don't try to modify a non-existant result github/uhoreg/e2e_cross-signing uhoreg/e2e_cross-signing

1 files changed, 2 insertions, 1 deletions

diff --git a/synapse/storage/end_to_end_keys.py b/synapse/storage/end_to_end_keys.py

index edfacf36db..6b732cf670 100644
--- a/synapse/storage/end_to_end_keys.py
+++ b/synapse/storage/end_to_end_keys.py
@@ -153,7 +153,8 @@ class EndToEndKeyStore(SQLBaseStore):
             user_id = attestation["user_id"]
             device_id = attestation["device_id"]
             # FIXME: combine signatures of the same payload?
-            if user_id in result and device_id in result[user_id]:
+            if user_id in result and device_id in result[user_id] \
+               and result[user_id][device_id]:
                 result[user_id][device_id].setdefault("attestations", []) \
                     .append(attestation)