don't return async::notready for messages without scheduling wakeup

substrate/polkadot/consensus/src/service.rs

@@ -108,22 +108,22 @@ impl Stream for Messages {
 		}
 
 		// check the network
+		loop {
 			match self.network_stream.poll() {
-			Err(_) => Err(bft::InputStreamConcluded.into()),
+				Err(_) => return Err(bft::InputStreamConcluded.into()),
-			Ok(Async::NotReady) => Ok(Async::NotReady),
+				Ok(Async::NotReady) => return Ok(Async::NotReady),
-			Ok(Async::Ready(None)) => Ok(Async::NotReady), // the input stream for agreements is never meant to logically end.
+				Ok(Async::Ready(None)) => return Ok(Async::NotReady), // the input stream for agreements is never meant to logically end.
 				Ok(Async::Ready(Some(message))) => {
 					if message.parent_hash == self.parent_hash {
 						match process_message(message, &self.authorities) {
-						Ok(message) => Ok(Async::Ready(Some(message))),
+							Ok(message) => return Ok(Async::Ready(Some(message))),
 							Err(e) => {
 								debug!("Message validation failed: {:?}", e);
-							Ok(Async::NotReady)
 							}
 						}
 					} else {
 						self.collection.push(message);
-					Ok(Async::NotReady)
+					}
 				}
 			}
 		}