Question

I am getting a crash when I popToRootViewController, this is the way I have it set up.

I have:

@property (nonatomic, retain) UIPopoverController *popover;

in dealloc:

[popover release];

when a button is pressed

if (self.popover == nil) {
    DetailViewController *detailView = [[[DetailViewController alloc] init] autorelease];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(GoToTest:) name:TestDetailPressed object:detailView];
    self.popover = [[[UIPopoverController alloc] initWithContentViewController:detailView] autorelease];
    self.popover.delegate = self;
    [self.popover presentPopoverFromRect:frame inView:self.scrollView permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
}

My DetailViewController is essentially just a UITableView. When a row is selected, I post a notification back to this current class for GoToTest:

- (void)GoToTest:(NSNotification *)notification {
    if ([self.popover isPopoverVisible]) {
        [self.popover dismisspopoverAnimated:YES];
        [self handleDismissedPopover:self.popover];
    }
    [self.navigationController popToRootViewControllerAnimated:NO];
}

- (void)handleDismissedPopover:(UIPopoverController *)popoverController {
    self.popover = nil;
    self.popover.delegate = nil;
    [[NSNotificationCenter defaultCenter] removeObserver:self name:TestDetailPressed object:nil];
}

- (void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController {
    [self handleDismissedPopover:popoverController;
}

When I run it in Instruments, I get the zombie message for

 -[UIPopoverController _popoverDismissAnimationCompleted]

and the UIViewController has a refCt of -1 at that point.

Answer 1

You probably want to change self.popover = nill to popover = nil because the first (self.popover = nil) will call the property setter, which releases the old value and sets the member to nil. Also, put the delegate nil before the property nil.

To fix, change this:

- (void)handleDismissedPopover:(UIPopoverController *)popoverController {
    self.popover = nil;
    self.popover.delegate = nil;
    [[NSNotificationCenter defaultCenter] removeObserver:self name:TestDetailPressed object:nil];
}

To:

- (void)handleDismissedPopover:(UIPopoverController *)popoverController {
    popover.delegate = nil;
    popover = nil;
    [[NSNotificationCenter defaultCenter] removeObserver:self name:TestDetailPressed object:nil];
}

---

And if that doesn’t work, set NSZombieEnabled, MallocStackLogging, and guard malloc in the debugger. Then, when your App crashes, type this in the gdb console:

(gdb) info malloc-history 0x543216

Replace 0x543216 with the address of the object that caused the crash, and you will get a much more useful stack trace and it should help you pinpoint the exact line in your code that is causing the problem.

See this article for more detailed instructions.