title: viewWillTransitionToSize coordinator ignores block
body: <p>Tried gaming the new rotation methods, I need to know if the device is being rotated in order to defer and cancel an action that is not required in the event of rotation.</p>
  
  <pre><code>-(void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id&lt;UIViewControllerTransitionCoordinator&gt;)coordinator
  {
      [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
  
      _rotating = YES;
  
      [coordinator notifyWhenInteractionEndsUsingBlock:^(id&lt;UIViewControllerTransitionCoordinatorContext&gt; context) {
          _rotating = NO;
      }];
  }
  </code></pre>
  
  <p>Seems straight forward and should work based on my interpretation of the documentation but apparently no. It seems that _rotating is set to YES and never gets set back to NO. Consequently, it seems my completion block is never called. </p>