Re: [PATCH v3 2/2] tests(mingw): avoid very slow `mingw_test_cmp`

From: Taylor Blau <me@ttaylorr.com>
To: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, "René Scharfe" <l.s.r@web.de>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Johannes Schindelin" <johannes.schindelin@gmx.de>
Subject: Re: [PATCH v3 2/2] tests(mingw): avoid very slow `mingw_test_cmp`
Date: Sat, 12 Nov 2022 23:51:52 -0500	[thread overview]
Message-ID: <Y3B36HjDJhIY5jNz@nand.local> (raw)
In-Reply-To: <a7f4265ceb26c6dd9d347ef4cbef2aac7d60bf13.1668290855.git.gitgitgadget@gmail.com>

On Sat, Nov 12, 2022 at 10:07:34PM +0000, Johannes Schindelin via GitGitGadget wrote:
> From: Johannes Schindelin <johannes.schindelin@gmx.de>
>
> It is more performant to run `git diff --no-index` than running the
> `mingw_test_cmp` code with MSYS2's Bash, i.e. the Bash that Git for
> Windows uses. And a lot more readable.

This makes sense, and motivates the changes below.

> Note: Earlier attempts at fixing this involved a test helper that avoids
> the overhead of the diff machinery, in favor of implementing a behavior
> that is more in line with what `mingw_test_cmp` does now, but that
> attempt saw a lot of backlash and distractions during review and was
> therefore abandoned.

But I do not think that this paragraph adds as much as we'd like to the
historical record.

What about the original approach did you have trouble pushing forward?
Perhaps framing that as an alternative approach, along with why it
didn't ultimately get merged would be a more useful recollection of
previous attempts here.

One thing that the commit message doesn't allude to (that is covered in
the earlier discussion) is why it is important to pass
`--ignore-cr-at-eol`. I think that is worth mentioning here.

Thanks,
Taylor