fix(runtime-core): delete stale slots which are present but undefined (vuejs#6484)

KaelWD · lumozx · commit e3ef24faacf4 · 2023-10-21T12:05:30.000+08:00
close vuejs#9109
diff --git a/packages/runtime-core/__tests__/componentSlots.spec.ts b/packages/runtime-core/__tests__/componentSlots.spec.ts
@@ -134,9 +134,11 @@ describe('component: slots', () => {
     }
 
     const oldSlots = {
-      header: 'header'
+      header: 'header',
+      footer: undefined
     }
     const newSlots = {
+      header: undefined,
       footer: 'footer'
     }
 
diff --git a/packages/runtime-core/src/componentSlots.ts b/packages/runtime-core/src/componentSlots.ts
@@ -234,7 +234,7 @@ 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]
       }
     }

Original file line number	Diff line number	Diff line change
`@@ -234,7 +234,7 @@ export const updateSlots = (`
`234`	`234`	`// delete stale slots`
`235`	`235`	`if (needDeletionCheck) {`
`236`	`236`	`for (const key in slots) {`
`237`		`- if (!isInternalKey(key) && !(key in deletionComparisonTarget)) {`
	`237`	`+ if (!isInternalKey(key) && deletionComparisonTarget[key] == null) {`
`238`	`238`	`delete slots[key]`
`239`	`239`	`}`
`240`	`240`	`}`