title: UINavigationController within ViewController, gap at top of view
body: <p>I'm working on a universal app, and I'm trying to share as much code as possible between the iPhone and iPad versions.  I need to use a TabBarController as my root view controller and though I'd like to use a SplitViewController in each of the tabs, SplitViewController's docs say it needs to be the root view controller.  So, with all of that in mind - understand that I'm attempting to place two navigation controllers side-by-side and (mostly) replicate the behavior/layout of a SplitViewController.</p>
  
  <p>Everything works just fine, except for the layout of the views.  When the app is started in portrait mode, everything functions and resizes/positions correctly when the device orientation changes.</p>
  
  <p><img src="https://i.stack.imgur.com/PQLrT.png" alt="portrait orientation"></p>
  
  <p>If the app is started in any orientation other than UIDeviceOrientationPortrait, the view displays with a 20 point gap/margin above the navigation controller.  I've tried adjusting the frame at runtime with no perfect result.  Adjusting the origin.y of the frame to -20 and increasing the height by 20 brings the view flush with the top of it's parent, but it leaves a 20 point gap at the bottom!</p>
  
  <p><img src="https://i.stack.imgur.com/DHi85.png" alt="landscape orientation"></p>