Prevent double-closure.

Author: Lukasa

hyper/http20/connection.py

@@ -343,11 +343,7 @@ def _close_stream(self, stream_id):
         """
         Called by a stream when it would like to be 'closed'.
         """
-        try:
-            del self.streams[stream_id]
-        except KeyError:
-            # If the stream is already missing from the dict, no-one cares.
-            pass
+        del self.streams[stream_id]
 
     def _send_cb(self, frame):
         """

hyper/http20/response.py

@@ -127,6 +127,7 @@ def read(self, amt=None, decode_content=True):
             if decode_content and self._decompressobj:
                 data += self._decompressobj.flush()
 
+        if not data:
             self.close()
 
         return data