1 files changed, 32 insertions, 3 deletions
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 655c78e150..51b9772329 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -106,6 +106,13 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         self.event_auth_handler = hs.get_event_auth_handler()
         self._worker_lock_handler = hs.get_worker_locks_handler()
 
+        self._membership_types_to_include_profile_data_in = {
+            Membership.JOIN,
+            Membership.KNOCK,
+        }
+        if self.hs.config.server.include_profile_data_on_invite:
+            self._membership_types_to_include_profile_data_in.add(Membership.INVITE)
+
         self.member_linearizer: Linearizer = Linearizer(name="member")
         self.member_as_limiter = Linearizer(max_count=10, name="member_as_limiter")
 
@@ -785,9 +792,8 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         if (
             not self.allow_per_room_profiles and not is_requester_server_notices_user
         ) or requester.shadow_banned:
-            # Strip profile data, knowing that new profile data will be added to the
-            # event's content in event_creation_handler.create_event() using the target's
-            # global profile.
+            # Strip profile data, knowing that new profile data will be added to
+            # the event's content below using the target's global profile.
             content.pop("displayname", None)
             content.pop("avatar_url", None)
 
@@ -823,6 +829,29 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         if action in ["kick", "unban"]:
             effective_membership_state = "leave"
 
+        if effective_membership_state not in Membership.LIST:
+            raise SynapseError(400, "Invalid membership key")
+
+        # Add profile data for joins etc, if no per-room profile.
+        if (
+            effective_membership_state
+            in self._membership_types_to_include_profile_data_in
+        ):
+            # If event doesn't include a display name, add one.
+            profile = self.profile_handler
+
+            try:
+                if "displayname" not in content:
+                    displayname = await profile.get_displayname(target)
+                    if displayname is not None:
+                        content["displayname"] = displayname
+                if "avatar_url" not in content:
+                    avatar_url = await profile.get_avatar_url(target)
+                    if avatar_url is not None:
+                        content["avatar_url"] = avatar_url
+            except Exception as e:
+                logger.info("Failed to get profile information for %r: %s", target, e)
+
         # if this is a join with a 3pid signature, we may need to turn a 3pid
         # invite into a normal invite before we can handle the join.
         if third_party_signed is not None: