bug#45688: 28.0.50; New action for display-buffer?

[martin rudalics]

> I didn't know this trick.  But it works only for 'C-x 4 f',
> not for 'C-x 4 1':
>
> with enabled temp-buffer-resize-mode
> 1. C-h f push RET
> 2. C-x o TAB
> 3. C-x 4 1 RET
>
> doesn't re-enlarge the window to its prior size.

Only 'display-buffer-use-some-window' currently does.  What does C-x 4 1
call?

martin