title: ngOptions result in options with wrong values
body: <p>I'm trying to render select box and it does not work as expected - options values are incorrect. I checked <a href="http://docs.angularjs.org/api/ng.directive%3aselect">manual</a>, according to it the syntax for array (in my case array of objects) is</p>
  
  <pre><code>select as label for value in array
  </code></pre>
  
  <p>So here is what i'm doing:</p>
  
  <p>data:</p>
  
  <pre><code>[{"id":"3","name":"asdasd","code":"asdads","group":"2","cost":"0"},{"id":"4","name":"adrf fg df ","code":"dasfasd","group":"2","cost":"0"}]
  </code></pre>
  
  <p>template:</p>
  
  <pre><code>&lt;select ng-model="productToBuy" ng-options="item.id as item.id for item in products"&gt;&lt;/select&gt;
  </code></pre>
  
  <p>rendered result:</p>
  
  <pre><code>&lt;select ng-model="productToBuy" ng-options="item.id as item.id for item in products" class="ng-pristine ng-valid"&gt;
      &lt;option value="0" selected="selected"&gt;3&lt;/option&gt;
      &lt;option value="1"&gt;4&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>as we can see, options values does not set to items's id.</p>
  
  <p>Also this may be not proper syntax when source is array but i having same results when trying like this:</p>
  
  <pre><code>&lt;select ng-model="productToBuy" ng-options="item.id as item.id for (key, item) in products"&gt;&lt;/select&gt;
  </code></pre>
  
  <p>I put this code on <a href="http://jsfiddle.net/ADukg/1547/">jsfiddle</a>. Any help appreciated.</p>