Vue.js version

v2.2.0-beta.1

Reproduction Link

2.2.0-beta.1 - https://jsfiddle.net/sqal/4us41rdz/1/
2.1.10 - https://jsfiddle.net/sqal/1zgatz1b/

Steps to reproduce

• open 2.2.0-beta.1 repo link
• type something in the first input field - value prop in the parent component should update

What is Expected?

v-model should work regardless of the name of passed prop.

What is actually happening?

When v-model prop name is "value"', v-model doesn't update the data when input event is fired. It ony breaks when is used on custom component. It worked fine in 2.1.10.