Properly preserve an empty dict.

matrix-org · May 12, 2023 · d315438 · d315438
1 parent 5e66a62
commit d315438
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Showing 2 changed files with 23 additions and 6 deletions.
diff --git a/synapse/events/utils.py b/synapse/events/utils.py
@@ -133,13 +133,12 @@ def add_fields(*fields: str) -> None:
         if room_version.msc3821_redaction_rules:
             # Preserve the signed field under third_party_invite.
             third_party_invite = event_dict["content"].get("third_party_invite")
-            if third_party_invite and isinstance(
-                third_party_invite, collections.abc.Mapping
-            ):
+            if isinstance(third_party_invite, collections.abc.Mapping):
+                new_content["third_party_invite"] = {}
                 if "signed" in third_party_invite:
-                    new_content["third_party_invite"] = {
-                        "signed": third_party_invite["signed"]
-                    }
+                    new_content["third_party_invite"]["signed"] = third_party_invite[
+                        "signed"
+                    ]
 
     elif event_type == EventTypes.Create:
         # MSC2176 rules state that create events cannot be redacted.

diff --git a/tests/events/test_utils.py b/tests/events/test_utils.py
@@ -462,6 +462,24 @@ def test_member(self) -> None:
         )
 
         # Ensure this doesn't break if an invalid field is sent.
+        self.run_test(
+            {
+                "type": "m.room.member",
+                "content": {
+                    "membership": "invite",
+                    "third_party_invite": {},
+                    "other_key": "stripped",
+                },
+            },
+            {
+                "type": "m.room.member",
+                "content": {"membership": "invite", "third_party_invite": {}},
+                "signatures": {},
+                "unsigned": {},
+            },
+            room_version=RoomVersions.MSC3821,
+        )
+
         self.run_test(
             {
                 "type": "m.room.member",