From 01a0fcb876c247235610ce549313cd829ee9e65b Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Thu, 27 Sep 2018 10:23:31 -0400
Subject: [PATCH] fix: clone vnode before mutating flags

---
 packages/core/src/optional/keepAlive.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/optional/keepAlive.ts b/packages/core/src/optional/keepAlive.ts
index bd5e3355..c36fc52c 100644
--- a/packages/core/src/optional/keepAlive.ts
+++ b/packages/core/src/optional/keepAlive.ts
@@ -1,5 +1,5 @@
 import { Component, ComponentClass, MountedComponent } from '../component'
-import { VNode, Slots } from '../vdom'
+import { VNode, Slots, cloneVNode } from '../vdom'
 import { VNodeFlags } from '../flags'
 
 type MatchPattern = string | RegExp | string[] | RegExp[]
@@ -81,6 +81,11 @@ export class KeepAlive extends Component<{}, KeepAliveProps> {
     const { cache, keys } = this
     const key = vnode.key == null ? comp : vnode.key
     const cached = cache.get(key)
+
+    // clone vnode if it's reused because we are going to mutate its flags
+    if (vnode.el) {
+      vnode = cloneVNode(vnode)
+    }
     cache.set(key, vnode)
 
     if (cached) {