bug#63967: 28.2; switch-to-buffer in normal window fails if minibuffer window is active

[martin rudalics]

>> If w->prev_buffers gets us the right minibuffer to display here (any
>> former dw->prev_buffers = sw->prev_buffers should guarantee that), then
>> for that buffer we have to establish the corresponding start and point
>> positions.  This makes sense regardless of whether the minibuffer window
>> will be selected or not.
>
> But read_minibuf_unwind already does all that when it restores the
> window configuration, doesn't it?  Or is there something about the
> mini-window that restoring window configuration doesn't handle
> correctly?

I can imagine the following scenario: read_minibuf saves and restores up
to two window configurations - the one of the frame from where it was
invoked and the one of the frame that owned the corresponding minibuffer
window at that time.  Now with 'minibuffer-follows-selected-frame'
non-nil there might be another frame the user may want to continue the
interaction with and the configuration of that frame will not be
automatically restored upon exiting read_minibuf.  Yet, the minibuffer
window on that frame should be restored properly to show its previous
buffer, point etc.

martin