Assert that we have a local update

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxPropertyManager.java

@@ -57,7 +57,6 @@ public interface MailboxPropertyManager {
 	 */
 	String MSG_KEY_LOCAL = "local";
 
-	@Nullable
 	MailboxPropertiesUpdate getLocalProperties(Transaction txn, ContactId c)
 			throws DbException;
 

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxPropertyManagerImpl.java

@@ -180,10 +180,15 @@ class MailboxPropertyManagerImpl implements MailboxPropertyManager,
 	}
 
 	@Override
-	@Nullable
 	public MailboxPropertiesUpdate getLocalProperties(Transaction txn,
 			ContactId c) throws DbException {
-		return getProperties(txn, db.getContact(txn, c), true);
+		MailboxPropertiesUpdate local =
+				getProperties(txn, db.getContact(txn, c), true);
+		// An update (with or without mailbox) is created when contact is added
+		if (local == null) {
+			throw new DbException();
+		}
+		return local;
 	}
 
 	@Override

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxPropertyManagerImplTest.java

@@ -673,30 +673,6 @@ public class MailboxPropertyManagerImplTest extends BrambleMockTestCase {
 		assertTrue(mailboxPropertiesUpdateEqual(local, updateMailbox));
 	}
 
-	@Test
-	public void testGetLocalPropertiesReturnsNullBecauseNoUpdate()
-			throws Exception {
-		Transaction txn = new Transaction(null, false);
-		Contact contact = getContact();
-		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
-		Map<MessageId, BdfDictionary> emptyMessageMetadata =
-				new LinkedHashMap<>();
-
-		context.checking(new Expectations() {{
-			oneOf(db).getContact(txn, contact.getId());
-			will(returnValue(contact));
-			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
-			will(returnValue(contactGroup));
-			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
-					contactGroup.getId());
-			will(returnValue(emptyMessageMetadata));
-		}});
-
-		MailboxPropertyManagerImpl t = createInstance();
-		assertNull(t.getLocalProperties(txn, contact.getId()));
-	}
-
 	@Test
 	public void testGetLocalPropertiesNoMailbox()
 			throws Exception {