bug#79301: fold-spaces test failure

Bruno Haible via GNU coreutils Bug Reports <[email protected]>
writes:

> Today's CI reports a test failure
>   FAIL: tests/fold/fold-spaces
> on several systems:
>   - Alpine Linux,
>   - macOS 13..15,
>   - FreeBSD 14.
>
> Here are the relevant parts of the log files.

Thanks.

On Alpine this is because iswblank in UTF-8 locales is the same as
isblank in the C locale. This means it only returns 1 for U+0009 TAB and
U+0020 SPACE. I haven't looked at the others, but assume the situation
is similar.

I am thinking of fixing this in Gnulib since I think the proper behavior
of iswblank in a UTF-8 locale is to return 1 for U+2002 EN SPACE and
U+2003 EM SPACE. This is because they are just altering the size of the
SPACE character [1] [2].

Collin

[1] https://en.wikipedia.org/wiki/En_(typography)
[2] https://en.wikipedia.org/wiki/Em_(typography)