bug#74361: [PATCH] New option xref-navigation-display-window-action

[Juri Linkov <juri@linkov.net>]

>> I tried your patch, and it works even with 'mru':
>> (setq display-buffer-alist '(((category . xref)
>>                                (display-buffer-reuse-window
>>                                 display-buffer-use-some-window)
>>                                (some-window . mru))))
>
> Yep, even the 'mru' strategy doesn't choose the currently selected window,
> so this should also work well, selecting "some window" in a stable fashion
> (whereas 'lru' - the default - uses a different window each time).

Unless the user customizes it to call with NOT-SELECTED=nil explicitly:

  (setq display-buffer-alist
        '(((category . xref)
           (display-buffer-use-some-window)
           (some-window . (lambda (_buffer alist)
                            (get-mru-window nil nil nil))))))

PS: after testing I noticed that in your patch
nil needs to be added as a placeholder for empty action:

                  `((xref--display-buffer-in-window)
                    (category . xref)
                    (window . ,xref--original-window)))
                 (t
-                 '((category . xref))))))
+                 '(nil (category . xref))))))