danabr/node-tftp — pull request #4 by igor-shevchenko (2013-09-12 04:10:11+00:00)
Title: Send ack if stream handled data immediately

`drain` event is emitted only in the case when `stream.write(data)` returns `false` ([docs](http://nodejs.org/api/stream.html#stream_event_drain)). So, if `stream.write(data)` returns `true` (i.e. data's flushed immediately), we also need to send ack and increment block number.