Re: Texinfo 7.0.93 pretest available

[Eli Zaretskii]

> From: Bruno Haible <bruno@clisp.org>
> Cc: gavinsmith0123@gmail.com, bug-texinfo@gnu.org
> Date: Mon, 09 Oct 2023 19:18:25 +0200
> 
> Eli Zaretskii wrote:
> > > I just tried it now: On Linux (Ubuntu 22.04), in a de_DE.UTF-8 locale,
> 
> Oops, typo: What I tested was the de_DE.ISO-8859-1 locale:
> $ export LC_ALL=de_DE.ISO-8859-1

So wcwidth in ISO-8895-1 locale returns 1 for U+0237?  Even though
U+0237 cannot be encoded in ISO-8895-1?  And iswprint returns non-zero
for it in that locale?

Or does the Texinfo test suite forces the locale to something UTF-8?

> > Since U+0237 is not printable in my locale (it isn't supported by the
> > system codepage), the value -1 is correct.  Am I missing something?
> 
> True. But why don't we see the same test failure on glibc and on FreeBSD
> systems, then, in a locale with ISO-8859-1 encoding?

Good question.  Maybe they interpret the Posix standards differently
(if the locale is not forced by the test suite).

> > > This "simpler approximation" would not return a good result when wc
> > > is a control character (such as CR, LF, TAB, or such). It is important
> > > that the caller of wcwidth() or wcswidth() is able to recognize that
> > > the string as a whole does not have a definite width.
> > 
> > It is still better than returning -1, don't you agree?
> 
> No, I don't agree. Returning -1 tells the caller "watch out, you cannot
> assume anything about printed outline of this string".

I meant "better for Texinfo when it generates Info manuals", not in
general.

> > But for some reason you completely ignored my more general comment
> > about what Texinfo needs from wcwidth.
> 
> That's because I am not familiar with the Texinfo code. I don't know
> whether and where Texinfo calls wcwidth(), and I don't know with which
> expectations it does so.

It calls wcwidth to know how many columns a character will take, in
order to fill lines, when it generates manuals in the Info format.