hang when trying to drain empty stream

[gregory.petrosyan@xxxxxxxxx (Gregory Petrosyan)]

Hi!

I believe there is a bug in PA: when trying to drain empty stream
(newly created, or just after pa_stream_flush()) returned pa_operation
never completes. Because it's not possible to know in advance if
a stream is empty, IMO pa_stream_drain should succeed ASAP
when called on empty stream, and not hang.

                Gregory