Re: `--rebase-merges' still failing badly

[Junio C Hamano <gitster@pobox.com>]

Michael Witten <mfwitten@gmail.com> writes:

> On Wed, 10 Oct 2018 14:43:46 +0900, Junio wrote:
>
>> We haven't seen  much complaints and breakages  reported against the
>> two big "rewrite in C" topics  around "rebase"; perhaps it is a good
>> time to merge  them to 'next' soonish  to cook them for  a few weeks
>> before moving them to 'master'?
>
> In my opinion, the `--rebase-merges' feature has been broken since the
> beginning, and the builtin version should  be fixed before it is moved
> ahead.

I'll omit the remainder of the message not because I disagree with
your suggested improvements to "rebase-merges" (that conversation
should happen primarily with Dscho), but because I need to react to
the above three lines.

If "rebase-merges" has been broken since the beginning, as long as
the "rewrite in C" topics around "rebase" do not make it even worse,
I do not think it is a good move to block the topics moving forward.
If the feature were so broken that it is not practically useful,
then people wouldn't be using it in the versions of Git before the
rewrite, so it won't harm anybody if the same feature in the rewritten
version is equally (or even more severely) broken, as long as the
other parts of the feature works at least equally well compared to
the older version.

We are not in the business of hostage taking.

What *should* block the rewrited version is a regression,
i.e. something that used to work well no longer works or works
differently in such a way that established workflows need to be
adjusted.

In any case, suggestions to improve "rebase-merges" is a very much
welcome thing to be discussed on the list, so thanks for raising the
issue.  What I wanted to say is that I do not think that is a reason
to keep "rewrite in C" waiting in 'pu'.