bug#20206: 25.0.50; [PATCH] keep diff-mode's window visible when we visit sources from diff-mode

[Dima Kogan]

martin rudalics <rudalics@gmx.at> writes:

>  > 2. The display-buffer-pop-up-window action is there to handle bug 19901.
>  > There the user already has two windows, and by default a third is
>  > created. It's less obvious to me which is the "right" behavior here, but
>  > the earlier behavior of reusing the window seems reasonable.
>
> Agreed.  But if you have a two windows frame and your settings for
> popping up a third window would normally allow that, your solution would
> nevertheless try to use another window in that case.  Wouldn't it be
> sufficient to just use '((inhibit-same-window . t))?

I'm not sure what you mean: '((inhibit-same-window . t)) is not a valid
as an action argument to display-buffer, and emacs barfs if I try to use
it as such. I'm not at all married to using display-buffer-pop-up-window
here. If you have a better idea for solving 19901 (or if you think
there's nothing to fix), then I'm fine with it.

Another wrinkle is that the behavior reported in 19901 as a bug is only
observable with particular geometries of the emacs X11 window. On my
machine, 19901 is reproducible if emacs takes up my whole screen
(1440x1050), but not if it takes only half (720x1050). Presumably emacs
thinks that splitting into a 3rd window will create new windows that are
too narrow. That is all to say that maybe 19901 is not a bug.