Re: [PATCH] notes: handle multiple worktrees

[Johan Herland <johan@herland.net>]

On Wed, Jul 29, 2015 at 12:12 AM, Junio C Hamano <gitster@pobox.com> wrote:
> David Turner <dturner@twopensource.com> writes:
>> Prevent merges to the same notes branch from different worktrees.
>> Before creating NOTES_MERGE_REF, check NOTES_MERGE_REF using the same
>> code we use to check that two HEADs in different worktrees don't point
>> to the same branch.  Modify that code, die_if_checked_out, to take a
>> "head" ref to examine; previously, it just looked at HEAD.
>>
>> Reported-by: Junio C Hamano <gitster@pobox.com>
>> Signed-off-by: David Turner <dturner@twopensource.com>
>> ---
>
> Thanks for following through.  As I didn't report anything, I do not
> deserve that label, but it's OK ;-)
>
> I know that it is a requirement to protect NOTES_MERGE_REF from
> being used by multiple places for "notes merge" to play well with
> the multi-worktree world order, but because I do not know if that is
> sufficient, I'm asking a few people for further review.

As just stated in a related thread, I don't think it makes sense to
have NOTES_MERGE_REF per worktree, as the notes merge is always
completely unrelated to the current worktree (or the current branch
for that matter). AFAICS this patch is all about handling per-worktree
NOTES_MERGE_REFs, and as such I'm NAK on this patch. Instead, there
should only be one NOTES_MERGE_REF per _repo_, and although we might
want to expand to allow multiple concurrent notes merges in the
future, that is still a per-repo, and not a per-worktree thing, hence
completely unrelated to David's current effort.

...Johan