CALayer position contains NaN: [nan -0.5]

Question

I see this log in the console when I run my app:
CALayer position contains NaN: [nan -0.5]

The app consists of a UITabar of which the first tab is a UINavController. In the NavController I'm launching the AddressBookPicker. In the Addressbook picker I'm only choosing to show phone numbers.

When I choose on a contact that has only email addresses, that is when I see this log.

I do not see any crashes or any issues for that matter, just the log printed onto the console. Want to make sure that this is not a hidden issue that crashes on me after the launch.

Below is a snippet of relevant code and the stacktrace. Not sure which other parts of the code to paste here, please let me know if there are any I can post that might help.

Any help/inputs appreciated.

Thanks!

Code

ABPeoplePickerNavigationController *picker = [[ABPeoplePickerNavigationController alloc] init];

NSArray *displayedItems = [NSArray arrayWithObjects: [NSNumber numberWithInt:kABPersonPhoneProperty]), nil];

picker.displayedProperties = displayedItems;

picker.peoplePickerDelegate = self;

[self presentModalViewController:picker animated:YES];

Stacktrace

#0    0x00096377 in NSLog

#1    0x046b38c9 in CALayerSetPosition

#2    0x046b3846 in -[CALayer setPosition:]

#3    0x046b375f in -[CALayer setFrame:]

#4    0x002f510b in -[UIView(Geometry) setFrame:]

#5    0x003dbe6d in -[UILabel setFrame:]

#6    0x023ed095 in -[ABPersonTableViewDataSource reloadNoValueLabelAnimated:]

#7    0x0244cf53 in -[ABPersonTableViewDataSource reloadDataIncludingHeaderView:invalidatePropertyData:]

#8    0x023f30d4 in -[ABPersonTableViewDataSource reloadDataIncludingHeaderView:]

#9    0x023eabc9 in -[ABPersonViewControllerHelper prepareViewWithDisplayedProperties:person:allowActions:]

#10    0x023ea6bc in -[ABPersonViewControllerHelper loadViewWithDisplayedProperties:person:allowDeletion:allowActions:]

#11    0x023ea598 in -[ABPersonViewController loadView]

#12    0x0036a54f in -[UIViewController view]

#13    0x003689f4 in -[UIViewController contentScrollView]

#14    0x003787e2 in -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:]

#15    0x00376ea3 in -[UINavigationController _layoutViewController:]

#16    0x0037812d in -[UINavigationController _startTransition:fromViewController:toViewController:]

#17    0x00372ccd in -[UINavigationController _startDeferredTransitionIfNeeded]

#18    0x00379d8b in -[UINavigationController pushViewController:transition:forceImmediate:]

#19    0x00372b67 in -[UINavigationController pushViewController:animated:]

#20    0x02403bc2 in -[ABPeoplePickerNavigationController pushViewController:animated:]

#21    0x0242a424 in -[ABPeoplePickerNavigationController showCardForPerson:withMemberCell:animate:forceDisableEditing:personViewController:]

#22    0x0242ce20 in -[ABMembersViewController showCardForPerson:withMemberCell:animate:]

#23    0x0240a0ef in -[ABMembersController abDataSource:selectedPerson:atIndexPath:withMemberCell:animate:]

#24    0x023fdb47 in -[ABMembersDataSource tableView:didSelectRowAtIndexPath:]

#25    0x00333a48 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:]

#26    0x0032a32e in -[UITableView _userSelectRowAtIndexPath:]

#27    0x0003f21a in __NSFireDelayedPerform

#28    0x02631f73 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__

#29    0x026335b4 in __CFRunLoopDoTimer

#30    0x0258fdd9 in __CFRunLoopRun

#31    0x0258f350 in CFRunLoopRunSpecific

#32    0x0258f271 in CFRunLoopRunInMode

#33    0x02f2f00c in GSEventRunModal

#34    0x02f2f0d1 in GSEventRun

#35    0x002ceaf2 in UIApplicationMain

#36    0x00002554 in main at main.m:14

Answer 1

1. I don't know.

2. I see this too - I am doing something completely different from you - I am using the route-me mapping engine to display scrollable maps.

I believe it has something to do with scrolling views - and a layer somehow involved in the scrolling. As some of the views you mentioned I believe are scrolling - this would concur with my observations.

I wish I had more data for you, but one thing I can tell you is that I have been working on the app for months, and have been testing it on the iPhone and iPad, devices and simulator, under OSes 3.2 and 4.0 - and have had no crashes or memory leaks [at all, or associated with this].

So in short - no idea - but I think you're okay!