bug#45999: 28.0.50; repeat does not work when saving files modified outside emacs

bug#45999: 28.0.50; repeat does not work when saving files modified outside emacs

[Gabriel do Nascimento Ribeiro]

1) Normal case:
1.1) Run 'emacs -q'
1.2) Open a file with 'C-x C-f'
1.3) Make some modification without saving the buffer
1.4) Save the buffer with 'C-x C-s'
1.5) Repeat last last command with 'C-x z'. You will see the message '(no
changes need to be saved)' indicating that the 'save-buffer' command was
repeated.

2) Problematic case:
2.1) Run 'emacs -q'
2.2) Open a file with 'C-x C-f'
2.3) Make some modification without saving the buffer
2.4) Edit the same file outside emacs (with another text editor or with
shell command 'touch')
2.5) Save the buffer with 'C-x C-s'. You will see the message
'<filename> has changed since visited or saved. Save anyway ?'. Type
'yes'
2.6)  Repeat last last command with 'C-x z'. You will see the message
'Repeating (find-file <path> t)' indicating that the last command before
'save-buffer' was repeated, which in this case was 'find-file' command
with 'C-x C-f'. It's possible to test with some other command before saving
the buffer to see what happens with the '(repeat)' command.

In GNU Emacs 28.0.50 (build 39, x86_64-pc-linux-gnu, GTK+ Version 3.24.23, cairo version 1.16.0)
 of 2021-01-16 built on precision5540
Repository revision: 25e1b732947bcba51e457a7168eba6608fb666c0
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12009000
System Description: Ubuntu 20.10

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

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

Major mode: Browse Server

Minor modes in effect:
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  global-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
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
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url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util url-parse url-vars mailcap gnus-group gnus-undo
gnus-start gnus-dbus dbus xml gnus-cloud nnimap nnmail mail-source utf7
netrc nnoo parse-time gnus-spec gnus-int gnus-range message rmc puny
rfc822 mml mml-sec epa derived epg epg-config mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader gnus-win
gnus nnheader gnus-util rmail rmail-loaddefs auth-source cl-seq eieio
eieio-core cl-macs eieio-loaddefs password-cache json map rfc2047
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wid-edit ol-docview doc-view image-mode exif dired dired-loaddefs
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prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
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sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote threads dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting cairo
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 295807 45058)
 (symbols 48 23424 1)
 (strings 32 114515 4556)
 (string-bytes 1 3691174)
 (vectors 16 37971)
 (vector-slots 8 463088 27462)
 (floats 8 266 124)
 (intervals 56 70122 0)
 (buffers 984 24))

bug#45999: 28.0.50; repeat does not work when saving files modified outside emacs

[Lars Ingebrigtsen]

Gabriel do Nascimento Ribeiro <gabriel376@hotmail.com> writes:

> 2) Problematic case:
> 2.1) Run 'emacs -q'
> 2.2) Open a file with 'C-x C-f'
> 2.3) Make some modification without saving the buffer
> 2.4) Edit the same file outside emacs (with another text editor or with
> shell command 'touch')
> 2.5) Save the buffer with 'C-x C-s'. You will see the message
> '<filename> has changed since visited or saved. Save anyway ?'. Type
> 'yes'
> 2.6)  Repeat last last command with 'C-x z'. You will see the message
> 'Repeating (find-file <path> t)' indicating that the last command before
> 'save-buffer' was repeated, which in this case was 'find-file' command
> with 'C-x C-f'. It's possible to test with some other command before saving
> the buffer to see what happens with the '(repeat)' command.

I can't reproduce this exactly -- in Emacs 29, `C-x z' executes
`exit-minibuffer', since that's the value of `last-repeatable-command'
after typing "yes".  (Most likely due to yes-or-no-p being reimplemented
as non-modal.)

I'm not at all familiar with how `last-repeatable-command' is supposed
to work -- it's just set from command_loop_1, and there's no blocklist
of commands or anything, so it seems like any commands that prompts with
yes-or-no-p/completing-read/etc aren't repeatable (now).

(defun foo ()
  (interactive)
  (yes-or-no-p "Foo")
  (message "%s" last-repeatable-command))

and examine 

last-repeatable-command

I guess a way to fix this would be to introduce a blocklist (containing
minibuffer-exit/self-insert-command/etc/etc), but I'm not sure how much
etc this would be.  Or perhaps there's a different way around this.

Any opinions?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#45999: 28.0.50; repeat does not work when saving files modified outside emacs

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> I guess a way to fix this would be to introduce a blocklist (containing
> minibuffer-exit/self-insert-command/etc/etc), but I'm not sure how much
> etc this would be.  Or perhaps there's a different way around this.

I tried various approaches, but none seemed to work in a satisfactory
way -- adding a variable to inhibit recording last-repeatable-command
didn't work well, because of how it's set from command_loop_1, and a
blocklist just seemed odd.

But the main problem here is that yes-or-no-p now overwrites
last-repeatable-command with exit-minibuffer, and that's a regression at
least, so I've fixed this specific problem.  But I'm still not sure
whether it should be fixed in a more general way, and perhaps a
blocklist is the way to go, anyway...  but the reason I didn't do that
is because self-insert-command would have to be on that list for
yes-or-no-p to not override `repeat', and that's a behavioural change.

So I went with the easy fix.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no