title: setContentViewController method in popover iOS8 causes app crash
body: <p>The setContentViewController method in UIPopoverController seems to be causing an app crash in iOS 8. Just wondering if anybody else also faced this issue in iOS 8. This works without any issue in iOS 7.</p>
  
  <p>The error pointed in the exception seems to be misleading as it states that the setContentViewController should be called after presenting the popover</p>
  
  <pre><code>- (void)buttonPressed {
  
  UIViewController *tableViewController = [UIViewController new];
  
  if(_popover == nil){
  
      _popover = [[UIPopoverController alloc] initWithContentViewController:tableViewController];
  
      [_popover presentPopoverFromRect:CGRectMake(self.textField.frame.size.width / 2, self.textField.frame.size.height / 1, 1, 1) inView:self.textField permittedArrowDirections:UIPopoverArrowDirectionLeft animated:YES];
  }else{
      [_popover setContentViewController:tableViewController];
  }    
  </code></pre>
  
  <p>}</p>
  
  <p>Here is Stack trace from the crash,</p>
  
  <pre><code>2014-09-11 16:48:39.904 iOS 8 Rotation[3969:67869] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIPopoverController setContentViewController:animated:] can only be called after the popover has been presented.'
  *** First throw call stack:
  (
      0   CoreFoundation                      0x01c79df6 __exceptionPreprocess + 182
      1   libobjc.A.dylib                     0x01903a97 objc_exception_throw + 44
      2   CoreFoundation                      0x01c79d1d +[NSException raise:format:] + 141
      3   UIKit                               0x00b1946f -[UIPopoverPresentationController _setContentViewController:animated:] + 89
      4   UIKit                               0x009bb1b4 -[UIPopoverController setContentViewController:animated:] + 155
      5   UIKit                               0x009bb114 -[UIPopoverController setContentViewController:] + 48
      6   iOS 8 Rotation                      0x00046ca5 -[MianViewController buttonPressed] + 933
      7   libobjc.A.dylib                     0x019197cd -[NSObject performSelector:withObject:withObject:] + 84
      8   UIKit                               0x002ef79d -[UIApplication sendAction:to:from:forEvent:] + 99
      9   UIKit                               0x002ef72f -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 64
      10  UIKit                               0x00422a16 -[UIControl sendAction:to:forEvent:] + 69
      11  UIKit                               0x00422e33 -[UIControl _sendActionsForEvents:withEvent:] + 598
      12  UIKit                               0x0042209d -[UIControl touchesEnded:withEvent:] + 660
      13  UIKit                               0x0033faba -[UIWindow _sendTouchesForEvent:] + 874
      14  UIKit                               0x00340595 -[UIWindow sendEvent:] + 791
      15  UIKit                               0x00305aa9 -[UIApplication sendEvent:] + 242
      16  UIKit                               0x003158de _UIApplicationHandleEventFromQueueEvent + 20690
      17  UIKit                               0x002ea079 _UIApplicationHandleEventQueue + 2206
      18  CoreFoundation                      0x01b9d7bf __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
      19  CoreFoundation                      0x01b932cd __CFRunLoopDoSources0 + 253
      20  CoreFoundation                      0x01b92828 __CFRunLoopRun + 952
      21  CoreFoundation                      0x01b921ab CFRunLoopRunSpecific + 443
      22  CoreFoundation                      0x01b91fdb CFRunLoopRunInMode + 123
      23  GraphicsServices                    0x040cc24f GSEventRunModal + 192
      24  GraphicsServices                    0x040cc08c GSEventRun + 104
      25  UIKit                               0x002ede16 UIApplicationMain + 1526
      26  iOS 8 Rotation                      0x0004774d main + 141
      27  libdyld.dylib                       0x0224cac9 start + 1
      28  ???                                 0x00000001 0x0 + 1
  )
  libc++abi.dylib: terminating with uncaught exception of type NSException
  </code></pre>