Fixed #169: Don't try to send messages to a closed client

daphne/http_protocol.py

@@ -189,8 +189,13 @@ class WebRequest(http.Request):
         """
         Handles a reply from the client
         """
+        # Handle connections that are already closed
+        if self.channel is None:
+            return
+        # Check message validity
         if "type" not in message:
             raise ValueError("Message has no type defined")
+        # Handle message
         if message["type"] == "http.response.start":
             if self._response_started:
                 raise ValueError("HTTP response has already been started")