Fix MessageId calculation for deprecated MessageQueue

This was preventing introduction messages from getting ACKed.
The introduction tests were modified to check for this.

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -668,7 +668,9 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				acked.add(m);
 			}
 		}
-		transaction.attach(new MessagesAckedEvent(c, acked));
+		if (acked.size() > 0) {
+			transaction.attach(new MessagesAckedEvent(c, acked));
+		}
 	}
 
 	@Override

briar-core/src/main/java/org/briarproject/briar/client/QueueMessageFactoryImpl.java

@@ -14,6 +14,7 @@ import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
+import static org.briarproject.bramble.util.ByteUtils.INT_64_BYTES;
 import static org.briarproject.briar.api.client.QueueMessage.MAX_QUEUE_MESSAGE_BODY_LENGTH;
 import static org.briarproject.briar.api.client.QueueMessage.QUEUE_MESSAGE_HEADER_LENGTH;
 
@@ -39,11 +40,14 @@ class QueueMessageFactoryImpl implements QueueMessageFactory {
 		ByteUtils.writeUint64(queuePosition, raw, MESSAGE_HEADER_LENGTH);
 		System.arraycopy(body, 0, raw, QUEUE_MESSAGE_HEADER_LENGTH,
 				body.length);
-		byte[] timeBytes = new byte[ByteUtils.INT_64_BYTES];
+		byte[] timeBytes = new byte[INT_64_BYTES];
 		ByteUtils.writeUint64(timestamp, timeBytes, 0);
+		byte[] bodyBytes = new byte[body.length + INT_64_BYTES];
+		System.arraycopy(raw, MESSAGE_HEADER_LENGTH, bodyBytes, 0,
+				body.length + INT_64_BYTES);
 		MessageId id = new MessageId(
 				crypto.hash(MessageId.LABEL, groupId.getBytes(), timeBytes,
-						body));
+						bodyBytes));
 		return new QueueMessage(id, groupId, timestamp, queuePosition, raw);
 	}
 

briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java

@@ -19,6 +19,7 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.sync.Group;
@@ -360,6 +361,14 @@ public class IntroductionIntegrationTest
 		eventWaiter.await(TIMEOUT, 1);
 		assertTrue(listener0.response1Received);
 
+		// sync fake transport properties back to 1, so Message ACK can arrive
+		// and the assertDefaultUiMessages() check at the end will not fail
+		TransportProperties tp = new TransportProperties(
+				Collections.singletonMap("key", "value"));
+		c0.getTransportPropertyManager()
+				.mergeLocalProperties(new TransportId("fake"), tp);
+		sync0To1(1, true);
+
 		// sync second response
 		sync2To0(1, true);
 		eventWaiter.await(TIMEOUT, 1);
@@ -836,14 +845,32 @@ public class IntroductionIntegrationTest
 	}
 
 	private void assertDefaultUiMessages() throws DbException {
-		assertEquals(2, introductionManager0.getIntroductionMessages(
-				contactId1From0).size());
-		assertEquals(2, introductionManager0.getIntroductionMessages(
-				contactId2From0).size());
-		assertEquals(2, introductionManager1.getIntroductionMessages(
-				contactId0From1).size());
-		assertEquals(2, introductionManager2.getIntroductionMessages(
-				contactId0From2).size());
+		Collection<IntroductionMessage> messages =
+				introductionManager0.getIntroductionMessages(contactId1From0);
+		assertEquals(2, messages.size());
+		assertMessagesAreAcked(messages);
+
+		messages = introductionManager0.getIntroductionMessages(
+				contactId2From0);
+		assertEquals(2, messages.size());
+		assertMessagesAreAcked(messages);
+
+		messages = introductionManager1.getIntroductionMessages(
+				contactId0From1);
+		assertEquals(2, messages.size());
+		assertMessagesAreAcked(messages);
+
+		messages = introductionManager2.getIntroductionMessages(
+				contactId0From2);
+		assertEquals(2, messages.size());
+		assertMessagesAreAcked(messages);
+	}
+
+	private void assertMessagesAreAcked(
+			Collection<IntroductionMessage> messages) {
+		for (IntroductionMessage msg : messages) {
+			if (msg.isLocal()) assertTrue(msg.isSeen());
+		}
 	}
 
 	private void addListeners(boolean accept1, boolean accept2) {