bug#21278: char-fold isearch: space and newline still broken

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Eli Zaretskii <eliz@gnu.org>,  Stefan Monnier
>  <monnier@iro.umontreal.ca>,  21278@debbugs.gnu.org,  rms@gnu.org,
>   bruce.connor.am@gmail.com
> Date: Fri, 10 Sep 2021 12:28:20 +0200
> 
> > Seconded.  Everyone who wants to match a newline,
> > still needs to customize search-whitespace-regexp
> > to include \n, e.g. "\\(?:\\s-\\|\n\\)+", so an explicit
> > list of characters would be more deterministic.
> 
> It seems like everybody agrees that the old value was confusing, so I've
> now changed it to [ \t] in Emacs 28.

Shouldn't it be [ \t]+ instead?