[2.0] v-once and v-for don't seem to play nice together #3155
Description
Vue.js version
2.x
Reproduction Link
https://jsfiddle.net/0jjufkpb/
Steps to reproduce
Just run the fiddle.
What is Expected?
arr is iterated, each item and its type (string) are displayed.
What is actually happening?
Items are lost (typeof returns undefined).
Will look deeper into this. If @yyx990803 could give a hint – or clarify that this is the expected behavior somehow – that would be great.