tweak

src/runtime/instance/render.js

@@ -38,9 +38,8 @@ export function renderMixin (Vue) {
       return
     }
     // check props
-    const props = this.$options.props
-    if (props && data && data.attrs) {
-      for (let key in props) {
+    if (data && data.attrs) {
+      for (let key in this.$options.props) {
         let oldVal = this[key]
         let newVal = data.attrs[key] || data.attrs[hyphenate(key)]
         if (oldVal !== newVal) {