fix(runtime-core): KeepAlive/BeseTransition should work with setScopeId + slot

packages/runtime-core/__tests__/components/BaseTransition.spec.ts

@@ -10,7 +10,8 @@ import {
   serialize,
   VNodeProps,
   KeepAlive,
-  TestElement
+  TestElement,
+  withScopeId
 } from '@vue/runtime-test'
 
 function mount(
@@ -1090,5 +1091,34 @@ describe('BaseTransition', () => {
     test('w/ KeepAlive', async () => {
       await runTestWithKeepAlive(testInOutBeforeFinish)
     })
+
+    // #2892
+    test('should work with slots + scopeId', async () => {
+      const withChildId = withScopeId('foo')
+      const withRootId = withScopeId('root')
+
+      const Child = {
+        render: withChildId(function(this: any) {
+          return h(BaseTransition, null, {
+            default: withChildId(() =>
+              h('div', null, h('div', this.$slots.default()))
+            )
+          })
+        })
+      }
+
+      const App = {
+        render: withRootId(() =>
+          h(Child, null, {
+            default: withRootId(() => h('div'))
+          })
+        )
+      }
+      const root = nodeOps.createElement('div')
+      render(h(App), root)
+      expect(serializeInner(root)).toBe(
+        `<div foo root><div foo><div root foo-s></div></div></div>`
+      )
+    })
   })
 })

packages/runtime-core/__tests__/components/KeepAlive.spec.ts

@@ -825,4 +825,32 @@ describe('KeepAlive', () => {
     await nextTick()
     expect(serializeInner(root)).toBe(`<div foo>changed</div>`)
   })
+
+  // #2892
+  test('should work with slots + scopeId', async () => {
+    const withChildId = withScopeId('foo')
+    const withRootId = withScopeId('root')
+
+    const Child = {
+      render: withChildId(function(this: any) {
+        return h(KeepAlive, null, {
+          default: withChildId(() =>
+            h('div', null, h('div', this.$slots.default()))
+          )
+        })
+      })
+    }
+
+    const App = {
+      render: withRootId(() =>
+        h(Child, null, {
+          default: withRootId(() => h('div'))
+        })
+      )
+    }
+    render(h(App), root)
+    expect(serializeInner(root)).toBe(
+      `<div foo root><div foo><div root foo-s></div></div></div>`
+    )
+  })
 })

packages/runtime-core/src/renderer.ts

@@ -805,13 +805,13 @@ function baseCreateRenderer(
       hostSetScopeId(el, scopeId)
     }
     if (parentComponent) {
-      const treeOwnerId = parentComponent.type.__scopeId
+      let subTree = parentComponent.subTree
+      const treeOwnerId = subTree.scopeId
       // vnode's own scopeId and the current patched component's scopeId is
       // different - this is a slot content node.
       if (treeOwnerId && treeOwnerId !== scopeId) {
         hostSetScopeId(el, treeOwnerId + '-s')
       }
-      let subTree = parentComponent.subTree
       if (__DEV__ && subTree.type === Fragment) {
         subTree =
           filterSingleRoot(subTree.children as VNodeArrayChildren) || subTree