bug#18150: 24.3.92; Uppercase umlauts and case-fold-search t

[Eli Zaretskii]

> From: Marcin Borkowski <mbork@mbork.pl>
> Date: Tue, 16 Feb 2016 15:53:41 +0100
> Cc: 18150@debbugs.gnu.org
> 
> Confirmed on emacs -Q (GNU Emacs 25.1.50.2, commit 4ccd268).
> 
> Best,
> mb
> 
> On 2014-07-30, at 18:11, Michael Heerdegen <michael_heerdegen@web.de> wrote:
> 
> > Hello,
> >
> >
> > sorry if this is just a unibyte/multibyte thing I don't understand, but
> > it makes no sense to me:
> >
> >   (let ((str "École")
> >         (case-fold-search t))
> >     (when (string-match "[[:upper:]]" str)
> >       (match-string 0 str)))
> >
> > ==> "c"
> >
> > However,
> >
> >   (let ((str "École")
> >         (case-fold-search nil))
> >     (when (string-match "[[:upper:]]" str)
> >       (match-string 0 str)))
> >
> > ==> "É"
> >
> > I would expect "É" in both examples.

What do we expect the result to be in the variant below?

   (let ((str "ecole")
         (case-fold-search t))
     (when (string-match "[[:upper:]]" str)
       (match-string 0 str)))