2 files changed, 15 insertions, 10 deletions
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index 4cf4957a42..ba34573d46 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -280,15 +280,11 @@ class FederationClient(FederationBase):
         logger.debug("backfill transaction_data=%r", transaction_data)
 
         if not isinstance(transaction_data, dict):
-            # TODO we probably want an exception type specific to federation
-            # client validation.
-            raise TypeError("Backfill transaction_data is not a dict.")
+            raise InvalidResponseError("Backfill transaction_data is not a dict.")
 
         transaction_data_pdus = transaction_data.get("pdus")
         if not isinstance(transaction_data_pdus, list):
-            # TODO we probably want an exception type specific to federation
-            # client validation.
-            raise TypeError("transaction_data.pdus is not a list.")
+            raise InvalidResponseError("transaction_data.pdus is not a list.")
 
         room_version = await self.store.get_room_version(room_id)
 
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index c05d598b70..bedbd23ded 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -16,6 +16,7 @@
 import logging
 import urllib
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
     Collection,
@@ -42,18 +43,21 @@ from synapse.api.urls import (
 )
 from synapse.events import EventBase, make_event_from_dict
 from synapse.federation.units import Transaction
-from synapse.http.matrixfederationclient import ByteParser
+from synapse.http.matrixfederationclient import ByteParser, LegacyJsonSendParser
 from synapse.http.types import QueryParams
 from synapse.types import JsonDict
 from synapse.util import ExceptionBundle
 
+if TYPE_CHECKING:
+    from synapse.app.homeserver import HomeServer
+
 logger = logging.getLogger(__name__)
 
 
 class TransportLayerClient:
     """Sends federation HTTP requests to other servers"""
 
-    def __init__(self, hs):
+    def __init__(self, hs: "HomeServer"):
         self.server_name = hs.hostname
         self.client = hs.get_federation_http_client()
         self._faster_joins_enabled = hs.config.experimental.faster_joins_enabled
@@ -133,7 +137,7 @@ class TransportLayerClient:
 
     async def backfill(
         self, destination: str, room_id: str, event_tuples: Collection[str], limit: int
-    ) -> Optional[JsonDict]:
+    ) -> Optional[Union[JsonDict, list]]:
         """Requests `limit` previous PDUs in a given context before list of
         PDUs.
 
@@ -388,6 +392,7 @@ class TransportLayerClient:
             # server was just having a momentary blip, the room will be out of
             # sync.
             ignore_backoff=True,
+            parser=LegacyJsonSendParser(),
         )
 
     async def send_leave_v2(
@@ -445,7 +450,11 @@ class TransportLayerClient:
         path = _create_v1_path("/invite/%s/%s", room_id, event_id)
 
         return await self.client.put_json(
-            destination=destination, path=path, data=content, ignore_backoff=True
+            destination=destination,
+            path=path,
+            data=content,
+            ignore_backoff=True,
+            parser=LegacyJsonSendParser(),
         )
 
     async def send_invite_v2(