Don't send reply messages for non-method calls in QDBusMessage

QDBusMessage is intended to avoid sending reply messages unless
the message is a method call without the NO_REPLY_EXPECTED flag set.
However, since messages which are not method calls will never have
this flag set, the code will currently cause all non-method call
messages to expect a reply.  This patch changes the code to examine
the message type, and to only check for the flag in cases where the
message is a method call.

Change-Id: Ic5bb00df69d3cfb38f60bf6bfd8463fb28cf2c99
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbusmessage.cpp

@@ -605,6 +605,10 @@ QString QDBusMessage::signature() const
 */
 bool QDBusMessage::isReplyRequired() const
 {
+    // Only method calls can have replies
+    if (d_ptr->type != DBUS_MESSAGE_TYPE_METHOD_CALL)
+        return false;
+
     if (!d_ptr->msg)
         return d_ptr->localMessage; // if it's a local message, reply is required
     return !q_dbus_message_get_no_reply(d_ptr->msg);