select(multiple): adding one resets pristine to true

[Gbacc]

Ok this is my first message here.

Using lastest version of angularjs/material , it seems i found out an issue using md-select.

See this jsfiddle : http://jsfiddle.net/ypjgdzxp/3/

What you can see here is that i'm adding rows on the fly wich contains an md-select. The problem is that adding a new md-select to the Dom resets the form pristine to true , even if it was false/dirty before.
In my exemple , juste put anything in the upper input "Nom de couche" wich will make the form dirty , then add a new row using the "+" button at the bottom.

[devversion]

Hello, just got into this.

At the first, after querying the git logs I found the commit. which introduced the issue. See 09bd5a3

I created a PR which fixes that #6782

[cstephe]

I'm a bit confused on this, the commit which keeps being referenced as a fix is actually the cause of the issue, it attempts to fix the issue by causing a side effect on the form. It tries to mitigate the side effect by making a bad assumption that adding to a form with a value set at creation means the form should be clean. Which maybe a 50%+ case for uses but I think there is a very large gap of use cases which this is very bad.