fix(compat): include legacy scoped slots

close vuejs#8869

Author: Stanislav Lashmanov

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

@@ -37,7 +37,6 @@ import {
 } from './renderHelpers'
 import { resolveFilter } from '../helpers/resolveAssets'
 import type { InternalSlots, Slots } from '../componentSlots'
-import type { ContextualRenderFn } from '../componentRenderContext'
 import { resolveMergedOptions } from '../componentOptions'
 
 export type LegacyPublicInstance = ComponentPublicInstance &
@@ -109,9 +108,7 @@ export function installCompatInstanceProperties(map: PublicPropertiesMap) {
       const res: InternalSlots = {}
       for (const key in i.slots) {
         const fn = i.slots[key]!
-        if (!(fn as ContextualRenderFn)._ns /* non-scoped slot */) {
-          res[key] = fn
-        }
+        res[key] = fn
       }
       return res
     },

packages/vue-compat/__tests__/instance.spec.ts

@@ -284,7 +284,7 @@ describe('INSTANCE_SCOPED_SLOTS', () => {
     ).toHaveBeenWarned()
   })
 
-  test('should not include legacy slot usage in $scopedSlots', () => {
+  test('should include legacy slot usage in $scopedSlots', () => {
     let normalSlots: Slots
     let scopedSlots: Slots
     new Vue({
@@ -301,7 +301,7 @@ describe('INSTANCE_SCOPED_SLOTS', () => {
     }).$mount()
 
     expect('default' in normalSlots!).toBe(true)
-    expect('default' in scopedSlots!).toBe(false)
+    expect('default' in scopedSlots!).toBe(true)
 
     expect(
       deprecationData[DeprecationTypes.INSTANCE_SCOPED_SLOTS].message,