GNU bug report logs - #60143
29.0.60; command `undo-redo` don't restore cursor position

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Message #14 received at 60143 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Stefan Monnier <monnier <at> iro.umontreal.ca>
Cc: liuyinz95 <at> gmail.com, 60143 <at> debbugs.gnu.org
Subject: Re: bug#60143: 29.0.60; command `undo-redo` don't restore cursor
 position
Date: Mon, 19 Dec 2022 05:35:49 +0200

> From: Stefan Monnier <monnier <at> iro.umontreal.ca>
> Cc: yinz Liu <liuyinz95 <at> gmail.com>,  60143 <at> debbugs.gnu.org
> Date: Sun, 18 Dec 2022 20:42:31 -0500
> 
> > So I very much hesitate to change this.  Stefan, any comments?
> 
> Changing that code is likely wrong, indeed.  If the undo doesn't get
> you where you expected, it should usually be changed by adding an
> additional record to the undo log.
> 
> That "record" is a simple integer indicating the position of point at
> that moment (citing `C-h o buffer-undo-list`):
> 
>     An entry of the form POSITION indicates that point was at the buffer
>     location given by the integer.  Undoing an entry of this form places
>     point at POSITION.
> 
> As for whether we should add such a record in the OP's scenario, and how
> to do that, I haven't looked at his scenario in enough detail to have
> much to say about it.

I don't think we record position of point before deletion.  Which is
why 'undo' in that scenario also ends up with point before the
recovered deletion.

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