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

[Eli Zaretskii]

> Date: Fri, 12 Aug 2022 17:55:49 +0000 (UTC)
> From: Van Ly <van.ly@sdf.org>
> 
> 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.

Which part of the 2C mode documentation led you to expect to see just
one window after "F2 1"?