From: Han-Wen Nienhuys <hanwen@google.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Han-Wen Nienhuys via GitGitGadget <gitgitgadget@gmail.com>,
git <git@vger.kernel.org>, Han-Wen Nienhuys <hanwenn@gmail.com>
Subject: Re: [PATCH v3 0/3] Remove special casing for PSEUDOREF updates
Date: Wed, 5 Aug 2020 12:48:21 +0200 [thread overview]
Message-ID: <CAFQ2z_NU4=WcUDvVY9PNs+p-WU4u5=QY+=DHonGyK29numhWoQ@mail.gmail.com> (raw)
In-Reply-To: <xmqq1rklrhle.fsf@gitster.c.googlers.com>
On Wed, Aug 5, 2020 at 3:45 AM Junio C Hamano <gitster@pobox.com> wrote:
> > I'd think all .git/${SOMETHING}_HEAD are of transitory nature that
> > can be left as simple on-disk files that are read (and preferrably
> > written---except for FETCH_HEAD for obvious reasons) as if they are
> > loose refs handled by files backend.
>
> Sorry for flipping and flopping. The above goes directly against
> the spirit of 09743417 (Modify pseudo refs through ref backend
> storage, 2020-07-27). I still think .git/${SOMETHING}_HEAD except
> for FETCH_HEAD should be written and read via the ref subsystem, but
> I was wrong to say that it should always be done via the files
> backend. There is no reason to insist on the use of files backend
> here.
Yes, that confused me. Thanks for setting that straight.
> > If the octopus merge does not finish correctly (e.g. due to
> > conflicts), with "git reset --hard", we can recover to the original
> > state and re-attempt the opeation with "git merge FETCH_HEAD". Such
> > a merge using FETCH_HEAD will produce an octopus merge.
> >
> > Which means that at least "git merge", FETCH_HEAD is not just a
> > regular ref where you can ask what object it points at and it gives
> > you a single object name back.
> >
> > But to other commands like "git log master..FETCH_HEAD", it acts as
> > if there is only one object recorded.
>
> All of which means FETCH_HEAD is special and we may not want to
> burden the special casing of it to newer backends.
Can you confirm that FETCH_HEAD is the only thing that can store more
than just a symref / SHA1 ? Based on the name, and a comment in the
JGit source, I thought that MERGE_HEAD might contain more than one
SHA1 at a time.
--
Han-Wen Nienhuys - Google Munich
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next prev parent reply other threads:[~2020-08-05 11:38 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-06 17:29 [PATCH 0/2] Remove special casing for PSEUDOREF updates Han-Wen Nienhuys via GitGitGadget
2020-07-06 17:29 ` [PATCH 1/2] Modify pseudo refs through ref backend storage Han-Wen Nienhuys via GitGitGadget
2020-07-06 20:26 ` Junio C Hamano
2020-07-07 13:56 ` Han-Wen Nienhuys
2020-07-07 15:20 ` Junio C Hamano
2020-07-07 17:15 ` Han-Wen Nienhuys
2020-07-07 18:14 ` Junio C Hamano
2020-07-06 17:29 ` [PATCH 2/2] Make HEAD a PSEUDOREF rather than PER_WORKTREE Han-Wen Nienhuys via GitGitGadget
2020-07-06 20:30 ` Junio C Hamano
2020-07-07 9:24 ` Han-Wen Nienhuys
2020-07-09 21:11 ` [PATCH v2 0/3] Remove special casing for PSEUDOREF updates Han-Wen Nienhuys via GitGitGadget
2020-07-09 21:11 ` [PATCH v2 1/3] t1400: use git rev-parse for testing PSEUDOREF existence Han-Wen Nienhuys via GitGitGadget
2020-07-09 21:11 ` [PATCH v2 2/3] Modify pseudo refs through ref backend storage Han-Wen Nienhuys via GitGitGadget
2020-07-09 21:11 ` [PATCH v2 3/3] Make HEAD a PSEUDOREF rather than PER_WORKTREE Han-Wen Nienhuys via GitGitGadget
2020-07-10 19:25 ` [PATCH v2 0/3] Remove special casing for PSEUDOREF updates Junio C Hamano
2020-07-16 18:45 ` [PATCH v3 " Han-Wen Nienhuys via GitGitGadget
2020-07-16 18:45 ` [PATCH v3 1/3] t1400: use git rev-parse for testing PSEUDOREF existence Han-Wen Nienhuys via GitGitGadget
2020-07-16 18:45 ` [PATCH v3 2/3] Modify pseudo refs through ref backend storage Han-Wen Nienhuys via GitGitGadget
2020-07-17 8:52 ` Johannes Schindelin
2020-07-27 15:41 ` Han-Wen Nienhuys
2020-07-16 18:45 ` [PATCH v3 3/3] Make HEAD a PSEUDOREF rather than PER_WORKTREE Han-Wen Nienhuys via GitGitGadget
2020-07-16 22:09 ` [PATCH v3 0/3] Remove special casing for PSEUDOREF updates Junio C Hamano
2020-07-27 8:50 ` Han-Wen Nienhuys
2020-07-27 16:20 ` Junio C Hamano
2020-08-03 19:07 ` Han-Wen Nienhuys
2020-08-03 20:07 ` Junio C Hamano
2020-08-05 1:45 ` Junio C Hamano
2020-08-05 10:48 ` Han-Wen Nienhuys [this message]
2020-08-05 15:54 ` Junio C Hamano
2020-08-10 14:27 ` Han-Wen Nienhuys
2020-08-10 16:04 ` Junio C Hamano
2020-08-11 10:49 ` Han-Wen Nienhuys
2020-08-11 18:38 ` Junio C Hamano
2020-08-19 13:19 ` Han-Wen Nienhuys
2020-08-19 15:52 ` Junio C Hamano
2020-07-27 16:25 ` [PATCH v4 " Han-Wen Nienhuys via GitGitGadget
2020-07-27 16:25 ` [PATCH v4 1/3] t1400: use git rev-parse for testing PSEUDOREF existence Han-Wen Nienhuys via GitGitGadget
2020-07-27 16:25 ` [PATCH v4 2/3] Modify pseudo refs through ref backend storage Han-Wen Nienhuys via GitGitGadget
2020-07-27 16:25 ` [PATCH v4 3/3] Make HEAD a PSEUDOREF rather than PER_WORKTREE Han-Wen Nienhuys via GitGitGadget
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