Ensure that the latest wrapper is used when processing detached nodes

src/widget-core/vdom.ts

@@ -1306,18 +1306,19 @@ export function renderer(renderer: () => WNode | VNode): Renderer {
 				let wrappers = current.childrenWrappers || [];
 				let wrapper: DNodeWrapper | undefined;
 				while ((wrapper = wrappers.pop())) {
-					if (wrapper.childrenWrappers) {
-						wrappers.push(...wrapper.childrenWrappers);
-						wrapper.childrenWrappers = undefined;
-					}
 					if (isWNodeWrapper(wrapper)) {
+						wrapper = wrapper.instance ? _instanceToWrapperMap.get(wrapper.instance) || wrapper : wrapper;
 						if (wrapper.instance) {
 							_instanceToWrapperMap.delete(wrapper.instance);
 							const instanceData = widgetInstanceMap.get(wrapper.instance);
 							instanceData && instanceData.onDetach();
 						}
 						wrapper.instance = undefined;
 					}
+					if (wrapper.childrenWrappers) {
+						wrappers.push(...wrapper.childrenWrappers);
+						wrapper.childrenWrappers = undefined;
+					}
 					_wrapperSiblingMap.delete(wrapper);
 					_parentWrapperMap.delete(wrapper);
 					wrapper.domNode = undefined;

tests/widget-core/unit/vdom.ts

@@ -1376,6 +1376,63 @@ jsdomDescribe('vdom', () => {
 			assert.strictEqual((div.childNodes[0]!.childNodes[0] as Text).data, 'Child One');
 		});
 
+		it('should always use the latest wrapper when processing removed nodes', () => {
+			let invalidateFoo: any;
+			let fooRenderCount = 0;
+			class Foo extends WidgetBase {
+				constructor() {
+					super();
+					invalidateFoo = () => {
+						this.invalidate();
+					};
+				}
+				render() {
+					fooRenderCount++;
+					return 'Foo';
+				}
+			}
+
+			let switchFoo: any;
+			class Bar extends WidgetBase {
+				private _showFoo = false;
+				constructor() {
+					super();
+					switchFoo = () => {
+						this._showFoo = !this._showFoo;
+						this.invalidate();
+					};
+				}
+				render() {
+					return v('div', [v('div', [!this._showFoo ? v('div') : w(Foo, {})])]);
+				}
+			}
+
+			let showApp: any;
+			class App extends WidgetBase {
+				private _showApp = true;
+				constructor() {
+					super();
+					showApp = () => {
+						this._showApp = !this._showApp;
+						this.invalidate();
+					};
+				}
+				render() {
+					return this._showApp ? v('div', [w(Bar, {})]) : null;
+				}
+			}
+
+			const div = document.createElement('div');
+			const r = renderer(() => w(App, {}));
+			r.mount({ domNode: div, sync: true });
+			assert.strictEqual(fooRenderCount, 0);
+			switchFoo();
+			assert.strictEqual(fooRenderCount, 1);
+			showApp();
+			invalidateFoo();
+			assert.strictEqual(fooRenderCount, 1);
+		});
+
 		it('should allow a widget returned from render', () => {
 			class Bar extends WidgetBase<any> {
 				render() {