title: Angular JS $on "$locationChangeStart" triggered twice when event.preventDefault()
body: <p>I'm trying to listen to the $on "$locationChangeStart" event in Angular JS and prevent the event from happening under certain circumstances.
  As soon as I do event.preventDefault(), the $on "$locationChangeStart" event gets fired again.
  Is that a Angular JS Bug?</p>
  
  <pre><code>$rootScope.$on "$locationChangeStart", (event, next, current) -&gt;
    if doNotLeave
      event.preventDefault()
  </code></pre>
  
  <p>Thanks in advance,
  Steff</p>