Subject: bug#79134: 31.0.50; show-paren-function at end of buffer timer fails and soft-locks point

From: Jordan Ellis Coppard <[email-masked]>
Date: Thu, 31 Jul 2025 21:15:25 +0900

Hello,

Under Emacs -Q perform: C-x C-f ~/Desktop/foobar.sh

Insert the contents

#+begin_example
#!/usr/bin/env bash

sudo dnf install podman \
#+end_example

With point immediately after the \ you just typed try going backwards 
one char via C-b.

Observe the following in *Messages*

#+begin_example
Error running timer ‘show-paren-function’: (end-of-buffer)
#+end_example

Also observe that point will be "snapped" back to immediately after \ 
essentially soft-locking it. You can escape this by using M-b instead, 
C-p, C-a, etc. Anything else that moves point by more than 1 character.

/Jordan

--- diagnostic info ---

In GNU Emacs 31.0.50 (build 1, aarch64-apple-darwin23.6.0, NS
  appkit-2487.70 Version 14.7.2 (Build 23H311)) of 2025-06-21 built on
  yote.local
Repository revision: 1bc86b17768231afcf14e9df08629088dbded428
Windowing system distributor 'Apple', version 10.3.2487
System Description:  macOS 14.7.2

Configured using:
  'configure --prefix=/opt/local --disable-silent-rules --without-dbus
  --without-gconf --without-libotf --without-m17n-flt --with-libgmp
  --with-gnutls --with-xml2 --with-modules --with-sqlite3 --with-webp
  --with-native-compilation=aot --infodir /opt/local/share/info/emacs
  --disable-gc-mark-trace --with-ns --with-lcms2 --without-harfbuzz
  --without-imagemagick --without-xaw3d --with-rsvg --with-tree-sitter
  'CFLAGS=-pipe -O2 -march=native -mtune=native -Wno-attributes
  -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk -arch
  arm64' 'CPPFLAGS=-I/opt/local/include
  -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk'
  'LDFLAGS=-L/opt/local/lib -Wl,-headerpad_max_install_names -Wl,-no_pie
  -Wl,-rpath /opt/local/lib/gcc14 -Wl,-rpath /opt/local/lib
  -Wl,-syslibroot,/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk
  -arch arm64''

Configured features:
ACL GIF GLIB GMP GNUTLS JPEG LCMS2 LIBXML2 MODULES NATIVE_COMP NOTIFY
KQUEUE NS PDUMPER PNG RSVG SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
TREE_SITTER WEBP XIM ZLIB

Important settings:
   value of $LC_ALL: en_US.UTF-8
   value of $LC_CTYPE: en_US.UTF-8
   value of $LANG: en_AU.UTF-8
   locale-coding-system: utf-8-unix

Major mode: Shell-script

Minor modes in effect:
   sh-electric-here-document-mode: t
   tooltip-mode: t
   global-eldoc-mode: t
   eldoc-mode: t
   show-paren-mode: t
   electric-indent-mode: t
   mouse-wheel-mode: t
   tool-bar-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   minibuffer-regexp-mode: t
   line-number-mode: t
   indent-tabs-mode: t
   transient-mark-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug lisp-mnt message mailcap yank-media puny
dired dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg
rfc6068 epg-config gnus-util time-date mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils compile
text-property-search comint subr-x ansi-osc ansi-color ring comp-run
bytecomp byte-compile comp-common sh-script rx smie treesit cl-loaddefs
cl-lib executable rmc iso-transl tooltip cconv eldoc paren electric
uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel
term/ns-win ns-win ucs-normalize mule-util term/common-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow
isearch easymenu timer select scroll-bar mouse jit-lock font-lock syntax
font-core term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads kqueue cocoa ns lcms2
multi-tty make-network-process tty-child-frames native-compile emacs)

Memory information:
((conses 16 77413 10074) (symbols 48 7465 0) (strings 32 20717 2006)
  (string-bytes 1 723233) (vectors 16 12242)
  (vector-slots 8 184182 12946) (floats 8 25 10) (intervals 56 304 0)
  (buffers 1064 12))