UIImagePickerController crash only on iOS 7 - iPad

Question

I'm getting hundreds of crashes from one of my live apps ever since people started upgrading to iOS 7. Has anyone else seen this problem? Nothing reproduces on my iPad 3 with iOS 7...

Link to Crashlytics: crashes.to/s/edf2e71d9a5

Fatal Exception CALayerInvalidGeometry
CALayer position contains NaN: [nan nan]
0 ...    CoreFoundation  __exceptionPreprocess + 130
2    CoreFoundation  -[NSException initWithCoder:]
3    QuartzCore      CA::Layer::set_position(CA::Vec2<double> const&, bool) + 242
4    QuartzCore  -[CALayer setPosition:] + 54
5    QuartzCore  -[CALayer setFrame:] + 594
6    UIKit   -[UIView(Geometry) setFrame:] + 254
7    UIKit   -[UILabel setFrame:] + 138
8    UIKit   -[UINavigationItemView initWithNavigationItem:] + 384
9    UIKit   -[UINavigationItem _titleView] + 92
10   UIKit   -[UINavigationBar _prepareForPushAnimationWithItems:] + 68
11   UIKit   -[UINavigationBar pushNavigationItem:] + 292
12   UIKit   -[UINavigationBar _pushNavigationItem:transition:] + 386
13   UIKit   __71-[UINavigationController pushViewController:transition:forceImmediate:]_block_invoke + 150
14   UIKit   -[UINavigationController pushViewController:transition:forceImmediate:] + 1384
15   UIKit   -[UINavigationController pushViewController:animated:] + 294
16   UIKit   -[UIImagePickerController _setupControllersForCurrentSourceType] + 112
17   UIKit   -[UIImagePickerController setSourceType:] + 456
18 ...   libdispatch.dylib   _dispatch_call_block_and_release + 10
19   libdispatch.dylib   _dispatch_client_callout + 22
20   libdispatch.dylib   _dispatch_main_queue_callback_4CF$VARIANT$mp + 268
21   CoreFoundation  __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
22   CoreFoundation  __CFRunLoopRun + 1300
23   CoreFoundation  CFRunLoopRunSpecific + 522
24   CoreFoundation  CFRunLoopRunInMode + 106
25   GraphicsServices    GSEventRunModal + 138
26   UIKit   UIApplicationMain + 1136

Answer 1

Collectively we've come to the conclusion that this is a bug in iOS 7 on iPad. It occurs when you attempt to show a UIImagePickerController in a UIPopoverControl from a UIBarButtonItem for the first time. After the user grants permission to their photo album the crash happens. It appears the solution for now is to request permission to photos before opening the UIPopoverControl. Here is how I implemented my solution:

// Photo Library
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary])
{
    void(^blk)() =  ^() {
        UIImagePickerController* picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        if (NIIsPad()) {
            UIPopoverController* popover = [[UIPopoverController alloc] initWithContentViewController:picker];
            [popover presentPopoverFromBarButtonItem:self.popoverAnchor permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
        } else {
            [self.navigationController presentModalViewController:picker animated:YES];
        }
    };

    // Make sure we have permission, otherwise request it first
    ALAssetsLibrary* assetsLibrary = [[ALAssetsLibrary alloc] init];
    ALAuthorizationStatus authStatus;
    if (IOS_VERSION_GREATER_THAN_OR_EQUAL_TO(@"6.0"))
        authStatus = [ALAssetsLibrary authorizationStatus];
    else
        authStatus = ALAuthorizationStatusAuthorized;

    if (authStatus == ALAuthorizationStatusAuthorized) {
        blk();
    } else if (authStatus == ALAuthorizationStatusDenied || authStatus == ALAuthorizationStatusRestricted) {
        [[UIAlertView alertViewWithTitle:@"Grant photos permission" message:@"Grant permission to your photos. Go to Settings App > Privacy > Photos."] show];
    } else if (authStatus == ALAuthorizationStatusNotDetermined) {
        [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
            // Catch the final iteration, ignore the rest
            if (group == nil)
                dispatch_async(dispatch_get_main_queue(), ^{
                    blk();
                });
            *stop = YES;
        } failureBlock:^(NSError *error) {
            // failure :(
            dispatch_async(dispatch_get_main_queue(), ^{
                [[UIAlertView alertViewWithTitle:@"Grant photos permission" message:@"Grant permission to your photos. Go to Settings App > Privacy > Photos."] show];
            });
        }];
    }
}

Don't forget to add AssetsLibrary.framework to your project.