title: Why does CGPDFPageGetDrawingTransform() crash with SIGABRT when specifying a rotation?
body: <p>When I call CGPDFPageGetDrawingTransform() with a rotation argument, the application crashes. If I specify no rotation, there is no crash.</p>
  
  <p>Here is my drawLayer:inContext: method:</p>
  
  <pre><code>- (void)drawLayer:(CALayer*)layer inContext:(CGContextRef)context
  {
  CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0);
      CGRect boundingBox = CGContextGetClipBoundingBox(context); 
      CGContextFillRect(context, boundingBox);
  
      //convert to UIKit native coodinate system
      CGContextTranslateCTM(context, 0.0, self.bounds.size.height);
  CGContextScaleCTM(context, 1.0, -1.0);
  
      //Rotate the pdf_page
      CGAffineTransform pfd_transform = CGPDFPageGetDrawingTransform(self.page, kCGPDFCropBox, self.frame, 58.46f, true);
  
      CGContextSaveGState (context);
      CGContextConcatCTM (context, pfd_transform);
      CGContextClipToRect (context, self.frame);
      CGContextDrawPDFPage (context, self.page);
      CGContextRestoreGState (context);
  }
  </code></pre>
  
  <p>In the long run, I would like to rotate the pdf dynamically to follow a users heading. Maybe I am going at this all wrong... </p>
  
  <p>Thank you for your time.</p>