bug#33870: 27.0.50; xref-goto-xref not configurable

[Juri Linkov]

>> Maybe some more suitable name for actions to add between
>> display-buffer-overriding-action and user-action?
>
> Nothing should ever come between 'display-buffer-overriding-action'
> and 'user-action'.

Sorry, rather I wanted to mention 'special-action' because it precedes 'action'
that comes from the display-buffer call (that then could specify just
display-buffer-at-bottom instead of display-buffer--maybe-at-bottom).

>>>> This makes sense.  Even more, maybe it would be possible to use only
>>>> an alist '(side . bottom)' instead of specyfying the action
>>>> 'display-buffer--maybe-at-bottom'?
>>
>> Or '(direction . bottom) or shorter '(dir . bottom)
>> compatible with terminology of window-in-direction
>> because the word "side" is associated with side windows.
>
> Fine with me.
>
>> Maybe better 'frame' instead of 'main'?
>
> No.  'frame' includes side windows (the ones you cite above) and the
> minibuffer window.  'main' (from 'window-main-window') or 'root' are
> better (but still not perfect).

Yes, still not perfect.  Maybe then use just one alist entry with more
possible values whose names clearly indicate where they are applied like

below - bottom
above - top
left - leftmost
right - rightmost

The first column is relative to the selected window,
the second column is relative to the main window.