bug#81612: 32.0.50; setting marks in dired-hidden directories creates garbled output

Reproduce in "emacs -Q":
1. C-x C-f /etc RET to open a folder in dired
2. Press $ to hide the folder. It contracts everything into a line
3. Press m to mark the files at point

Result: screen text is garbled. You see a long line like
  /etc:*  drwxr-xr-x 222 root  root      20480 Aug 12 17:39 .*
drwxr-xr-x  24 root  root       4096 Aug  5 01:49 ..*  -rw-r--r--   1
root  root      12823 Dec 23  2024 a2ps.cfg*  -rw-r--r--   1 root
root       2502 Dec 23  2024 a2ps-site.cfg*  drwxr-xr-x   3 root  root
      4096 Aug  5 17:52 acpi*  -rw-r--r--   1 root  root       3981
May  7  2025 adduser.conf*  -rw-r--r--   1 root  root       2981 Feb
28  2023 adduser.conf.update-old*  -rw-r--r--   1 root  root
46 […]


I think it's because dired-get-filename does this unhide+hide:
    (when hidden
      (dired-unhide-subdir))
    (save-excursion
      (if (setq p1 (dired-move-to-filename (not no-error-if-not-filep)))
 (setq p2 (dired-move-to-end-of-filename no-error-if-not-filep))))
    (when hidden
      (dired-hide-subdir 1))


But dired-hide-subdir says it may move the point:
(defun dired-hide-subdir (arg)
  "Hide or unhide the current subdirectory and move to next directory. […]"
[…]
(goto-char (cdr elt))
[…]
)


With this it works:
    (when hidden
      (save-excursion (dired-hide-subdir 1)))

Patch:


diff --git a/lisp/dired.el b/lisp/dired.el
index ac12bf42565..019cf9d8fc4 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -3297,7 +3297,7 @@ dired-get-filename
       (if (setq p1 (dired-move-to-filename (not no-error-if-not-filep)))
          (setq p2 (dired-move-to-end-of-filename no-error-if-not-filep))))
     (when hidden
-      (dired-hide-subdir 1))
+      (save-excursion (dired-hide-subdir 1)))
     ;; nil if no file on this line, but no-error-if-not-filep is t:
     (if (setq file (and p1 p2 (buffer-substring p1 p2)))
        (progn








In GNU Emacs 32.0.50 (build 7, x86_64-pc-linux-gnu) of 2026-08-12 built on sonn
Repository revision: c693e12efa3fecc72cbc5a53047d5a360854ded2
Repository branch: master
System Description: Devuan GNU/Linux 6 (excalibur)

Configured using:
 'configure --prefix=/opt/dc/emacs/ --without-lcms2
--without-libsystemd --without-dbus
 --without-sound --with-mailutils --with-native-compilation=yes
--without-modules
 --with-x-toolkit=no --without-xim --without-imagemagick --without-xft
--without-harfbuzz
 --without-libotf --without-xwidgets --without-xpm --with-tiff=no
--without-tiff --without-jpeg
 --without-gif --without-png --without-webp --without-rsvg
--without-cairo --without-x
 --enable-checking=yes,glyphs 'CFLAGS=-g3 -O2''

Configured features:
GMP GNUTLS LIBXML2 NATIVE_COMP NOTIFY INOTIFY PDUMPER SECCOMP SQLITE3
THREADS XIM ZLIB

Important settings:
  value of $LANG: en_US.UTF-8

  value of $XMODIFIERS: @im=SCIM
  locale-coding-system: utf-8-unix