title: Crash with custom segue
body: <p>I create a custom segue:</p>
  
  <pre><code>-(void)perform{
  
  UIViewController *destination = [self destinationViewController];
  UIViewController *source = [self sourceViewController];
  
  [source.view addSubview:destination.view];
  
  CGRect destionationFrame = destination.view.frame;
  CGRect sourceFrame = source.view.frame;
  CGSize sourceSize = CGSizeMake(sourceFrame.size.height, sourceFrame.size.width);
  
  destination.view.frame = CGRectMake(sourceSize.width,0,destionationFrame.size.width,destionationFrame.size.height);
  
  [UIView animateWithDuration:0.3
                        delay:0
                      options:UIViewAnimationCurveEaseInOut | UIViewAnimationOptionBeginFromCurrentState
                   animations:^{
                       destination.view.frame = CGRectMake(sourceSize.width-destionationFrame.size.width,0,destionationFrame.size.width,destionationFrame.size.height);
                   } completion:^(BOOL finished) {
                       //[source presentModalViewController:destination animated:NO completion:nil];
                       //[source presentModalViewController:destination animated:NO];
                   }];
  
  }
  </code></pre>
  
  <p>The problem is that, if i do nothing when the animation is finished, touching any controls of destination controller causes app crash.</p>
  
  <p>If i make a presentModalViewController causes that any object on the screen responds.</p>
  
  <p>Any help? Thanks</p>