Subject: bug#52356: 27.2; Isearch prompt changes unexpectedly with char folding enabled

From: Andrea Greselin <[email-masked]>
Date: Tue, 7 Dec 2021 19:38:15 +0100

Hello,
when I use Isearch with char folding enabled, the prompt changes very
briefly at every character I type in. The actual prompt depends on the
values of ‘lazy-count-*-format’ and ‘search-default-mode’ (if they all
have their default value the prompt is ‘Pending char-fold I-search:…’;
with the settings described below it’s just ‘I-search: …’, and it
changes briefly to ‘Pending I-search: …’).

Steps to reproduce:
-------------------

Launch ‘Emacs -Q’, evaluate these forms

    (setq isearch-lazy-count t)
    (setq lazy-count-prefix-format nil
          lazy-count-suffix-format " [%s/%s]")
    (setq-local search-default-mode 'char-fold-to-regexp)
    (electric-quote-local-mode)

and Isearch for something.

All the best,
Andrea

In GNU Emacs 27.2 (build 1, x86_64-redhat-linux-gnu, GTK+ Version 3.24.30,
cairo version 1.17.4)
 of 2021-08-07 built on buildvm-x86-29.iad2.fedoraproject.org
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: Fedora 34 (Workstation Edition)

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list... [5 times]

Configured using:
 'configure --build=x86_64-redhat-linux-gnu
 --host=x86_64-redhat-linux-gnu --program-prefix=
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Configured features:
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Important settings:
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Major mode: Lisp Interaction

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Load-path shadows:
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Memory information:
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