From: Sergey Organov <sorganov@gmail.com>
To: Elijah Newren <newren@gmail.com>
Cc: "Roland Jäger" <eyenseo@mailbox.org>,
"Junio C Hamano" <gitster@pobox.com>,
usbuser@mailbox.org, "Git Mailing List" <git@vger.kernel.org>
Subject: Re: Unexpected or wrong ff, no-ff and ff-only behaviour
Date: Wed, 10 Jul 2019 17:36:20 +0300 [thread overview]
Message-ID: <87y316gdnf.fsf@osv.gnss.ru> (raw)
In-Reply-To: <CABPp-BHpkcOSkTrNDPGWRgSJgbqkc0PRqMqmesg7tQdS5TfMDA@mail.gmail.com> (Elijah Newren's message of "Tue, 9 Jul 2019 09:35:09 -0700")
Hi Elijah,
Elijah Newren <newren@gmail.com> writes:
> Hi Roland,
>
> On Tue, Jul 9, 2019 at 9:17 AM Roland Jäger <eyenseo@mailbox.org> wrote:
>>
>> Thanks for answering Junio.
>>
>> I get what git does. But I believe that either the documentation ist
>> wrong/ambiguous or --no-ff and --ff-only should be able to be
>> combined and either should be fixed - preferably the later. What I
>> want to say to git is "I never accept a real merge; please make a
>> merge commit, even if it is redundant/empty". And I believe that
>> github and gitlab allow to configure something like that.
>
> Please don't top-post on this list.
>
> I agree, the documentation is wrong or misleading and there is a
> wording change we could make to improve it. But, in particular,
> --no-ff and -ff-only are completely incompatible.
They currently are compatible, but in a weird manner, see below.
I'd prefer they were perfectly compatible and orthogonal, as using both
would be the safe way to create cleanest possible merge -- the one that
introduces on the mainline the /exact/ changes made on side-branch:
--ff-only: tells git to refuse operation (actual merge) if FF is
impossible, that for this particular use-case would ensure the merge, when
actually created, is the "cleanest possible" one
and then
--no-ff: forces git to create actual (cleanest possible) merge commit,
that otherwise it wouldn't, as it defaults to --ff, and --ff-only above
ensures FF is possible.
Right now (in my git 2.10) it seems these options somehow cancel each
other, that is both useless and surprising:
When FF is possible:
$ git merge --ff-only --no-ff side_branch
Merge made by the 'recursive' strategy.
[...]
Good!
$ git reset --hard HEAD~1
[...]
$ git merge --no-ff --ff-only side_branch
Updating eafaed6..b83db07
Fast-forward
[...]
??? I said --no-ff: how comes you did fast-forward?!
When FF is impossible:
$ git merge --ff-only --no-ff side_branch
Merge made by the 'recursive' strategy.
[...]
??? I said --ff-only: how comes you didn't bail out?!
$ git reset --hard HEAD~1
[...]
$ git merge --no-ff --ff-only side_branch
fatal: Not possible to fast-forward, aborting.
Good!
-- Sergey
git version 2.10.0.1.g57b01a3
prev parent reply other threads:[~2019-07-10 14:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-09 9:42 Unexpected or wrong ff, no-ff and ff-only behaviour usbuser
2019-07-09 14:51 ` Junio C Hamano
2019-07-09 16:15 ` Roland Jäger
2019-07-09 16:35 ` Elijah Newren
2019-07-09 17:00 ` usbuser
2019-07-09 20:33 ` Elijah Newren
2019-07-09 20:51 ` Bryan Turner
2019-07-10 7:49 ` usbuser
2019-07-10 16:34 ` Junio C Hamano
2019-07-11 5:13 ` Sergey Organov
2019-07-11 17:03 ` Junio C Hamano
2019-07-12 13:50 ` Sergey Organov
2019-07-12 16:24 ` Elijah Newren
2019-07-15 12:08 ` Sergey Organov
2019-07-12 18:33 ` Junio C Hamano
2019-07-15 12:47 ` Sergey Organov
2019-07-15 16:57 ` Junio C Hamano
2019-07-19 11:00 ` Sergey Organov
2019-07-11 15:46 ` brian m. carlson
2019-07-10 14:36 ` Sergey Organov [this message]
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