Re: [PATCH v2 0/7] Drop support for git rebase --preserve-merges

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sep 7, 2021, 17:33 UTC
Message-ID: <nycvar.QRO.7.76.6.2109071930080.55@tvgsbejvaqbjf.bet>
In-Reply-To: <4e998676-4975-8ac2-35a0-34416938b62e@kdbg.org>

Hi Hannes,

On Thu, 2 Sep 2021, Johannes Sixt wrote:

Show 17 quoted lines

> Am 02.09.21 um 16:18 schrieb Johannes Schindelin:
> > On Wed, 1 Sep 2021, Junio C Hamano wrote:
> >> A good goal.  There is no remaining use case where (a fictitious and
> >> properly working version of) "--preserve-merges" option cannot be
> >> replaced by "--rebase-merges", is it?  I somehow had a feeling that
> >> the other Johannes (sorry if it weren't you, j6t) had cases that the
> >> former worked better, but perhaps I am mis-remembering things.
> >
> > I think that I managed to address whatever concerns there were about the
> > `--rebase-merges` backend in the meantime.
>
> That was either my suggestion/desire to make no-rebase-cousins the
> default. That has been settled.
>
> Or my wish not to redo the merge, but to replay the first-parent
> difference. The idea never got traction, and I've long since abandoned
> my implementation of it.

Thank you for clarifying.

Yes, I remember how that idea came up, and I even tried that strategy for a couple of merging rebases of Git for Windows' branch thicket. Sadly, it did not work half as well as I had hoped.

The best idea I had back then still is in want of being implemented: sort of a "four-way merge". It is basically the same as a three-way merge, but allows for the pre-images to differ in the context (and yes, this cannot be represented using the current conflict markers). Definitely not trivial.

Show 8 quoted lines

> > To be honest, I developed one (minor) concern in the meantime... Should we
> > maybe try to be nicer to our users and keep handling the
> > `--preserve-merges` option by explicitly erroring out with the suggestion
> > to use `--rebase-merges` instead? Not everybody reads release notes, after
> > all. In fact, it is my experience that preciously few users have the time
> > to even skim release notes...
>
> A valid concern, I would think.

Good. Since you concur with my hunch, I implemented that change.

Thank you for reviewing, Dscho