Subject: bug#72556: closed (Re: bug#72556: 29.1.90; vc-diff does not undo hunk in end of source file)

From: [email-masked] (GNU bug Tracking System)
Date: Sat, 15 Mar 2025 03:11:02 +0000

Your bug report

#72556: 29.1.90; vc-diff does not undo hunk in end of source file

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
72556: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=72556
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#72556: 29.1.90; vc-diff does not undo hunk in end of source file
From: Dmitry Gutov <[email-masked]>
To: Tomas Nordin <[email-masked]>, Juri Linkov <[email-masked]>
Cc: Eli Zaretskii <[email-masked]>, [email-masked]
Date: Sat, 15 Mar 2025 05:10:15 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

Version 31.1

On 13/03/2025 00:19, Tomas Nordin wrote:

> Here it is, on top of todays master

Thank you, I've pushed the combined patch to the master branch:

https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=4980287e081d3efd29f64973938ca2a0575f521e

Any further improvements to the diff-mode tests would be welcome too - 
such as similar test case(s) for deletion hunks and/or extracting the 
common part of the new test cases into a macro.

This report meanwhile seems resolved.

Subject: 29.1.90; vc-diff does not undo hunk in end of source file
From: Tomas Nordin <[email-masked]>
To: [email-masked]
Date: Sat, 10 Aug 2024 12:11:08 +0000
List-Id: <debbugs-submit.debbugs.gnu.org>

Hello Emacs

I have got used to the diff-mode feature of undoing hunks. I have
noticed that if the diff hunk is an addition in the end of the source
file, I dont get the expected question if I want to undo the hunk.
Instead, the hunk is applied again.

My example is with a git repo, some edits made (and saved to disk) in a
file, and hitting C-x v = to view the diff. Move to one of the hunks.
One can now diff-apply-hunk to reverse the hunk. But if that hunk is the
last thing in the source file, the hunk is applied (again). This is not
what I expect.

To reproduce:

$ mkdir apply
$ cd apply
$ echo "first line of code" > example.file
$ git init
$ git add .
$ git commit -m 'init'
$ echo "last line of code" >> example.file
$ emacs -Q example.file

C-x v =
n
C-c C-a

The hunk is applied in the source buffer.

In GNU Emacs 29.1.90 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.38, cairo version 1.16.0) of 2023-11-18 built on fliptop2
Repository revision: d9e43f2197fa1d5ade1d483b15cc50c6d705b969
Repository branch: emacs-29
Windowing system distributor 'The X.Org Foundation', version 11.0.12101007
System Description: Debian GNU/Linux 12 (bookworm)

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY
INOTIFY PDUMPER PNG RSVG SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS
WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

Important settings:
  value of $LC_MONETARY: sv_SE.UTF-8
  value of $LC_NUMERIC: sv_SE.UTF-8
  value of $LC_TIME: sv_SE.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
  tooltip-mode: t
  global-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 text-property-search mm-decode mm-bodies mm-encode
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rfc2045 ietf-drums mm-util mail-prsvr mail-utils time-date subr-x
smerge-mode diff vc vc-git diff-mode easy-mmode vc-dispatcher
cl-loaddefs cl-lib rmc iso-transl tooltip cconv eldoc paren electric
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emacs)

Memory information:
((conses 16 44032 13907)
 (symbols 48 5959 0)
 (strings 32 16246 1269)
 (string-bytes 1 466537)
 (vectors 16 10894)
 (vector-slots 8 165303 14637)
 (floats 8 28 20)
 (intervals 56 226 0)
 (buffers 976 13))