Re: [PATCH] notes: do not drop notes written by a concurrent process

[Junio C Hamano <gitster@pobox.com>]

"Kristoffer Haugsbakk" <kristofferhaugsbakk@fastmail.com> writes:

> Instead, maybe this would happen in an ideal world:
>
> 1. `master` and `feature1` race to commit a note
> 2. `master` wins
> 3. `feature1` notices that there is a new note commit (from `master`)
> 4. It checks whether that commit changed the commit that *it*
>    (`feature1`) wanted to update
>    • If so: fail
>    • If not: continue
> 5. `feature1` retries (go to (1))
>
> Maybe this is too much logic for a “porcelain” command (interactive
> use), but there is no plumbing Notes command.

Or possibly

 1. two races. Both remembers what commit was at the tip of the
    notes tree (call it commit #1).

 2. each creates a new note commit on top of #1.  Call them commit
    #2master and #2feature1.

 3. 'master' one wins the race.  As #2master is a fast-forward from
    #1, the notes tree gets #2master at its tip.

 4. 'feature1' loses the race.  It merges #2feature1 into, or
    rebases #2feature1 on top of, #2master and updates the notes
    tree.

;-)