fix(runtime-core): stricter compat root mount check

Author: yyx990803

packages/runtime-core/__tests__/rendererComponent.spec.ts

@@ -298,12 +298,10 @@ describe('renderer: component', () => {
  })
 
  test('the component VNode should be cloned when reusing it', () => {
- const Child = {
- setup(props: any, { slots }: SetupContext) {
- return () => {
- const c = slots.default!()
- return [c, c, c]
- }
+ const App = {
+ render() {
+ const c = [h(Comp)]
+ return [c, c, c]
  }
  }
 
@@ -315,14 +313,6 @@ describe('renderer: component', () => {
  }
  }
 
- const App = {
- setup() {
- return () => {
- return h(Child, () => [h(Comp)])
- }
- }
- }
-
  const root = nodeOps.createElement('div')
  render(h(App), root)
  expect(serializeInner(root)).toBe(`<h1></h1><h1></h1><h1></h1>`)

packages/runtime-core/src/compat/global.ts

@@ -472,6 +472,7 @@ function installCompatMount(
  }
  setupComponent(instance)
  vnode.component = instance
+ vnode.isCompatRoot = true
 
  // $mount & $destroy
  // these are defined on ctx and picked up by the $mount/$destroy

packages/runtime-core/src/renderer.ts

@@ -1301,7 +1301,8 @@ function baseCreateRenderer(
  ) => {
  // 2.x compat may pre-creaate the component instance before actually
  // mounting
- const compatMountInstance = __COMPAT__ && initialVNode.component
+ const compatMountInstance =
+ __COMPAT__ && initialVNode.isCompatRoot && initialVNode.component
  const instance: ComponentInternalInstance =
  compatMountInstance ||
  (initialVNode.component = createComponentInstance(

packages/runtime-core/src/vnode.ts

@@ -136,6 +136,11 @@ export interface VNode<
  */
  [ReactiveFlags.SKIP]: true
 
+ /**
+ * @internal __COMPAT__ only
+ */
+ isCompatRoot?: true
+
  type: VNodeTypes
  props: (VNodeProps & ExtraProps) | null
  key: string | number | null