Re: [PATCH 1/2] Change default merge backend from recursive to ort

From: Elijah Newren <newren@gmail.com>
To: Philippe Blain <levraiphilippeblain@gmail.com>
Cc: "Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>,
	"Git Mailing List" <git@vger.kernel.org>,
	"Christian Couder" <chriscool@tuxfamily.org>,
	"Derrick Stolee" <dstolee@microsoft.com>,
	"Emily Shaffer" <emilyshaffer@google.com>,
	"Eric Sunshine" <sunshine@sunshineco.com>,
	"Jeff King" <peff@peff.net>,
	"Johannes Schindelin" <Johannes.Schindelin@gmx.de>,
	"Jonathan Nieder" <jrnieder@gmail.com>,
	"Jonathan Tan" <jonathantanmy@google.com>,
	"Junio C Hamano" <gitster@pobox.com>,
	"Phillip Wood" <phillip.wood@dunelm.org.uk>,
	"René Scharfe" <l.s.r@web.de>, "Taylor Blau" <me@ttaylorr.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Subject: Re: [PATCH 1/2] Change default merge backend from recursive to ort
Date: Mon, 2 Aug 2021 21:39:51 -0600	[thread overview]
Message-ID: <CABPp-BGJ_ZfOPRdsjxnT8q9r9YPZUsnSmPoT0xuwJRJ3TN4wWA@mail.gmail.com> (raw)
In-Reply-To: <49b61447-06b7-9c43-fdd6-25adc45f2a88@gmail.com>

Hi Philippe,

On Mon, Aug 2, 2021 at 8:56 PM Philippe Blain
<levraiphilippeblain@gmail.com> wrote:
>
> Hi Elijah,
>
> Le 2021-07-31 à 20:07, Elijah Newren via GitGitGadget a écrit :
> > From: Elijah Newren <newren@gmail.com>
> >
> >
> >    * `git diff AUTO_MERGE` -- ability to see what changes the user has
> >      made to resolve conflicts so far (see commit 5291828df8 ("merge-ort:
> >      write $GIT_DIR/AUTO_MERGE whenever we hit a conflict", 2021-03-20)
> >
> >
> > The last three have been implemented already (though only one has been
> > submitted upstream so far;
>
>  From what I could find this indeed only refers to your 5291828df8 (merge-ort:
> write $GIT_DIR/AUTO_MERGE whenever we hit a conflict, 2021-03-20).
> This is a very nice improvement, but I noticed it is not mentioned in the doc.
> Do you plan to update the 'git diff' doc to mention that special ref ?
> (And maybe also gitrevisions(5), where most of the special refs are listed ?)
>
> Do you plan to implement a new '--auto-merge' option to 'git diff' as a shortcut
> to 'git diff AUTO_MERGE', in order to hide a bit the special ref from users ?

Fair point, it probably does deserve to be documented somewhere, at
least once ort is the default merge algorithm.

I don't think it'd make sense to include a reference to it in
gitrevisions(5), since $GIT_DIR/AUTO_MERGE is a reference to a tree
rather than to a revision.  But documenting that special ref in
Documentation/git-diff.txt, and perhaps linking to it from other
conflict-related options (e.g. --base, --ours, --theirs) may make
sense.  Your --auto-merge idea may also make sense, and it'd be
somewhat similar to how git-rebase has a --show-current-patch option
that is shorthand for `git show REBASE_HEAD` and is documented as
such.  However, it might be confusing to users how to combine
--auto-merge with paths, whereas `git diff AUTO_MERGE -- pathname` is
pretty clear once you know that AUTO_MERGE is a tree you can diff
against.  Hmmm....