bug#8911: bs-cycle-next deletes window in some cases.

[Stefan Monnier <monnier@iro.umontreal.ca>]

> As I also said earlier, to me (and per the doc string and the
> function's past behavior) `bury-buffer' is not about display.  (That
> is, it is only secondarily about display, and only in the one
> particular case quoted above.)

There are two ways to call bury-buffer, which correspond to two fairly
different behaviors.  One is with a non-nil argument, where it only
touches the order in the buffer-list.  This one is uncontroversial and
doesn't matter much to me.

The other is when the argument is nil, in which case it is
*specifically* meant to make the buffer disappear (additionally to
changing the buffer-list order).  This case is very much about display,
not just secondarily so.

> The reason is primarily the annoyance that iconifying can produce - on
> Windows it is kind of animated, essentially sweeping across the
> display down to the task bar.  With frame deletion it just disappears
> instantly - poof.

Then we could add an option so that bury-buffer uses delete-frame
instead of iconify-frame.  But doing nothing is not an option since the
caller specifically asked to undisplay the buffer.


        Stefan