bug#58175: 29.0.50; M-x window-swap-states during an active mark leaves behind a region overlay

[martin rudalics]

> In the scenario described in this bug report, point is copied to the
> new window, so the result is as expected.  Deactivating the mark also
> does the expected job.  So it looks like adding
> internal-region-overlay to the persistent window parameters is a good
> solution in this case.  I suggest that you try that, maybe you will
> see some problems that I missed.

With emacs -Q put the following text into *scratch*


(push '(internal-region-overlay . t) window-persistent-parameters)

(defvar foo-conf nil)

(defun foo-save ()
  (interactive)
  (setq foo-conf (current-window-configuration)))

(defun foo-restore ()
  (interactive)
  (set-window-configuration foo-conf))

(split-window)

;; (eval-buffer)


evaluate it and do M-x foo-save followed by C-x o.  Move point and
activate the region.  M-x foo-restore now gets me two overlays, one in
the upper and one in the lower window.

Now try again with 'internal-region-overlay' not made persistent, that
is, the first line commented out.  The same scenario gets me one (albeit
illogical) overlay in the upper window only.

martin