bug#57161: 28.1.91; two column windows merge leaves 2nd column window showing

[Van Ly]

After entering a line of text in two column mode the merge operation 
leaves the second column window showing

 . http://sdf.org/~van.ly/img/emacs-2C-merge--fails.jpg

Unexpected result in the above picture shows second column window.

Steps to reproduce

 . start "emacs -Q"
 . open file "/dev/shm/text.text"
 . enter two column mode by "F2 2"
 . enter a line of text in two column windows
 . merge the two column windows by "F2 1"

Expected result has one window with one line of text in two columns.

--
vl
                                 ALPINE 2.24 GNU Emacs 27.2 NetBSD 9.3

bug-gnu-emacs-28-1-91.text
Description: bug report