From aaa70e26a2eb37fbdf728393148e003dc9866afd Mon Sep 17 00:00:00 2001
From: Matthew Hodgson <matthew@matrix.org>
Date: Wed, 1 Jun 2016 22:13:47 +0100
Subject: [PATCH] special case m.room.third_party_invite event auth to match
 invites, otherwise they get out of sync and you get
 https://github.com/vector-im/vector-web/issues/1208

---
 synapse/api/auth.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index 2474a1453b..007a0998a7 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -120,6 +120,24 @@ class Auth(object):
                 return allowed
 
             self.check_event_sender_in_room(event, auth_events)
+
+            # Special case to allow m.room.third_party_invite events wherever
+            # a user is allowed to issue invites.  Fixes
+            # https://github.com/vector-im/vector-web/issues/1208 hopefully
+            if event.type == EventTypes.ThirdPartyInvite:
+                user_level = self._get_user_power_level(event.user_id, auth_events)
+                invite_level = self._get_named_level(auth_events, "invite", 0)
+
+                if user_level < invite_level:
+                    raise AuthError(
+                        403, (
+                            "You cannot issue a third party invite for %s." %
+                            (event.content.display_name,)
+                        )
+                    )
+                else:
+                    return True
+
             self._can_send_event(event, auth_events)
 
             if event.type == EventTypes.PowerLevels: