Subject: Re: bug#52394: 27.2; Isearch with char folding enableddoesn’t match equivalent strings

From: Juri Linkov <[email-masked]>
Date: Sat, 11 Dec 2021 21:46:05 +0200

>> Please note that when the search string is too long for char folding,
>> then it displays the message at the end of the Isearch prompt
>> before disabling char folding:
>
> Emacs doesn’t display any message, I’ve tried catching it with
> ‘(setq debug-on-message "Too")’ but got nothing.
>
>> But the regexp have limitations when matching runs out of
>> internal stack space.  This is described in the Info node:
>>   (info "(elisp) Regexp Problems")
>
> I’ve found the Info node on [1] but not in my Emacs nor on [2].
> Could it be that both the node and the message are new features of
> versions > 27.2?

Indeed, thanks for pointing to the version number 27.2.
That message was added in 28.1.  And also
the regexp stack size was increased too in 28.1.
And the new node exists also only in 28.1.

So unless someone has an idea how to implement the search
for regexps of arbitrary lengths, this report could be closed.