Merge branch 'subscribe_many_with_options_one' of github.com:qm3ster/…

…paho.mqtt.rust into subscribe_many_with_options_one

src/async_client.rs

@@ -811,11 +811,17 @@ impl AsyncClient {
         let n = topics.len();
         // TOOD: Make sure topics & qos are same length (or use min)
         let tok = Token::from_request(ServerRequest::SubscribeMany(n));
-        let mut rsp_opts = ResponseOptionsBuilder::new()
-            .token(tok.clone())
+        let mut rsp_opts = ResponseOptionsBuilder::new();
+        rsp_opts.token(tok.clone())
             .subscribe_many_options(opts)
-            .properties(props.into().unwrap_or_default())
-            .finalize();
+            .properties(props.into().unwrap_or_default());
+
+        // This is necessary, as the `MQTTAsync_subscribeMany` paho.mqtt.c function uses `opts` over `optlist` when `count <= 1`
+        if let [opts] = opts {
+            rsp_opts.subscribe_options(*opts);
+        }
+
+        let mut rsp_opts = rsp_opts.finalize();
 
         let topics = StringCollection::new(topics);