GNU bug report logs - #79200
31.0.50; Duplicated elements for '#<marker at' in buffer-undo-list

Previous Next

Full log

Message #146 received at 79200 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Gerd Möllmann <gerd.moellmann <at> gmail.com>
Cc: 79200 <at> debbugs.gnu.org, pipcet <at> protonmail.com, oscarfv <at> telefonica.net,
 monnier <at> iro.umontreal.ca, me <at> pengjiz.com
Subject: Re: bug#79200: 31.0.50;
 Duplicated elements for '#<marker at' in buffer-undo-list
Date: Sat, 09 Aug 2025 16:46:11 +0300

> Cc: 79200 <at> debbugs.gnu.org, oscarfv <at> telefonica.net, monnier <at> iro.umontreal.ca,
>  me <at> pengjiz.com
> From: Gerd Möllmann <gerd.moellmann <at> gmail.com>
> Date: Sat, 09 Aug 2025 15:18:39 +0200
> 
> Another thought: the format_mode_line_unwind is only called from
> display_mode_line (redisplay) and format-mode-line. Why does soemthing
> land in the undo list at all? DOes that make sense at all?

Because it creates a marker:

      ASET (vector, 11, build_marker (current_buffer, PT, PT_BYTE));

And then, when you delete text at point, Emacs adjusts all the
markers, and puts the relevant elements into buffer-undo-list.  So if
you have many markers there, you will have many elements in
buffer-undo-list, one element for each marker.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.