From e9fd32de791aa95ccfd8adf9959ba789fcefb432 Mon Sep 17 00:00:00 2001
From: Chris Eager <chris@signal.org>
Date: Tue, 26 Jul 2022 12:17:12 -0500
Subject: [PATCH] Only attempt to unsubscribe if the queue name is not null

---
 .../textsecuregcm/storage/MessagesCache.java             | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagesCache.java b/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagesCache.java
index 17938f661..3157e4fb9 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagesCache.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagesCache.java
@@ -36,6 +36,7 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ExecutorService;
 import java.util.stream.Collectors;
+import javax.annotation.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.entities.MessageProtos;
@@ -309,12 +310,12 @@ public class MessagesCache extends RedisClusterPubSubAdapter<String, String> imp
   }
 
   public void removeMessageAvailabilityListener(final MessageAvailabilityListener listener) {
-    final String queueName = queueNamesByMessageListener.remove(listener);
+    @Nullable final String queueName = queueNamesByMessageListener.remove(listener);
 
-    unsubscribeFromKeyspaceNotifications(queueName);
+    if (queueName != null) {
+      unsubscribeFromKeyspaceNotifications(queueName);
 
-    synchronized (messageListenersByQueueName) {
-      if (queueName != null) {
+      synchronized (messageListenersByQueueName) {
         messageListenersByQueueName.remove(queueName);
       }
     }