fix(runtime-core): should not track dynamic children when the user calls a compiled slot inside template expression (#3554)

fix #3548, partial fix for #3569

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

@@ -37,6 +37,7 @@ import {
 import { resolveFilter } from '../helpers/resolveAssets'
 import { resolveMergedOptions } from '../componentOptions'
 import { InternalSlots, Slots } from '../componentSlots'
+import { ContextualRenderFn } from '../componentRenderContext'
 
 export type LegacyPublicInstance = ComponentPublicInstance &
   LegacyPublicProperties
@@ -106,7 +107,7 @@ export function installCompatInstanceProperties(map: PublicPropertiesMap) {
       const res: InternalSlots = {}
       for (const key in i.slots) {
         const fn = i.slots[key]!
-        if (!(fn as any)._nonScoped) {
+        if (!(fn as ContextualRenderFn)._ns /* non-scoped slot */) {
           res[key] = fn
         }
       }

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

@@ -281,7 +281,7 @@ function convertLegacySlots(vnode: VNode): VNode {
       for (const key in slots) {
         const slotChildren = slots[key]
         slots[key] = () => slotChildren
-        slots[key]._nonScoped = true
+        slots[key]._ns = true /* non-scoped slot */
       }
     }
   }