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

[martin rudalics]

> Well sure. This was a contrived example specifically constructed to show
> this behavior. The original bug report came from seeing this during
> normal use of gud, so I still think the complaint is valid.

OK.  I believe you.

> I think this is only a question of defaults. Specifically, any time we
> (pop-to-buffer) or (display-buffer) in response to an interactive user
> action, we should default to not covering up the user's buffer. This
> would apply to use cases like gud, diff, cscope and so on. I don't know
> enough about the development of this to know if it makes sense to change
> the defaults only in the interactive case or in general. Do you see
> reasons to keep the default as it is?

The exclusion would be one and one only: namely that the buffer these
functions are supposed to show has appeared in the selected window
before.  In general a user might want to see *Help* or *info* at a
location where she has seen it before and not literally jump through the
available windows of the frame.  Maybe this misfires in the case at hand.

martin