title: ng-repeat does not work when array (or string) has non-unique values
body: <p>I have this line of code in my AngularJS template:</p>
  
  <pre><code>        &lt;span ng-repeat="letter in word"&gt;{{letter}}&amp;nbsp;&lt;/span&gt;
  </code></pre>
  
  <p>'word' is a string. 
  It works fine unless word contains the same letter twice. For example for the word 'boy' it works fine and renders the string "b o y ", but for the words 'ball' or 'elephant' nothing is rendered. The same problem occurs when iterating over an array of one letter strings.</p>
  
  <p>Any ideas?</p>