2.0 examples/tree/index.html can not add more than one child

[taowen]

vue.js:2113 [Vue warn]: Error during component render (found in component: <item>)warn @ vue.js:2113get @ vue.js:627run @ vue.js:716runSchedulerQueue @ vue.js:531flushSchedulerQueue @ vue.js:500nextTickHandler @ vue.js:336
vue.js:570 Uncaught NotFoundError: Failed to execute 'insertBefore' on 'Node': The node before which the new node is to be inserted is not a child of this node.

This is the error from console

Code from next branch

dist/vue.js built from npm

[yyx990803]

Current dist file is out of date, please wait util an actual release.