bug#20871: 25.0.50; fill-single-char-nobreak-p does not recognize a single-letter word when it is preceded by an open paren

[Eli Zaretskii]

> From: Michał Nazarewicz <mina86@mina86.com>
> Date: Mon, 19 Aug 2019 16:36:15 +0100
> Cc: Mattias Engdegård <mattiase@acm.org>, mbork@mbork.pl, 
>       20871@debbugs.gnu.org
> 
> > If both functions attempt to produce the same behavior, then yes, we
> > need only one.  But then wouldn't we need a second one, to produce the
> > behavior expected, say, in US English?
> 
> The expected behaviour for US English is achieved by not using the
> function at all.

If that's true (and I'm not an expert to say it is), then all we need
is a suitable change to the doc string of fill-nobreak-predicate,
since currently it says nothing about what should be done for English.

> In that case I could see a potential reason to have multiple
> functions:
> - ‘fill-polish-nobreak-p’ – don’t break after a, e, i, o, u, w or z;
> - ‘fill-czech-nobreak-p’ – don’t break after a, i, k, o, s, u, v or z;
>   and
> – ‘fill-single-char-nobreak-p’ – don’t break after any single letter
>   word.

Don't forget fill-french-nobreak-p.