From b62eba770522fde7bf1204eb5771ee24d9a5e7bc Mon Sep 17 00:00:00 2001
From: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
Date: Tue, 17 Aug 2021 12:32:25 +0100
Subject: Always list fallback key types in /sync (#10623)

---
 synapse/rest/client/v2_alpha/sync.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

(limited to 'synapse/rest/client/v2_alpha')

diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py
index e321668698..e18f4d01b3 100644
--- a/synapse/rest/client/v2_alpha/sync.py
+++ b/synapse/rest/client/v2_alpha/sync.py
@@ -259,10 +259,11 @@ class SyncRestServlet(RestServlet):
         # Corresponding synapse issue: https://github.com/matrix-org/synapse/issues/10456
         response["device_one_time_keys_count"] = sync_result.device_one_time_keys_count
 
-        if sync_result.device_unused_fallback_key_types:
-            response[
-                "org.matrix.msc2732.device_unused_fallback_key_types"
-            ] = sync_result.device_unused_fallback_key_types
+        # https://github.com/matrix-org/matrix-doc/blob/54255851f642f84a4f1aaf7bc063eebe3d76752b/proposals/2732-olm-fallback-keys.md
+        # states that this field should always be included, as long as the server supports the feature.
+        response[
+            "org.matrix.msc2732.device_unused_fallback_key_types"
+        ] = sync_result.device_unused_fallback_key_types
 
         if joined:
             response["rooms"][Membership.JOIN] = joined
-- 
cgit 1.4.1