Re: [PATCH v4 2/2] tests(mingw): avoid very slow `mingw_test_cmp`

From: Taylor Blau <me@ttaylorr.com>
To: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: "Taylor Blau" <me@ttaylorr.com>,
	"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>,
	git@vger.kernel.org, "René Scharfe" <l.s.r@web.de>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Subject: Re: [PATCH v4 2/2] tests(mingw): avoid very slow `mingw_test_cmp`
Date: Sun, 20 Nov 2022 19:07:53 -0500	[thread overview]
Message-ID: <Y3rBWUidFe6SVmWI@nand.local> (raw)
In-Reply-To: <q39q9rr7-or29-5510-5177-2s92n8qs2540@tzk.qr>

On Mon, Nov 21, 2022 at 12:36:25AM +0100, Johannes Schindelin wrote:
> I am referring to the fact that Git for Windows has run with a very
> different solution for this problem, for years, yet it was rejected upon
> upstreaming, and had to be replaced by a completely different workaround.
>
> It's not just a simple "earlier round of review" at all that is the issue
> I am describing.

Right. Having read the earlier thread myself, I am familiar with the
context. So I'm not trying to dismiss it as just another round of
review, but instead try to steer the commit message in a more
constructive direction.

> It is a very real concern of future readers who know what patches are
> currently in Git for Windows and who all of a sudden do not find the `git
> test-tool cmp` code anymore in Git for Windows and then see that `git diff
> --no-index` is used and naturally want to know what the heck happened.
>
> This is context relevant to understand why the particular approach
> implemented in the patch was chosen and another one was discarded (when
> that other approach has served Git for Windows very well for several
> years), for which the commit message is precisely the appropriate place. I
> am quite lost trying to understand why I am asked to remove said context,
> leaving future readers puzzled e.g. in the case that it should turn out to
> have been a terrible idea to use the quite complex diff machinery for as
> simple a task as `test_cmp`. It sounds to me like I am asked to make my
> contribution worse ("worsimprove" is the term I recently learned to
> describe this) instead of helping me to improve it.

No. I am not suggesting you remove context at all. But what I am saying
is that describing the last attempt at upstreaming by saying it "saw a
lot of backlash and distractions during review and was therefore
abandoned" is not helpful.

If it saw backlash and distraction: why? What about the approach caused
backlash? Describing that thing as an alternative approach and
explaining concretely why it was disliked is the sort of context that I
think we should aim for in our commit messages.

But characterizing the review outright as full of backlash and
distractions is not helpful to future readers, and it is not a kind way
to treat others on the list who may have participated in that review.

> The advice you provided directly contradicts what is written in
> https://git-scm.com/docs/SubmittingPatches#describe-changes, after all
> (ignore the funny grammar for now unless you want to add a tangent to this
> already long thread):
>
> 	The body should provide a meaningful commit message, which:
>
> 	    [...]
>
> 	    3. alternate solutions considered but discarded, if any.

I am saying that, as written, the commit message does not explain what
the alternative approaches were in great detail.

Thanks,
Taylor