> As for the checks for bf_releasebuffer: I still think they are
> necessary. If an object implements bf_releasebuffer, that means that the
> object may change the buffer underneath, unless proper locking and
> unlocking takes place.

I know, but the problem is that by switching some argument definitions
to "s*" and friends we have broken compatibility for the (admittedly
uncommon) use case of giving an array object to those functions. Since
we probably don't want to backout those changes perhaps adding support
for the new buffer API to the array object is the best course of action.