bug#36680: 27.0.50; undo-tree visualizer flickering with display-buffer-reuse-frames -> t

[Michael Heerdegen <michael_heerdegen@web.de>]

Hi,

recipe from emacs -Q, after getting a source of undo-tree:

Copy to scratch and evaluate

(setq display-buffer-reuse-frames t)
(require 'undo-tree)
(undo-tree-mode)

Make some further edits to scratch for testing.  Then

C-x 5 2
C-x u
[up]...

Any time you switch the current node in the visualizer, the first frame
is raised for a very short time, then lowered again.  This is quite
annoying, it makes C-x u quite useless when you have a window in another
frame displaying the current buffer because it distracts me from seeing
what changes in the buffer, I'm unable to see it.  Setting
display-buffer-reuse-frames -> nil fixes this.

The visualizer calls

  (switch-to-buffer-other-window undo-tree-visualizer-buffer-name)

which doesn't seem to behave well in this situation.

TIA,

Michael.


In GNU Emacs 27.0.50 (build 9, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2019-07-15 built on drachen
Repository revision: fb725fc0fa320e94daf8e4aa1a3320ba60142449
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description: Debian GNU/Linux bullseye/sid