Re: master 297d3d2: * lisp/subr.el (dlet): New macro

["Štěpán Němec" <stepnem@gmail.com>]

> branch: master
> commit 297d3d2e0e17185387c47ad5a0ce4dd448ef7a29
> Author: Stefan Monnier <monnier@iro.umontreal.ca>
> Commit: Stefan Monnier <monnier@iro.umontreal.ca>
>
>     * lisp/subr.el (dlet): New macro
>     
>     * lisp/calendar/calendar.el (calendar-dlet*): Use it.
> ---

[...]

> diff --git a/lisp/subr.el b/lisp/subr.el
> index 13515ca..359f51c 100644
> --- a/lisp/subr.el
> +++ b/lisp/subr.el
> @@ -2972,13 +2987,14 @@ This finishes the change group by reverting all of its changes."
>  	;; the body of `atomic-change-group' all changes can be undone.
>  	(widen)
>  	(let ((old-car (car-safe elt))
> -	      (old-cdr (cdr-safe elt)))
> +	      (old-cdr (cdr-safe elt))
> +	      (start-pul pending-undo-list))
>            (unwind-protect
>                (progn
>                  ;; Temporarily truncate the undo log at ELT.
>                  (when (consp elt)
>                    (setcar elt nil) (setcdr elt nil))
> -                (unless (eq last-command 'undo) (undo-start))
> +                (setq pending-undo-list buffer-undo-list)
>                  ;; Make sure there's no confusion.
>                  (when (and (consp elt) (not (eq elt (last pending-undo-list))))
>                    (error "Undoing to some unrelated state"))
> @@ -2991,7 +3007,13 @@ This finishes the change group by reverting all of its changes."
>              ;; Reset the modified cons cell ELT to its original content.
>              (when (consp elt)
>                (setcar elt old-car)
> -              (setcdr elt old-cdr))))))))
> +              (setcdr elt old-cdr)))
> +          ;; Let's not break a sequence of undos just because we
> +          ;; tried to make a change and then undid it: preserve
> +          ;; the original `pending-undo-list' if it's still valid.
> +          (if (eq (undo--last-change-was-undo-p buffer-undo-list)
> +                  start-pul)
> +              (setq pending-undo-list start-pul)))))))

Was including these bug#39680 (27.0.60; electric-pair-mode broken by
undo)-related changes in this commit intentional?

-- 
Štěpán