fix: should consider presence of normal slots when caching normalized scoped slots

fix #9644

Author: yyx990803

src/core/vdom/helpers/normalize-scoped-slots.js

@@ -11,6 +11,7 @@ export function normalizeScopedSlots (
 ): any {
   let res
   const isStable = slots ? !!slots.$stable : true
+  const hasNormalSlots = Object.keys(normalSlots).length > 0
   const key = slots && slots.$key
   if (!slots) {
     res = {}
@@ -22,7 +23,8 @@ export function normalizeScopedSlots (
     prevSlots &&
     prevSlots !== emptyObject &&
     key === prevSlots.$key &&
-    Object.keys(normalSlots).length === 0
+    !hasNormalSlots &&
+    !prevSlots.$hasNormal
   ) {
     // fast path 2: stable scoped slots w/ no normal slots to proxy,
     // only need to normalize once
@@ -48,6 +50,7 @@ export function normalizeScopedSlots (
   }
   def(res, '$stable', isStable)
   def(res, '$key', key)
+  def(res, '$hasNormal', hasNormalSlots)
   return res
 }
 

test/unit/features/component/component-scoped-slot.spec.js

@@ -1227,4 +1227,41 @@ describe('Component scoped slot', () => {
       expect(vm.$el.textContent.trim()).toBe(`2`)
     }).then(done)
   })
+
+  // #9644
+  it('should factor presence of normal slots into scoped slots caching', done => {
+    const Wrapper = {
+      template: `<div>
+        <p>Default:<slot/></p>
+        <p>Content:<slot name='content'/></p>
+      </div>`
+    }
+
+    const vm = new Vue({
+      data: { ok: false },
+      components: { Wrapper },
+      template: `<wrapper>
+        <p v-if='ok'>ok</p>
+        <template #content>
+          <p v-if='ok'>ok</p>
+        </template>
+      </wrapper>`
+    }).$mount()
+
+    expect(vm.$el.textContent).not.toMatch(`Default:ok`)
+    expect(vm.$el.textContent).not.toMatch(`Content:ok`)
+    vm.ok = true
+    waitForUpdate(() => {
+      expect(vm.$el.textContent).toMatch(`Default:ok`)
+      expect(vm.$el.textContent).toMatch(`Content:ok`)
+      vm.ok = false
+    }).then(() => {
+      expect(vm.$el.textContent).not.toMatch(`Default:ok`)
+      expect(vm.$el.textContent).not.toMatch(`Content:ok`)
+      vm.ok = true
+    }).then(() => {
+      expect(vm.$el.textContent).toMatch(`Default:ok`)
+      expect(vm.$el.textContent).toMatch(`Content:ok`)
+    }).then(done)
+  })
 })