bug#9532: 24.0.50; `special-display-regexps' is no longer respected

[Chong Yidong]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> M-: (setq special-display-regexps '("foo")) RET
>> M-: (get-buffer-create "foo") RET
>> M-x switch-to-buffer RET foo RET
>>
>> In Emacs 23, this switches to the "foo" buffer in the selected window.
>> With the proposed change, the direct switch-to-buffer call opens it in a
>> special window (just like the switch-to-buffer call in `info').
>
>> So we would be swapping on backward incompatibility for another.
>
> M-x switch-to-buffer should never call display-buffer.
> Only non-interactive calls should do that.

So, you agree to the incompatibility for the non-interactive case?  That
is to say, a non-interactive call to switch-to-buffer (and ONLY a
non-interactive call) will now trigger special display.  Previously, in
Emacs 23, it would use the selected window.

If you agree, I'd implement the behavior by adding a new value for
s-t-b's FORCE-SAME-WINDOW argument, `try', which would be the default
for interactive calls.  That would mean to first try displaying in the
current selected window directly instead of going through p-t-b.

It would be quite unfortunate to have interactive and non-interactive
calls to s-t-b do slightly different things; but maybe it can't be
helped.