From 06f41ad9fe9de374b29be5913cb133ce10204046 Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Sat, 19 Nov 2016 21:45:37 -0500
Subject: [PATCH] avoid pushing the same ref more than once (fix #4253)

---
 src/core/vdom/modules/ref.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/vdom/modules/ref.js b/src/core/vdom/modules/ref.js
index f7cd6f14..040e8ead 100644
--- a/src/core/vdom/modules/ref.js
+++ b/src/core/vdom/modules/ref.js
@@ -32,7 +32,7 @@ export function registerRef (vnode: VNodeWithData, isRemoval: ?boolean) {
     }
   } else {
     if (vnode.data.refInFor) {
-      if (Array.isArray(refs[key])) {
+      if (Array.isArray(refs[key]) && refs[key].indexOf(ref) < 0) {
         refs[key].push(ref)
       } else {
         refs[key] = [ref]