Properly shut down protocols handler on useless timeout (#892)

core/src/protocols_handler/node_handler.rs

@@ -289,6 +289,7 @@ where
 
         // Poll the handler at the end so that we see the consequences of the method calls on
         // `self.handler`.
+        loop {
             let poll_result = self.handler.poll()?;
 
             if self.handler.connection_keep_alive() {
@@ -324,7 +325,8 @@ where
                 if self.negotiating_in.is_empty() && self.negotiating_out.is_empty() {
                     match connection_shutdown.poll() {
                         Ok(Async::Ready(_)) | Err(_) => {
-                        return Ok(Async::Ready(NodeHandlerEvent::Shutdown))
+                            self.shutdown();
+                            continue;   // We need to poll the handler again.
                         },
                         Ok(Async::NotReady) => {
                             self.connection_shutdown = Some(connection_shutdown);
@@ -335,6 +337,9 @@ where
                 }
             }
 
+            break;
+        }
+
         Ok(Async::NotReady)
     }
 }