Add left section to /keys/changes

synapse/handlers/device.py

@@ -326,13 +326,23 @@ class DeviceHandler(BaseHandler):
                         possibly_changed.add(state_key)
                         break
 
+        if possibly_changed:
             users_who_share_room = yield self.store.get_users_who_share_room_with_user(
                 user_id
             )
 
             # Take the intersection of the users whose devices may have changed
             # and those that actually still share a room with the user
-        defer.returnValue(users_who_share_room & possibly_changed)
+            possibly_joined = possibly_changed & users_who_share_room
+            possibly_left = possibly_changed - users_who_share_room
+        else:
+            possibly_joined = []
+            possibly_left = []
+
+        defer.returnValue({
+            "changed": list(possibly_joined),
+            "left": list(possibly_left),
+        })
 
     @defer.inlineCallbacks
     def on_federation_query_user_devices(self, user_id):

synapse/handlers/sync.py

@@ -949,7 +949,7 @@ class SyncHandler(object):
         newly_joined_rooms = []
         room_entries = []
         invited = []
-        for room_id, events in mem_change_events_by_room_id.items():
+        for room_id, events in mem_change_events_by_room_id.iteritems():
             non_joins = [e for e in events if e.membership != Membership.JOIN]
             has_join = len(non_joins) != len(events)
 

synapse/rest/client/v2_alpha/keys.py

@@ -188,13 +188,11 @@ class KeyChangesServlet(RestServlet):
 
         user_id = requester.user.to_string()
 
-        changed = yield self.device_handler.get_user_ids_changed(
+        results = yield self.device_handler.get_user_ids_changed(
             user_id, from_token,
         )
 
-        defer.returnValue((200, {
-            "changed": list(changed),
-        }))
+        defer.returnValue((200, results))
 
 
 class OneTimeKeyServlet(RestServlet):