From f14bce9849a470e8a06d07ece6023dc79ac70bea Mon Sep 17 00:00:00 2001
From: Cody Henthorne <cody@signal.org>
Date: Fri, 21 Apr 2023 12:36:52 -0400
Subject: [PATCH] Fix unable to verify signed group change warning.

---
 .../org/thoughtcrime/securesms/groups/GroupManagerV2.java    | 2 +-
 .../securesms/messages/MessageContentProcessorV2.kt          | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/groups/GroupManagerV2.java b/app/src/main/java/org/thoughtcrime/securesms/groups/GroupManagerV2.java
index e81014d011..cd2470cf3c 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/groups/GroupManagerV2.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/groups/GroupManagerV2.java
@@ -808,7 +808,7 @@ final class GroupManagerV2 {
     }
 
     private DecryptedGroupChange getDecryptedGroupChange(@Nullable byte[] signedGroupChange) {
-      if (signedGroupChange != null) {
+      if (signedGroupChange != null && signedGroupChange.length > 0) {
         GroupsV2Operations.GroupOperations groupOperations = groupsV2Operations.forGroup(GroupSecretParams.deriveFromMasterKey(groupMasterKey));
 
         try {
diff --git a/app/src/main/java/org/thoughtcrime/securesms/messages/MessageContentProcessorV2.kt b/app/src/main/java/org/thoughtcrime/securesms/messages/MessageContentProcessorV2.kt
index b17d4ab7d1..2d30e9c859 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/messages/MessageContentProcessorV2.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/messages/MessageContentProcessorV2.kt
@@ -253,8 +253,9 @@ open class MessageContentProcessorV2(private val context: Context) {
       groupV2: SignalServiceProtos.GroupContextV2
     ): Boolean {
       return try {
-        val updatedTimestamp = if (groupV2.hasSignedGroupChange) timestamp else timestamp - 1
-        GroupManager.updateGroupFromServer(context, groupV2.groupMasterKey, groupV2.revision, updatedTimestamp, groupV2.signedGroupChange)
+        val signedGroupChange: ByteArray? = if (groupV2.hasSignedGroupChange) groupV2.signedGroupChange else null
+        val updatedTimestamp = if (signedGroupChange != null) timestamp else timestamp - 1
+        GroupManager.updateGroupFromServer(context, groupV2.groupMasterKey, groupV2.revision, updatedTimestamp, signedGroupChange)
         true
       } catch (e: GroupNotAMemberException) {
         warn(timestamp, "Ignoring message for a group we're not in")