From 0d2d046709270797f46a65672a5702b194dabef9 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 4 Mar 2019 16:04:04 +0000
Subject: [PATCH] Fix missing null guard

---
 synapse/visibility.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/synapse/visibility.py b/synapse/visibility.py
index 8b9c7180b6..e9dc73c25e 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -237,7 +237,7 @@ def filter_events_for_server(store, server_name, events, redact=True,
     """
 
     def is_sender_erased(event, erased_senders):
-        if erased_senders[event.sender]:
+        if erased_senders and erased_senders[event.sender]:
             logger.info(
                 "Sender of %s has been erased, redacting",
                 event.event_id,