple way to sync HEAD at the same time as the
> refs are synced.
>
> It looks like the simplest way to sync HEAD is:
>
> 1) git remote show origin
> 2) parse "HEAD branch: XXX" from the output of the above command
> 3) git symbolic-ref HEAD refs/heads/XXX
>
> It looks like it would be quite easy to add an option to `fetch` to
> sync HEAD at the same time as regular refs are synced because every
> fetch from an origin that uses a recent Git contains something like:
>
> 19:55:39.304976 pkt-line.c:80           packet:          git< YYYYYYYY
> HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow
> deepen-since deepen-not deepen-relative no-progress include-tag
> multi_ack_detailed no-done symref=HEAD:refs/heads/test-1
> agent=git/2.18.0
>
> which in this example shows that HEAD is a symref to refs/heads/test-1
> in origin.
>
> Is there a reason why no such option already exists? Would it makes
> sense to add one? Is there any reason why it's not a good idea? Or am
> I missing something?
>
> I am asking because GitLab uses HEAD in the bare repos it manages to
> store the default branch against which the Merge Requests (same thing
> as Pull Requests on GitHub) are created.
>
> So when people want to keep 2 GitLab hosted repos in sync, GitLab
> needs to sync HEADs too, not just the refs.
>
> I think this could be useful to other setups than GitLab though.
>
> Thanks,
> Christian.