From ad844cf1e767137a713f715779969ffb94207c7a Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Mon, 7 Jun 2021 11:04:41 -0400
Subject: [PATCH] fix(compat): revert private properties on $options in comapt
 mode

fix #3883
---
 packages/runtime-core/src/compat/instance.ts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/packages/runtime-core/src/compat/instance.ts b/packages/runtime-core/src/compat/instance.ts
index 39f27f59..cc903956 100644
--- a/packages/runtime-core/src/compat/instance.ts
+++ b/packages/runtime-core/src/compat/instance.ts
@@ -37,6 +37,7 @@ import {
 import { resolveFilter } from '../helpers/resolveAssets'
 import { InternalSlots, Slots } from '../componentSlots'
 import { ContextualRenderFn } from '../componentRenderContext'
+import { resolveMergedOptions } from '../componentOptions'
 
 export type LegacyPublicInstance = ComponentPublicInstance &
   LegacyPublicProperties
@@ -127,6 +128,15 @@ export function installCompatInstanceProperties(map: PublicPropertiesMap) {
       // needed by many libs / render fns
       $vnode: i => i.vnode,
 
+      // inject addtional properties into $options for compat
+      // e.g. vuex needs this.$options.parent
+      $options: i => {
+        const res = extend({}, resolveMergedOptions(i))
+        res.parent = i.proxy!.$parent
+        res.propsData = i.vnode.props
+        return res
+      },
+
       // some private properties that are likely accessed...
       _self: i => i.proxy,
       _uid: i => i.uid,