From 4b1a0259fcd6147f48b332a45fb6cc8eb45522ad Mon Sep 17 00:00:00 2001
From: Jon Chambers <jon@signal.org>
Date: Tue, 13 Jan 2026 16:03:11 -0500
Subject: [PATCH] Resolve a warning about potentially-null results from a
 `Flux#toList` call

---
 .../textsecuregcm/controllers/KeysController.java             | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/KeysController.java b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/KeysController.java
index 8359d8341..00ebc32e9 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/KeysController.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/KeysController.java
@@ -38,6 +38,7 @@ import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.time.Clock;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
@@ -384,7 +385,8 @@ public class KeysController {
                 devicePreKeys.ecPreKey().orElse(null),
                 devicePreKeys.kemSignedPreKey())))
         .collectList()
-        .block();
+        .blockOptional()
+        .orElseGet(Collections::emptyList);
 
     final IdentityKey identityKey = target.getIdentityKey(targetIdentifier.identityType());