Demos, select validation fails on Clear

[guillaume-fr]

Official doc : https://material.angularjs.org/latest/demo/select
In the last sample (Validations), when you set a value then clic on CLEAR the select is displayed with a validation error (Required) and the label is shown two times (Top + Placeholder).

Expected result : no validation error, label only in Placeholder.

I tried to call $setPristine and $setUntouched. It fixes the validation error but the label is still here.
http://codepen.io/anon/pen/BjyzYM

[devversion]

Here is a fix for that #6132