Re: tests fail on windows with default git settings

Hi,

On 2024-07-07 01:26:13 -0400, Tom Lane wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
> > Do we want to support checking out with core.autocrlf?
>
> -1. It would be a constant source of breakage, and you could never
> expect that (for example) making a tarball from such a checkout
> would match anyone else's results.

WFM.

> > If we do not want to support that, ISTM we ought to raise an error somewhere?
>
> +1, if we can figure out how.

I can see two paths:

1) we prevent eol conversion, by using the right magic incantation in
.gitattributes

2) we check that some canary file is correctly encoded, e.g. during meson
configure (should suffice, this is realistically only a windows issue)

It seems that the only realistic way to achieve 1) is to remove the "text"
attribute from all files. That had me worried for a bit, thinking that might
have a larger blast radius. However, it looks like this is solely used for
line-ending conversion. The man page says:
"This attribute marks the path as a text file, which enables end-of-line conversion:"

Which sounds like it'd work well - except that it appears to behave oddly when
updating to such a change in an existing repo -

cd /tmp/;
rm -rf pg-eol;
git -c core.eol=crlf -c core.autocrlf=true clone ~/src/postgresql pg-eol;
cd pg-eol;
git config core.eol crlf; git config core.autocrlf true;
stat src/test/modules/test_json_parser/tiny.json -> 6748 bytes

cd ~/src/postgresql
stat src/test/modules/test_json_parser/tiny.json -> 6604 bytes
echo '* -text' >> .gitattributes
git commit -a -m tmp

cd /tmp/pg-eol
git pull
git st
...
nothing to commit, working tree clean
stat src/test/modules/test_json_parser/tiny.json -> 6748 bytes

I.e. the repo still is in CRLF state.

But if I reclone at that point, the line endings are in a sane state.

IIUC this is because line-ending conversion is done only during
checkout/checkin.

There are ways to get git to redo the normalization, but it's somewhat
awkward [1].

OTOH, given that the tests already fail, I assume our windows contributors
already have disabled autocrlf?

Greetings,

Andres Freund

[1] https://docs.github.com/en/get-started/getting-started-with-git/configuring-git-to-handle-line-endings#refreshing-a-repository-after-changing-line-endings