Re: [PATCH] Fix display-buffer-use-some-window to honor reusable-frames

[Tom Gillespie <tgbugs@gmail.com>]

> Why?  Any reusable frame would have been already honored by
'display-buffer-reuse-window'.

If 'display-buffer-reuse-window' fails to find a valid window then
the next function to run will be 'display-buffer-use-some-window'.

In the current implementation of 'display-buffer-use-some-window'
get-lru-window only searches the existing frame and not-this-window
will be true, therefore whenever there is a single window in the
current frame 'display-buffer-use-some-window' will proceed on to
pick a window in another frame starting with visible then 0 for all-frames
when it calls
(get-largest-window 'visible nil not-this-window) and then
(get-largest-window 0 nil not-this-window)

This is not the behavior that we want because a single window in the
current frame will never be able to reach display-buffer-pop-up-window
since 'display-buffer-use-some-window' will succeed on a random window
in a random frame which will almost certainly not be the least recently used.

> Why would you want to change 'display-buffer-use-some-window'?

I don't, but in your example where we call it in
display-buffer-use-least-recent-window then it would have to be
modified since as is it is impossible to get the behavior we need
due to the calls to get-largest-window.