Send m-notifyresp-ind (NotifyRespInd) for retrieved MMS on Lollipop API

src/org/thoughtcrime/securesms/mms/IncomingLollipopMmsConnection.java

@@ -26,10 +26,15 @@ import android.support.annotation.Nullable;
 import android.telephony.SmsManager;
 import android.util.Log;
 
+import com.google.android.mms.InvalidHeaderValueException;
+import com.google.android.mms.pdu_alt.NotifyRespInd;
+import com.google.android.mms.pdu_alt.PduComposer;
+import com.google.android.mms.pdu_alt.PduHeaders;
 import com.google.android.mms.pdu_alt.PduParser;
 import com.google.android.mms.pdu_alt.RetrieveConf;
 
 import org.thoughtcrime.securesms.providers.MmsBodyProvider;
+import org.thoughtcrime.securesms.transport.UndeliverableMessageException;
 import org.thoughtcrime.securesms.util.Util;
 
 import java.io.ByteArrayOutputStream;
@@ -89,7 +94,9 @@ public class IncomingLollipopMmsConnection extends LollipopMmsConnection impleme
 
       Log.w(TAG, baos.size() + "-byte response: ");// + Hex.dump(baos.toByteArray()));
 
-      return (RetrieveConf) new PduParser(baos.toByteArray()).parse();
+      RetrieveConf retrieved = (RetrieveConf) new PduParser(baos.toByteArray()).parse();
+      sendRetrievedAcknowledgement(transactionId, retrieved.getMmsVersion(), subscriptionId);
+      return retrieved;
     } catch (IOException | TimeoutException e) {
       Log.w(TAG, e);
       throw new MmsException(e);
@@ -97,4 +104,15 @@ public class IncomingLollipopMmsConnection extends LollipopMmsConnection impleme
       endTransaction();
     }
   }
+
+  private void sendRetrievedAcknowledgement(byte[] transactionId, int mmsVersion, int subscriptionId) {
+    try {
+      NotifyRespInd retrieveResponse = new NotifyRespInd(mmsVersion, transactionId, PduHeaders.STATUS_RETRIEVED);
+      new OutgoingLollipopMmsConnection(getContext()).send(new PduComposer(getContext(), retrieveResponse).make(), subscriptionId);
+    } catch (UndeliverableMessageException e) {
+      Log.w(TAG, e);
+    } catch (InvalidHeaderValueException e) {
+      Log.w(TAG, e);
+    }
+  }
 }