GNU bug report logs - #79551
[PATCH] Improve undo behavior in Rcirc

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Alcor <alcor <at> tilde.club>
To: bug-gnu-emacs <at> gnu.org
Subject: [PATCH] Improve undo behavior in Rcirc
Date: Wed, 01 Oct 2025 20:36:58 +0200

[Message part 1 (text/plain, inline)]

Tags: patch

Hello,

The attached minimal patch improves the undo behavior in Rcirc by
restricting changes to `buffer-undo-list' in such a way that Rcirc's own
display routines no longer affect it.

It does so by binding `buffer-undo-list' to t within Rcirc's own display
procedures. Additionally, the undo offsets within the `buffer-undo-list'
are also shifted accordingly whenever Rcirc inserts text before the
prompt (such as when receiving messages).

The patch is fairly compact and straightforward. Please note that the
new procedure `rcirc-update-undo-list' is a renamed verbatim copy of
`erc-update-undo-list' from lisp/erc/erc.el.

Cheers,
-A

In GNU Emacs 30.2 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.41,
 cairo version 1.18.0) of 2025-09-22 built on lcy02-amd64-009
Repository revision: ff7d3f02b943af29afb1c68a2b31f88441dee928
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12302006
System Description: Ubuntu 24.04.3 LTS

Configured using:
 'configure --prefix=/snap/emacs/current/usr --with-x-toolkit=gtk3
 --without-xaw3d --with-modules --with-cairo
 --with-native-compilation=aot --without-pgtk --with-xinput2
 --with-tree-sitter 'CFLAGS=-isystem
 /build/emacs/parts/emacs/install/usr/include -isystem
 /build/emacs/parts/emacs/install/usr/include/x86_64-linux-gnu -isystem
 /build/emacs/stage/usr/include -O2' 'CPPFLAGS=-isystem
 /build/emacs/parts/emacs/install/usr/include -isystem
 /build/emacs/parts/emacs/install/usr/include/x86_64-linux-gnu -isystem
 /build/emacs/stage/usr/include'
 'LDFLAGS=-L/build/emacs/parts/emacs/install/lib
 -L/build/emacs/parts/emacs/install/usr/lib
 -L/build/emacs/parts/emacs/install/lib/x86_64-linux-gnu
 -L/build/emacs/parts/emacs/install/usr/lib/x86_64-linux-gnu
 -L/build/emacs/stage/usr/lib''

[0001-Improve-undo-behavior-in-Rcirc.patch (text/patch, attachment)]

Message #8 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Philip Kaludercic <philipk <at> posteo.net>
To: Alcor via "Bug reports for GNU Emacs, the Swiss army knife of text
 editors" <bug-gnu-emacs <at> gnu.org>
Cc: 79551 <at> debbugs.gnu.org, Alcor <alcor <at> tilde.club>
Subject: Re: bug#79551: [PATCH] Improve undo behavior in Rcirc
Date: Fri, 10 Oct 2025 21:32:12 +0000

Alcor via "Bug reports for GNU Emacs, the Swiss army knife of text
editors" <bug-gnu-emacs <at> gnu.org> writes:

> Tags: patch
>
> Hello,
>
> The attached minimal patch improves the undo behavior in Rcirc by
> restricting changes to `buffer-undo-list' in such a way that Rcirc's own
> display routines no longer affect it.
>
> It does so by binding `buffer-undo-list' to t within Rcirc's own display
> procedures. Additionally, the undo offsets within the `buffer-undo-list'
> are also shifted accordingly whenever Rcirc inserts text before the
> prompt (such as when receiving messages).
>
> The patch is fairly compact and straightforward. Please note that the
> new procedure `rcirc-update-undo-list' is a renamed verbatim copy of
> `erc-update-undo-list' from lisp/erc/erc.el.
>
> Cheers,
> -A
>
> In GNU Emacs 30.2 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.41,
>  cairo version 1.18.0) of 2025-09-22 built on lcy02-amd64-009
> Repository revision: ff7d3f02b943af29afb1c68a2b31f88441dee928
> Repository branch: master
> Windowing system distributor 'The X.Org Foundation', version 11.0.12302006
> System Description: Ubuntu 24.04.3 LTS
>
> Configured using:
>  'configure --prefix=/snap/emacs/current/usr --with-x-toolkit=gtk3
>  --without-xaw3d --with-modules --with-cairo
>  --with-native-compilation=aot --without-pgtk --with-xinput2
>  --with-tree-sitter 'CFLAGS=-isystem
>  /build/emacs/parts/emacs/install/usr/include -isystem
>  /build/emacs/parts/emacs/install/usr/include/x86_64-linux-gnu -isystem
>  /build/emacs/stage/usr/include -O2' 'CPPFLAGS=-isystem
>  /build/emacs/parts/emacs/install/usr/include -isystem
>  /build/emacs/parts/emacs/install/usr/include/x86_64-linux-gnu -isystem
>  /build/emacs/stage/usr/include'
>  'LDFLAGS=-L/build/emacs/parts/emacs/install/lib
>  -L/build/emacs/parts/emacs/install/usr/lib
>  -L/build/emacs/parts/emacs/install/lib/x86_64-linux-gnu
>  -L/build/emacs/parts/emacs/install/usr/lib/x86_64-linux-gnu
>  -L/build/emacs/stage/usr/lib''
>
> From fb3a8b70448a21d359d104071085d0f7d1985531 Mon Sep 17 00:00:00 2001
> From: Alcor <alcor <at> tilde.club>
> Date: Wed, 1 Oct 2025 20:05:53 +0200
> Subject: [PATCH] Improve undo behavior in Rcirc
>
> * lisp/net/rcirc.el (rcirc-update-prompt): Don't track undo info.
> (rcirc-send-input): Clear undo list after message is sent.
> (rcirc-update-undo-list): Add new function (copied from erc.el).
> (rcirc-print): Update (shift) undo list instead of clearing it.
> ---
>  lisp/net/rcirc.el | 41 +++++++++++++++++++++++++++++++++++------
>  1 file changed, 35 insertions(+), 6 deletions(-)
>
> diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
> index a7f1d8b..f6bf4a3 100644
> --- a/lisp/net/rcirc.el
> +++ b/lisp/net/rcirc.el
> @@ -1577,7 +1577,8 @@ If ALL is non-nil, update prompts in all IRC buffers."
>                      (with-rcirc-process-buffer process
>                        (mapcar 'cdr rcirc-buffer-alist))))
>              (rcirc-process-list))
> -    (let ((inhibit-read-only t)
> +    (let ((buffer-undo-list t)
> +          (inhibit-read-only t)
>            (prompt (or rcirc-prompt "")))
>        (mapc (lambda (rep)
>                (setq prompt
> @@ -1729,6 +1730,7 @@ Create the buffer if it doesn't exist."
>                      rcirc-prompt-end-marker (point))))
>          (dolist (line (split-string input "\n"))
>            (rcirc-process-input-line line))
> +        (setq buffer-undo-list nil)
>          ;; add to input-ring
>          (save-excursion
>            (ring-insert rcirc-input-ring input)
> @@ -2014,6 +2016,30 @@ PROCESS is the process object for the current connection."
>                 (> last-activity-line 0))
>        (- rcirc-current-line last-activity-line))))
>  
> +(defun rcirc-update-undo-list (shift)
> +  ;; Translate buffer positions in buffer-undo-list by SHIFT.

Please write this as a proper docstring!

> +  ;; Copied from erc.el
> +  (unless (or (zerop shift) (atom buffer-undo-list))
> +    (let ((list buffer-undo-list) elt)
> +      (while list
> +        (setq elt (car list))
> +        (cond ((integerp elt)           ; POSITION
> +               (cl-incf (car list) shift))

As we would apply the patch on master, you can just use `incf'.

> +              ((or (atom elt)           ; nil, EXTENT
> +                   ;; (eq t (car elt))  ; (t . TIME)
> +                   (markerp (car elt))) ; (MARKER . DISTANCE)
> +               nil)
> +              ((integerp (car elt))     ; (BEGIN . END)
> +               (cl-incf (car elt) shift)
> +               (cl-incf (cdr elt) shift))
> +              ((stringp (car elt))      ; (TEXT . POSITION)
> +               (cl-incf (cdr elt) (* (if (natnump (cdr elt)) 1 -1) shift)))
> +              ((null (car elt))         ; (nil PROPERTY VALUE BEG . END)
> +               (let ((cons (nthcdr 3 elt)))
> +                 (cl-incf (car cons) shift)
> +                 (cl-incf (cdr cons) shift))))
> +        (setq list (cdr list))))))
> +
>  (defvar rcirc-markup-text-functions
>    '(rcirc-markup-attributes
>      rcirc-color-attributes
> @@ -2042,13 +2068,16 @@ connection."
>                             rcirc-ignore-list))
>                 ;; do not ignore if we sent the message
>                 (not (string= sender (rcirc-nick process))))
> -    (let* ((buffer (rcirc-target-buffer process sender response target text))
> +    (let* (preinsert-prompt-end-position
> +           (buffer (rcirc-target-buffer process sender response target text))
>             (time (if-let* ((time (rcirc-get-tag "time")))
>                       (parse-iso8601-time-string time t)
>                     (current-time)))
>             (inhibit-read-only t))
>        (with-current-buffer buffer
> -        (let ((moving (= (point) rcirc-prompt-end-marker))
> +        (setq preinsert-prompt-end-position (marker-position rcirc-prompt-end-marker))
> +        (let ((buffer-undo-list t)
> +              (moving (= (point) rcirc-prompt-end-marker))
>                (old-point (point-marker)))
>  
>            (setq text (decode-coding-string text rcirc-decode-coding-system))
> @@ -2154,9 +2183,9 @@ connection."
>                              0)
>                      (recenter -1)))))))
>  
> -        ;; flush undo (can we do something smarter here?)
> -        (buffer-disable-undo)
> -        (buffer-enable-undo)
> +        ;; shift undo positions
> +        (rcirc-update-undo-list (- rcirc-prompt-end-marker
> +                                   preinsert-prompt-end-position))
>  
>          ;; record mode line activity
>          (when (and activity

I'll have to try it out, but the rest seems fine.  It it also blocked by
your CA process, unless there has been news that I have missed?

Message #14 received at 79551 <at> debbugs.gnu.org (full text, mbox):

From: alcor <at> tilde.club
To: "Philip Kaludercic" <philipk <at> posteo.net>, "Bug reports for GNU Emacs, the
 Swiss army knife of text  editors" <bug-gnu-emacs <at> gnu.org>
Cc: 79551 <at> debbugs.gnu.org
Subject: Re: bug#79551: [PATCH] Improve undo behavior in Rcirc
Date: Mon, 13 Oct 2025 18:02:55 +0000

[Message part 1 (text/plain, inline)]

Am 10. Oktober 2025 um 23:32 schrieb "Philip Kaludercic" <philipk <at> posteo.net>:

> Please write this as a proper docstring!

Done in the revised patch (see attachment).

> As we would apply the patch on master, you can just use `incf'.

Also done in the revised patch.

> I'll have to try it out, but the rest seems fine. It it also blocked by
> your CA process, unless there has been news that I have missed?

The required documents have been sent off-list.

Cheers,
-F.M.

[0001-Improve-undo-behavior-in-Rcirc.patch (text/x-diff, attachment)]

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