bug#74637: [PATCH] Make view-read-only behave like view-file

["Björn Bidar via Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

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Tags: patch


Make view-mode behave like when called in view-file when entered because
`view-read-only' is true on a file which is not writable.
The change makes the view-read-only behave better on files which are
not writable. 
Now it makes Emacs behave more like less on these files.



In GNU Emacs 31.0.50 (build 1, x86_64-suse-linux-gnu, GTK+ Version
3.24.43, cairo version 1.18.2)
Repository revision: eee0ed8442aa78320a3e578ab290df145fb49624
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101014
System Description: openSUSE Tumbleweed

Configured using:
 'configure --disable-build-details --without-pop --with-mailutils
 --without-hesiod --with-gameuser=:games --with-kerberos
 --with-kerberos5 --with-file-notification=inotify --with-modules
 --enable-autodepend --enable-link-time-optimization --prefix=/usr
 --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share
 --localstatedir=/var --sharedstatedir=/var/lib
 --libexecdir=/usr/libexec --with-file-notification=yes
 --libdir=/usr/lib64 --with-native-compilation=aot
 --enable-locallisppath=/usr/share/emacs/31.0.50/site-lisp:/usr/share/emacs/site-lisp
 --with-x --with-xim --with-sound --with-xpm --with-jpeg --with-tiff
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From d77d0880871061820b1cdf61f1d74f2a7e5224aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Bidar?= <bjorn.bidar@thaodan.de>
Date: Sun, 1 Dec 2024 22:22:24 +0200
Subject: [PATCH] Make view-read-only behave like view-file

Make view-mode also behave like less when entered through the
view-read-only option similarly as done in in
'1997-06-14 "Make view mode more similar to `less'' (ab7782fc244).
* lisp/files.el (after-find-file):
When opening a file which is read only and `view-read-only' is true
leave view-mode with `kill-buffer-if-not-modified'.
* lisp/view.el (view-mode): Document new behavior.
---
 lisp/files.el | 2 +-
 lisp/view.el  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lisp/files.el b/lisp/files.el
index a65bc4a4ea2..2f062b45daf 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -2874,7 +2874,7 @@ after-find-file
     (when (and buffer-read-only
 	       view-read-only
 	       (not (eq (get major-mode 'mode-class) 'special)))
-      (view-mode-enter))
+      (view-mode-enter nil 'kill-buffer-if-not-modified))
     (run-hooks 'find-file-hook)))
 
 (define-obsolete-function-alias 'report-errors 'with-demoted-errors "25.1")
diff --git a/lisp/view.el b/lisp/view.el
index 2ac7479739f..422d8a1f537 100644
--- a/lisp/view.el
+++ b/lisp/view.el
@@ -416,7 +416,7 @@ view-mode
 The effect of \\[View-leave], \\[View-quit] and \\[View-kill-and-leave] depends on how view-mode was entered.  If it was
 entered by view-file, view-file-other-window, view-file-other-frame, or
 \\[dired-view-file] \(\\[view-file], \\[view-file-other-window],
-\\[view-file-other-frame], or the Dired mode v command),
+\\[view-file-other-frame], `view-read-only', or the Dired mode v command),
 then \\[View-quit] will try to kill the current buffer.
 If view-mode was entered from another buffer, by \\[view-buffer],
 \\[view-buffer-other-window], \\[view-buffer-other frame], \\[view-file],
-- 
2.45.2