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

[Juri Linkov]

> then the XEmacs `display-buffer' does the right thing for that.

XEmacs does absolutely the wrong thing.  When I have a window
with a source buffer, then run grep in another window, then
want to visit grep hits in the third window, visiting
the next file from the grep window obscures the window
with the source buffer, it doesn't use the same window
where I'm visiting grep hits.

I tried to replace get-lru-window with get-mru-window
but it selects the current window which is mru indeed,
but makes no sense - what is needed is mru-1, then
I tried to set the arg NOT-SELECTED of get-mru-window to t
in display-buffer-use-some-window, then it works sensibly.