Do not raise protocol error

If an unexpected stream id is received there is no need to punish the user by raising a protocol error. Instead we prefer to add a warning message and close that particular stream by sending a reset frame.

Author: jdecuyper

hyper/http20/connection.py

@@ -593,9 +593,8 @@ def _consume_frame_payload(self, frame, data):
                 f = RstStreamFrame(frame.stream_id)
                 f.error_code = 1 # PROTOCOL_ERROR
                 self._send_cb(f)
-                error_string = ("Unexpected stream identifier %d" %
-                                  (frame.stream_id))
-                raise ProtocolError(error_string)
+                log.warning("Unexpected stream identifier %d" %
+                               (frame.stream_id))
         else:
             self.receive_frame(frame)
 

hyper/http20/errors.py

@@ -8,7 +8,7 @@
 the array.
 
 The current registry is available at:
-https://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-11.4
+https://tools.ietf.org/html/rfc7540#section-11.4
 """
 
 NO_ERROR =            {'Name': 'NO_ERROR',

test/test_hyper.py

@@ -1272,9 +1272,16 @@ def data_callback(frame):
 
         f = DataFrame(-1)
         data = memoryview(b"hi there sir")
+        c._consume_frame_payload(f, data)
+
+        # If we receive an unexpected stream id then we cancel the stream
+        # by sending a reset stream that contains the protocol error code (1)
+        f = frames[0]
+        assert len(frames) == 1
+        assert f.stream_id == -1
+        assert isinstance(f, RstStreamFrame)
+        assert f.error_code == 1 # PROTOCOL_ERROR
 
-        with pytest.raises(ProtocolError):
-            c._consume_frame_payload(f, data)
 
 # Some utility classes for the tests.
 class NullEncoder(object):