bug#65609: 30.0.50; inhibit-eol-conversion breaks revert-buffer

[Andrew Scott]

It appears that inhibit-eol-conversion breaks insert-file-contents's
replace functionality when a change was made in the middle of the file
to be reverted as the file contents get duplicated in the buffer. The
issue can be reproduced on a fresh Emacs with a file named bug.el with
contents:

    ;; 1. Launch Emacs: nix run emacs-overlay#emacs-git -- bug.el -Q --load bug.el
    ;; 2. Outside of Emacs, add text in below empty line:
    ;; 3. In Emacs, revert-buffer

    (setq inhibit-eol-conversion t)

The contents of the buffer after revert-buffer:

    ;; 1. Launch Emacs: nix run emacs-overlay#emacs-git -- bug.el -Q --load bug.el
    ;; 2. Outside of Emacs, add text in below empty line:
    ;; 3. In Emacs, revert-buffer
    foo
    (setq inhibit-eol-conversion t)

    (setq inhibit-eol-conversion t)

I couldn't reproduce this on Emacs 28.2 (nixpkgs#emacs) or 29.1
(emacs-overlay#emacs-unstable).

In GNU Emacs 30.0.50 (build 1, aarch64-apple-darwin22.6.0, NS
appkit-2299.70 Version 13.5.1 (Build 22G90))
Repository revision: 09351df10a1041d58c7236484f96d6999bfe9cb0
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2299
System Description:  macOS 13.5.1

Configured using:
 'configure
 --prefix=/nix/store/37hr4bsvv94zlh8abxs2bylxn2dj0fix-emacs-git-20230826.0
 --disable-build-details --with-modules --disable-ns-self-contained
 --with-ns --with-native-compilation --with-tree-sitter'

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

Important settings:
  value of $EMACSNATIVELOADPATH: /Users/a/.cache/emacs/eln-cache
  value of $LC_COLLATE: C
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8-unix

Major mode: ELisp/d

Minor modes in effect:
  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
  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 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 ansi-osc ansi-color ring comp comp-cstr warnings icons subr-x rx
cl-seq cl-macs gv cl-extra help-mode bytecomp byte-compile vc-git
diff-mode easy-mmode vc-dispatcher cl-loaddefs cl-lib 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 touch-screen 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 multi-tty
make-network-process native-compile emacs)

Memory information:
((conses 16 153137 16869) (symbols 48 8291 0) (strings 32 26303 2093)
 (string-bytes 1 843959) (vectors 16 18856)
 (vector-slots 8 366824 13619) (floats 8 29 52) (intervals 56 16278 0)
 (buffers 992 15))