Re: [PATCH] pull: conflict hint pull.rebase suggestion should offer "merges" vs "true"

From: Tao Klerks <tao@klerks.biz>
Date: Feb 17, 2023, 11:15 UTC
Message-ID: <CAPMMpoj0Ts=c=Wq1eghjJ75HVyy5ZyKjL3o9=AB8SDb5Wf99mw@mail.gmail.com>
In-Reply-To: <CAMMLpeTQ1RpsvwRdZ0G3wdvH1+LXE5tw=7Cs6Q+HxMcRU0qj5Q@mail.gmail.com>

On Fri, Feb 17, 2023 at 4:15 AM Alex Henrie <alexhenrie24@gmail.com> wrote:

>
> I would be OK with the proposed patch if it were part
> of a larger effort to make --rebase-merges the default behavior of
> `git rebase`.

Heh, what would it take to convince you there is such an effort? :) - sparse and minor as my contributions are, I certainly believe that is a "natural" effort that I will do what I can to support.

> That seems like an achievable goal, and I don't think it
> would take multiple years, maybe one year at the most.

My estimate is based on the observation that there are still, several years after --rebase-merges was introduced, git GUIs that don't handle it right - eg Jetbrains IDEA: https://youtrack.jetbrains.com/issue/IDEA-232160/Rebase-merges-is-not-properly-supported

This kind of functionality change should be slow, not because it's a huge amount of work, but more because it takes time for the entire ecosystem to adapt. Git releases basically-monthly, but many of the systems that users use git with release far less often; similarly, it's helpful to users who use a mix of current and older systems (I'm looking at you, CentOS 7) for the introduction and recommendation of a behavior change to come *long* before its defaulting.

Show 6 quoted lines

> The process
> would look something like this:
>
> 1. Add a --no-rebase-merges option to `git rebase`.
>
> 2. Add a rebase.merges config option.

Yes and yes! I alluded to this in https://lore.kernel.org/git/CAPMMpoj6E-85a59EaHD2aR_oKA=_u78qRV+wp8mqXkR39KctmA@mail.gmail.com/ but didn't feel I'd likely to make a solid change along these lines.

Show 7 quoted lines

>
> 3. Add a warning to `git rebase` that appears if rebase.merges is
> unset and neither --rebase-merges nor --no-rebase-merges is given. The
> warning would advise the user that the default behavior of `git
> rebase` will change in a future release and suggest setting
> rebase.merges=no-rebase-cousins to get the new behavior now.
>

Makes sense to me!

> 4. Change the `git pull` advice to recommend --rebase=merges and
> pull.rebase=merges.
>

I'm not sure why this would be step 4 - I would (and did try to) make it step 1 :)

> 5. Wait a couple of releases.
>

As I noted above, I believe it should be far more than a couple.

Show 6 quoted lines

> 6. Change the default behavior of `git rebase` to `git rebase
> --rebase-merges` and the default behavior of `git pull --rebase` to
> `git pull --rebase=merges`. At the same time, remove the warning from
> `git rebase`. The old `git pull` behavior would still be available as
> `git pull --rebase=true`.
>

Makes sense to me!

Show 6 quoted lines

> 7. Change the `git pull` advice to recommend the short and simple
> --rebase option again (leaving the recommendation of
> pull.rebase=merges for the config option).
>
> Does that sound reasonable? I think I could lend a hand with steps 1-3.
>

I'm sold, except insofar as I think the right approach is to move step 4 to be the first :)