Handle absent change during invite.

app/src/main/java/org/thoughtcrime/securesms/groups/v2/processing/GroupsV2StateProcessor.java

@@ -9,9 +9,11 @@ import androidx.annotation.WorkerThread;
 
 import org.signal.storageservice.protos.groups.local.DecryptedGroup;
 import org.signal.storageservice.protos.groups.local.DecryptedGroupChange;
+import org.signal.storageservice.protos.groups.local.DecryptedPendingMember;
 import org.signal.zkgroup.VerificationFailedException;
 import org.signal.zkgroup.groups.GroupMasterKey;
 import org.signal.zkgroup.groups.GroupSecretParams;
+import org.signal.zkgroup.util.UUIDUtil;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.GroupDatabase;
 import org.thoughtcrime.securesms.database.MmsDatabase;
@@ -279,7 +281,10 @@ public final class GroupsV2StateProcessor {
       final ProfileKeySet profileKeys = new ProfileKeySet();
 
       for (GroupLogEntry entry : globalGroupState.getHistory()) {
-        profileKeys.addKeysFromGroupState(entry.getGroup(), DecryptedGroupUtil.editorUuid(entry.getChange()));
+        Optional<UUID> editor = DecryptedGroupUtil.editorUuid(entry.getChange());
+        if (editor.isPresent()) {
+          profileKeys.addKeysFromGroupState(entry.getGroup(), editor.get());
+        }
       }
 
       Collection<RecipientId> updated = recipientDatabase.persistProfileKeySet(profileKeys);
@@ -335,8 +340,14 @@ public final class GroupsV2StateProcessor {
     }
 
     private void storeMessage(@NonNull DecryptedGroupV2Context decryptedGroupV2Context, long timestamp) {
-      UUID editor = DecryptedGroupUtil.editorUuid(decryptedGroupV2Context.getChange());
+      Optional<UUID> editor = getEditor(decryptedGroupV2Context);
-      boolean outgoing = Recipient.self().getUuid().get().equals(editor);
+
+      if (!editor.isPresent() || UuidUtil.UNKNOWN_UUID.equals(editor.get())) {
+        Log.w(TAG, "Cannot determine editor of change, can't insert message");
+        return;
+      }
+
+      boolean outgoing = Recipient.self().requireUuid().equals(editor.get());
 
       if (outgoing) {
         try {
@@ -353,12 +364,26 @@ public final class GroupsV2StateProcessor {
         }
       } else {
         SmsDatabase                smsDatabase  = DatabaseFactory.getSmsDatabase(context);
-        RecipientId                sender       = Recipient.externalPush(context, editor, null).getId();
+        RecipientId                sender       = RecipientId.from(editor.get(), null);
         IncomingTextMessage        incoming     = new IncomingTextMessage(sender, -1, timestamp, timestamp, "", Optional.of(groupId), 0, false);
         IncomingGroupUpdateMessage groupMessage = new IncomingGroupUpdateMessage(incoming, decryptedGroupV2Context);
 
         smsDatabase.insertMessageInbox(groupMessage);
       }
     }
+
+    private Optional<UUID> getEditor(@NonNull DecryptedGroupV2Context decryptedGroupV2Context) {
+      DecryptedGroupChange change       = decryptedGroupV2Context.getChange();
+      Optional<UUID>       changeEditor = DecryptedGroupUtil.editorUuid(change);
+      if (changeEditor.isPresent()) {
+        return changeEditor;
+      } else {
+        Optional<DecryptedPendingMember> pendingByUuid = DecryptedGroupUtil.findPendingByUuid(decryptedGroupV2Context.getGroupState().getPendingMembersList(), Recipient.self().requireUuid());
+        if (pendingByUuid.isPresent()) {
+          return Optional.fromNullable(UuidUtil.fromByteStringOrNull(pendingByUuid.get().getAddedByUuid()));
+        }
+      }
+      return Optional.absent();
+    }
   }
 }

libsignal/service/src/main/java/org/whispersystems/signalservice/api/groupsv2/DecryptedGroupUtil.java

@@ -88,8 +88,8 @@ public final class DecryptedGroupUtil {
   /**
    * The UUID of the member that made the change.
    */
-  public static UUID editorUuid(DecryptedGroupChange change) {
+  public static Optional<UUID> editorUuid(DecryptedGroupChange change) {
-    return change != null ? UuidUtil.fromByteStringOrUnknown(change.getEditor()) : UuidUtil.UNKNOWN_UUID;
+    return Optional.fromNullable(change != null ? UuidUtil.fromByteStringOrNull(change.getEditor()) : null);
   }
 
   public static Optional<DecryptedMember> findMemberByUuid(Collection<DecryptedMember> members, UUID uuid) {

libsignal/service/src/main/java/org/whispersystems/signalservice/api/util/UuidUtil.java

@@ -63,11 +63,6 @@ public final class UuidUtil {
     return parseOrNull(bytes.toByteArray());
   }
 
-  public static UUID fromByteStringOrUnknown(ByteString bytes) {
-    UUID uuid = parseOrNull(bytes.toByteArray());
-    return uuid != null ? uuid : UNKNOWN_UUID;
-  }
-
   private static UUID parseOrNull(byte[] byteArray) {
     return byteArray != null && byteArray.length == 16 ? parseOrThrow(byteArray) : null;
   }

libsignal/service/src/test/java/org/whispersystems/signalservice/api/groupsv2/DecryptedGroupUtilTest.java

@@ -34,7 +34,7 @@ public final class DecryptedGroupUtilTest {
                                                            .setEditor(editor)
                                                            .build();
 
-    UUID parsed = DecryptedGroupUtil.editorUuid(groupChange);
+    UUID parsed = DecryptedGroupUtil.editorUuid(groupChange).get();
 
     assertEquals(uuid, parsed);
   }