From b3c3e52979d6d4b0312a3257474c15e903096062 Mon Sep 17 00:00:00 2001
From: haiweilian <haiweilian@foxmail.com>
Date: Tue, 20 Dec 2022 14:22:40 +0800
Subject: [PATCH] fix(runtime-core): delete undefined stale slots

---
 .../__tests__/componentSlots.spec.ts          | 28 +++++++++++++++++++
 packages/runtime-core/src/componentSlots.ts   |  2 +-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/packages/runtime-core/__tests__/componentSlots.spec.ts b/packages/runtime-core/__tests__/componentSlots.spec.ts
index 9248a8e6afe..fa6681a7125 100644
--- a/packages/runtime-core/__tests__/componentSlots.spec.ts
+++ b/packages/runtime-core/__tests__/componentSlots.spec.ts
@@ -167,6 +167,34 @@ describe('component: slots', () => {
     expect(instance.slots.footer()).toMatchObject([normalizeVNode('footer')])
   })
 
+  test('updateSlots: instance.slots should be updated correctly (when slotType becomes null)', async () => {
+    const flag1 = ref(true)
+
+    let instance: any
+    const Child = () => {
+      instance = getCurrentInstance()
+      return 'child'
+    }
+
+    const Comp = {
+      setup() {
+        return () => [
+          h(Child, null, {
+            default: flag1.value ? () => 'default' : null
+          })
+        ]
+      }
+    }
+    render(h(Comp), nodeOps.createElement('div'))
+
+    expect(instance.slots).toHaveProperty('default')
+
+    flag1.value = false
+    await nextTick()
+
+    expect(instance.slots).not.toHaveProperty('default')
+  })
+
   test('updateSlots: instance.slots should be update correctly (when vnode.shapeFlag is not SLOTS_CHILDREN)', async () => {
     const flag1 = ref(true)
 
diff --git a/packages/runtime-core/src/componentSlots.ts b/packages/runtime-core/src/componentSlots.ts
index 682a107e676..dc948694f7e 100644
--- a/packages/runtime-core/src/componentSlots.ts
+++ b/packages/runtime-core/src/componentSlots.ts
@@ -204,7 +204,7 @@ export const updateSlots = (
   // delete stale slots
   if (needDeletionCheck) {
     for (const key in slots) {
-      if (!isInternalKey(key) && !(key in deletionComparisonTarget)) {
+      if (!isInternalKey(key) && deletionComparisonTarget[key] == null) {
         delete slots[key]
       }
     }