bug#53795: 27.2; unexpected column change while kbd-macro

bug#53795: 27.2; unexpected column change while kbd-macro

[awrhygty]

Evaluate the form below, I expect all lines look like "abc".
But some of the lines look like "cycaby".

(let ((buf (generate-new-buffer "tmp")))
  (switch-to-buffer buf)
  (dotimes (i 100)
    (insert (propertize "x" 'display "ab") "y\n"))
  (goto-char (point-min))
  (end-of-line)
  (execute-kbd-macro "\C-b\C-dc\C-n" 100))



In GNU Emacs 27.2 (build 1, x86_64-w64-mingw32)
 of 2021-03-26 built on CIRROCUMULUS
Repository revision: deef5efafb70f4b171265b896505b92b6eef24e6
Repository branch: HEAD
Windowing system distributor 'Microsoft Corp.', version 10.0.19043
System Description: Microsoft Windows 10 Pro (v10.0.2009.19043.1466)

Recent messages:

Configured using:
 'configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install 'CFLAGS=-O2 -static''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY W32NOTIFY ACL GNUTLS LIBXML2
HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS MODULES THREADS JSON PDUMPER LCMS2 GMP

Important settings:
  value of $LANG: JPN
  locale-coding-system: cp932

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
format-spec rfc822 mml mml-sec password-cache epa derived epg epg-config
gnus-util rmail rmail-loaddefs text-property-search time-date subr-x seq
byte-opt bytecomp byte-compile cconv mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils term/bobcat eieio-core
cl-macs gv eieio-loaddefs help-mode easymenu cl-loaddefs cl-lib
japan-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel dos-w32 ls-lisp disp-table term/w32-win w32-win
w32-vars term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame minibuffer cl-generic 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 charscript charprop case-table epa-hook
jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads w32notify w32 lcms2 multi-tty make-network-process
emacs)

Memory information:
((conses 16 53409 6986)
 (symbols 48 6621 1)
 (strings 32 18204 1977)
 (string-bytes 1 568216)
 (vectors 16 11421)
 (vector-slots 8 214687 9278)
 (floats 8 23 85)
 (intervals 56 247 57)
 (buffers 1000 12))

bug#53795: 27.2; unexpected column change while kbd-macro

[Eli Zaretskii]

> From: awrhygty@outlook.com
> Date: Sat, 05 Feb 2022 18:40:46 +0900
> 
> Evaluate the form below, I expect all lines look like "abc".
> But some of the lines look like "cycaby".
> 
> (let ((buf (generate-new-buffer "tmp")))
>   (switch-to-buffer buf)
>   (dotimes (i 100)
>     (insert (propertize "x" 'display "ab") "y\n"))
>   (goto-char (point-min))
>   (end-of-line)
>   (execute-kbd-macro "\C-b\C-dc\C-n" 100))

That's because current-column returned an incorrect value when display
strings are used.  In the "tmp" buffer, go to the first line, move
cursor to the 'y' character, and type "C-x =" -- you will see that
Emacs thinks this is column 1, not 2.

I've now fixed current-column in this case (on the master branch), so
the above snippet now behaves as expected.