vec buffer: send ListDiff::Clear before refilling vec with new values in with_data_arc_port()

src/buffer/vec.rs

@@ -86,6 +86,7 @@ where
     pub fn with_data_arc_port(data: Arc<RwLock<Vec<T>>>, port: InnerViewPort<RwLock<Vec<T>>>) -> Self {
         port.set_view(Some(data.clone()));
 
+        port.notify(&VecDiff::Clear);
         for x in data.read().unwrap().iter().cloned() {
             port.notify(&VecDiff::Push(x));
         }