From d7314ec2a46868a04a4fca782ed9be307045b83a Mon Sep 17 00:00:00 2001
From: Cody Henthorne <cody@signal.org>
Date: Sun, 24 Sep 2023 21:20:54 -0400
Subject: [PATCH] Fix NPE in group change message processing.

---
 .../securesms/messages/SignalServiceProtoUtil.kt             | 4 ++++
 .../org/thoughtcrime/securesms/mms/MessageGroupContext.java  | 5 +++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/messages/SignalServiceProtoUtil.kt b/app/src/main/java/org/thoughtcrime/securesms/messages/SignalServiceProtoUtil.kt
index 33e14aee61..c23507156a 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/messages/SignalServiceProtoUtil.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/messages/SignalServiceProtoUtil.kt
@@ -6,6 +6,7 @@ import okio.ByteString
 import org.signal.core.util.orNull
 import org.signal.libsignal.protocol.message.DecryptionErrorMessage
 import org.signal.libsignal.zkgroup.groups.GroupMasterKey
+import org.signal.storageservice.protos.groups.local.DecryptedGroupChange
 import org.thoughtcrime.securesms.attachments.Attachment
 import org.thoughtcrime.securesms.attachments.PointerAttachment
 import org.thoughtcrime.securesms.database.model.StoryType
@@ -32,6 +33,9 @@ import kotlin.time.Duration.Companion.seconds
 
 object SignalServiceProtoUtil {
 
+  @JvmStatic
+  val emptyGroupChange: DecryptedGroupChange by lazy { DecryptedGroupChange() }
+
   /** Contains some user data that affects the conversation  */
   val DataMessage.hasRenderableContent: Boolean
     get() {
diff --git a/app/src/main/java/org/thoughtcrime/securesms/mms/MessageGroupContext.java b/app/src/main/java/org/thoughtcrime/securesms/mms/MessageGroupContext.java
index 67e26346cf..c94ce73ce6 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/mms/MessageGroupContext.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/mms/MessageGroupContext.java
@@ -11,6 +11,7 @@ import org.signal.storageservice.protos.groups.local.DecryptedGroup;
 import org.signal.storageservice.protos.groups.local.DecryptedGroupChange;
 import org.signal.storageservice.protos.groups.local.DecryptedMember;
 import org.thoughtcrime.securesms.database.model.databaseprotos.DecryptedGroupV2Context;
+import org.thoughtcrime.securesms.messages.SignalServiceProtoUtil;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.util.Base64;
@@ -161,12 +162,12 @@ public final class MessageGroupContext {
     }
 
     public @NonNull DecryptedGroupChange getChange() {
-      return decryptedGroupV2Context.change;
+      return decryptedGroupV2Context.change != null ? decryptedGroupV2Context.change : SignalServiceProtoUtil.getEmptyGroupChange();
     }
 
     public @NonNull List<? extends ServiceId> getAllActivePendingAndRemovedMembers() {
       DecryptedGroup        groupState  = decryptedGroupV2Context.groupState;
-      DecryptedGroupChange  groupChange = decryptedGroupV2Context.change;
+      DecryptedGroupChange  groupChange = getChange();
 
       return Stream.of(DecryptedGroupUtil.toAciList(groupState.members),
                        DecryptedGroupUtil.pendingToServiceIdList(groupState.pendingMembers),