fix test

Author: koenvd

src/dropdown/list/dropdown-list.component.ts

@@ -445,6 +445,10 @@ export class DropdownList implements AbstractDropdownView, AfterViewInit, OnDest
 			console.error(`${this.constructor.name}.propagateSelected expects an Array<ListItem>, got ${JSON.stringify(value)}`);
 		}
 		this.onItemsReady(() => {
+			if (this.getListItems().length === 0) {
+				return;
+			}
+			
 			const selectedNewItems = [];
 			for (let newItem of value) {
 				if (newItem.selected) {