fix(h2_connection_reset): add stream reset when client cancel the request

Author: MarkLux

httpcore/_async/http2.py

@@ -404,6 +404,12 @@ async def _receive_remote_settings_change(self, event: h2.events.Event) -> None:
     async def _response_closed(self, stream_id: int) -> None:
         await self._max_streams_semaphore.release()
         del self._events[stream_id]
+
+        stream = self._h2_state._get_stream_by_id(stream_id=stream_id)
+        if stream and not stream.closed:
+            # stream closed by client cancel, send a RstStream frame with CancelCode to server
+            self._h2_state.reset_stream(stream_id=stream_id, error_code=h2.settings.ErrorCodes.CANCEL)
+
         async with self._state_lock:
             if self._connection_terminated and not self._events:
                 await self.aclose()