bug#58992: 28.2; "lax space matching" no longer works

[Eli Zaretskii]

> Date: Thu, 03 Nov 2022 18:11:43 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: Eli Zaretskii <eliz@gnu.org>, 58992@debbugs.gnu.org
> 
> emacs -Q
> ab RET cd RET ab SPC cd
> M-<
> C-s b SPC c ;; only one match
> C-x C-s foo RET
> M-<
> C-s b SPC c ;; two matches in Emacs 27, one match in Emacs 28
> 
> Hmm...

Did you look at the value of search-whitespace-regexp in both cases?