Subject: Re: bug#7865: Bug in display-buffer-reuse-frames [was Re: bug#7865: 24.0.50; doc of display-buffer-reuse-frames]

From: martin rudalics <[email-masked]>
Date: Mon, 14 Feb 2011 21:04:30 +0100

>> I suppose you mean "if `display-buffer-reuse-frames' is nil and
 >> `pop-up-frames' is t" in the first sentence above.  In that case I'd
 >> agree.
 >
 > I'm confused here.  Which case are we talking about, which behavior is
 > not desired, and which alternative behavior would you(plural) prefer?

When a buffer is already displayed, `display-buffer-reuse-frames' is nil
and `pop-up-frames' is non-nil, `display-buffer' reuses a window.  So if
you set the default of `display-buffer-reuse-frames' to t as someone
proposed, customizing `display-buffer-reuse-frames' will have no effect
when `pop-up-frames' is non-nil.  I don't know whether this is desired
or not and I don't care about the alternatives because `pop-up-frames'
is nil here.

I guess that `display-buffer-reuse-frames' was invented for something
like the following use case:

- The user has `pop-up-frames' nil.

- An application binds `pop-up-frames' to non-nil and pops up a buffer
   in a new frame.

- The user returns to her old frame and eventually does something like
   `pop-to-buffer' on that buffer which should get her to the new frame.

This means that setting `display-buffer-reuse-frames' to t makes sense
iff `pop-up-frames' is nil and the scenario I described above does not
apply, usually.  It's still confusing in my opinion, though.

martin