[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

bug#33341: 27.0.50; Undo log merging and change groups

From: Michael Heerdegen
Subject: bug#33341: 27.0.50; Undo log merging and change groups
Date: Fri, 27 Nov 2020 02:11:23 +0100
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux)

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Could you check why it breaks in the absence of an undo-boundary?

I have edebugged `org-entry-get'.  Short version: it is as it seems.
Here is the example again:

#+begin_src emacs-lisp
(defun my-test-change-groups ()
  (insert "0\n")
  ;; (undo-boundary)
  (let ((g (prepare-change-group)))
    (activate-change-group g)
    (insert "b\n")
    (insert "c\n")
    (cancel-change-group g)))

Without the boundary, all changes are combined into one (1 . 10) undo
entry.  And then these code lines

#+begin_src emacs-lisp
;; Temporarily truncate the undo log at ELT.
(when (consp elt)
  (setcar elt nil) (setcdr elt nil))

cause that were the undo should happen:

#+begin_src emacs-lisp
;; Undo it all.
  (while (listp pending-undo-list) (undo-more 1)))

nothing is undone.

With the boundary, we have two undo entries, and the truncated log still
contains the entry for the first `insert' call.



reply via email to

[Prev in Thread] Current Thread [Next in Thread]