[BUG] one time binding doesn't deal with null like value properly

[dsonet]

Vue.js version

1.0.24

Reproduction Link

http://jsbin.com/yesozewezu/1/edit?html,js,output

Steps to reproduce

For one time binding, undefined value would display as "undefined", it's different from two-way binding.

What is Expected?

Should display as empty.

What is actually happening?

Display undefined.

[LinusBorg]

Hello @dsonet,
Thank you very much for this report. We will continue this in your pull request #2989

[dsonet]

Hi @LinusBorg FYI. Just updated the reproduction case, also new fix.