Re: [PATCH 7/7] xdiff: make diff3 the default conflictStyle

From: Felipe Contreras <felipe.contreras@gmail.com>
To: Sergey Organov <sorganov@gmail.com>,
	Felipe Contreras <felipe.contreras@gmail.com>
Cc: "Johannes Sixt" <j6t@kdbg.org>,
	"Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
	"David Aguilar" <davvid@gmail.com>,
	"Bagas Sanjaya" <bagasdotme@gmail.com>,
	"Elijah Newren" <newren@gmail.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Denton Liu" <liu.denton@gmail.com>,
	git@vger.kernel.org
Subject: Re: [PATCH 7/7] xdiff: make diff3 the default conflictStyle
Date: Fri, 11 Jun 2021 13:10:13 -0500	[thread overview]
Message-ID: <60c3a7058af24_8d0f20833@natae.notmuch> (raw)
In-Reply-To: <87bl8ce1ug.fsf@osv.gnss.ru>

Sergey Organov wrote:
> Felipe Contreras <felipe.contreras@gmail.com> writes:
> 
> > Johannes Sixt wrote:
> >> then diff3 must display the conflict as
> >> 
> >>  12<ABC|34=AXC>56
> >> 
> >> to be technically correct. RCS style can coalesce A and C outside of the
> >> conflict and display it as
> >> 
> >>  12A<B=X>C34
> >> 
> >> and *that* is the helpful part of this simpler style.
> >
> > I have trouble translating the above to what I'm familiar with in my
> > mind, so...
> >
> > diff2:
> >
> >   1
> >   2
> >   A
> >   <<<<<<< l
> >   B
> >   =======
> >   X
> >   >>>>>>> r
> >   C
> >   5
> >   6
> >
> > diff3:
> >
> >   1
> >   2
> >   <<<<<<< l
> >   A
> >   B
> >   C
> >   ||||||| b
> >   3
> >   4
> >   =======
> >   A
> >   X
> >   C
> >   >>>>>>> r
> >   5
> >   6
> >
> > I personally don't mind at all having a few extra lines in order to
> > visualize what actually happened.
> 
> Plus a good tool should have an option to quickly show a diff between any
> 2 of 3 parts, making analysis even simpler.

Indeed, it depends on the mergetool, but personally I use vimdiff3
(which I authored). All I need are diff3 conflict markers plus some
colors.

> > But of course there's zdiff3:
> >
> >   1
> >   2
> >   A
> >   <<<<<<< l
> >   B
> >   ||||||| b
> >   3
> >   4
> >   =======
> >   X
> >   >>>>>>> r
> >   C
> >   5
> >   6
> >
> > Which is the best of both worlds, even if not technically accurate.
> 
> Yeah, now I see, thank you both for explanations!
> 
> That said, to me it seems that for any of 3 formats one can find a case
> where it's better than the other 2. I'm sure I got a few occasions where
> leaving common part(s) out of conflicts resulted in a confusion and
> mis-merge.

Yes, and I found it curious that all this sprang up from my suggestion
to get out of our comfort zones.

Since I don't have my beloved `g mt` alias, I've been forced to do
`g mergetool --tool=gvimdiff3`, once there, I decided to use gvimdiff2 a
couple of times, and I even gave meld a try.

Now, I didn't dare to remove merge.conflictstyle from my config, but if
I did, I would I have immediately noticed that:

  git merge --<tab>

There's nothing to easily switch conflict styles.

Seems like there's many areas of opportunity.

Cheers.

-- 
Felipe Contreras