Fix bug in replication where response is cached (#15024)

erikjohnston · web-flow · commit c78c67c5a909 · 2023-02-08T16:41:55.000Z
diff --git a/changelog.d/15024.bugfix b/changelog.d/15024.bugfix
@@ -0,0 +1 @@
+Fix bug where retried replication requests would return a failure. Introduced in v1.76.0.
diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py
@@ -426,6 +426,8 @@ async def _check_auth_and_handle(
             code, response = await self.response_cache.wrap(
                 txn_id, self._handle_request, request, content, **kwargs
             )
+            # Take a copy so we don't mutate things in the cache.
+            response = dict(response)
         else:
             # The `@cancellable` decorator may be applied to `_handle_request`. But we
             # told `HttpServer.register_paths` that our handler is `_check_auth_and_handle`,

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+Fix bug where retried replication requests would return a failure. Introduced in v1.76.0.`
Original file line number	Diff line number	Diff line change
`@@ -426,6 +426,8 @@ async def _check_auth_and_handle(`
`426`	`426`	`code, response = await self.response_cache.wrap(`
`427`	`427`	`txn_id, self._handle_request, request, content, **kwargs`
`428`	`428`	`)`
	`429`	`+ # Take a copy so we don't mutate things in the cache.`
	`430`	`+ response = dict(response)`
`429`	`431`	`else:`
`430`	`432`	# The `@cancellable` decorator may be applied to `_handle_request`. But we
`431`	`433`	# told `HttpServer.register_paths` that our handler is `_check_auth_and_handle`,