Fix duplicate message handling

app/src/main/java/org/thoughtcrime/securesms/database/Storage.kt

@@ -351,7 +351,7 @@ class Storage(context: Context, helper: SQLCipherOpenHelper) : Database(context,
         DatabaseFactory.getLokiAPIDatabase(context).removeLastDeletionServerID(group, server)
     }
 
-    override fun isDuplicateMessage(timestamp: Long, sender: String): Boolean {
+    override fun isDuplicateMessage(timestamp: Long): Boolean {
         return getReceivedMessageTimestamps().contains(timestamp)
     }
 

app/src/main/java/org/thoughtcrime/securesms/loki/api/PushNotificationService.kt

@@ -27,19 +27,21 @@ class PushNotificationService : FirebaseMessagingService() {
         val data = base64EncodedData?.let { Base64.decode(it) }
         if (data != null) {
             try {
-                JobQueue.shared.add(MessageReceiveJob(MessageWrapper.unwrap(data).toByteArray(),true))
+                val envelopeAsData = MessageWrapper.unwrap(data).toByteArray()
+                val job = MessageReceiveJob(envelopeAsData,true)
+                JobQueue.shared.add(job)
             } catch (e: Exception) {
                 Log.d("Loki", "Failed to unwrap data for message due to error: $e.")
             }
         } else {
             Log.d("Loki", "Failed to decode data for message.")
             val builder = NotificationCompat.Builder(this, NotificationChannels.OTHER)
-                    .setSmallIcon(network.loki.messenger.R.drawable.ic_notification)
-                    .setColor(this.getResources().getColor(network.loki.messenger.R.color.textsecure_primary))
-                    .setContentTitle("Session")
-                    .setContentText("You've got a new message.")
-                    .setPriority(NotificationCompat.PRIORITY_DEFAULT)
-                    .setAutoCancel(true)
+                .setSmallIcon(network.loki.messenger.R.drawable.ic_notification)
+                .setColor(this.getResources().getColor(network.loki.messenger.R.color.textsecure_primary))
+                .setContentTitle("Session")
+                .setContentText("You've got a new message.")
+                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
+                .setAutoCancel(true)
             with(NotificationManagerCompat.from(this)) {
                 notify(11111, builder.build())
             }

libsession/src/main/java/org/session/libsession/database/StorageProtocol.kt

@@ -92,7 +92,7 @@ interface StorageProtocol {
     fun removeLastDeletionServerId(room: String, server: String)
 
     // Message Handling
-    fun isDuplicateMessage(timestamp: Long, sender: String): Boolean
+    fun isDuplicateMessage(timestamp: Long): Boolean
     fun getReceivedMessageTimestamps(): Set<Long>
     fun addReceivedMessageTimestamp(timestamp: Long)
     fun removeReceivedMessageTimestamps(timestamps: Set<Long>)

libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiver.kt

@@ -38,12 +38,6 @@ object MessageReceiver {
         val isOpenGroupMessage = (openGroupServerID != null)
         // Parse the envelope
         val envelope = SignalServiceProtos.Envelope.parseFrom(data)
-        // If the message failed to process the first time around we retry it later (if the error is retryable). In this case the timestamp
-        // will already be in the database but we don't want to treat the message as a duplicate. The isRetry flag is a simple workaround
-        // for this issue.
-        if (storage.isDuplicateMessage(envelope.timestamp, GroupUtil.doubleEncodeGroupID(envelope.source)) && !isRetry) {
-            throw Error.DuplicateMessage
-        }
         // Decrypt the contents
         val ciphertext = envelope.content ?: throw Error.NoData
         var plaintext: ByteArray? = null
@@ -90,8 +84,6 @@ object MessageReceiver {
                 else -> throw Error.UnknownEnvelopeType
             }
         }
-        // Don't process the envelope any further if the message has been handled already
-        if (storage.isDuplicateMessage(envelope.timestamp, sender!!) && !isRetry) throw Error.DuplicateMessage
         // Don't process the envelope any further if the sender is blocked
         if (isBlocked(sender!!)) throw Error.SenderBlocked
         // Parse the proto
@@ -119,6 +111,19 @@ object MessageReceiver {
         var isValid = message.isValid()
         if (message is VisibleMessage && !isValid && proto.dataMessage.attachmentsCount != 0) { isValid = true }
         if (!isValid) { throw Error.InvalidMessage }
+        // If the message failed to process the first time around we retry it later (if the error is retryable). In this case the timestamp
+        // will already be in the database but we don't want to treat the message as a duplicate. The isRetry flag is a simple workaround
+        // for this issue.
+        if (message is ClosedGroupControlMessage && message.kind is ClosedGroupControlMessage.Kind.New) {
+            // Allow duplicates in this case to avoid the following situation:
+            // • The app performed a background poll or received a push notification
+            // • This method was invoked and the received message timestamps table was updated
+            // • Processing wasn't finished
+            // • The user doesn't see the new closed group
+        } else {
+            if (storage.isDuplicateMessage(envelope.timestamp)) { throw Error.DuplicateMessage }
+            storage.addReceivedMessageTimestamp(envelope.timestamp)
+        }
         // Return
         return Pair(message, proto)
     }