Crash Changing Tab from Sidebar

[NilsBerni]

Steps to reproduce:

1. Enter full screen.
2. Collapse the sidebar by dragging it all the way to the left.
3. Let the mouse go.
4. Move the mouse left until the sidebar appears as overlay.
5. Select another sidebar tab -> crash

https://user-images.githubusercontent.com/30769791/128616212-2d1c921c-0c78-4f54-974c-f97fda512ff4.mov

Thread 1: EXC_BREAKPOINT (code=1, subcode=0x1a4503df8) UniversalNavigationMacOS[5637:310422] [General] *** -[NSArray objectsAtIndexes:]: index 18446744073709551615 in index set beyond bounds for empty array 2021-08-08 01:26:49.544980+0200 UniversalNavigationMacOS[5637:310422] [General] ( 0 CoreFoundation 0x00000001a19f8c78 __exceptionPreprocess + 240 1 libobjc.A.dylib 0x00000001a17210a8 objc_exception_throw + 60 2 CoreFoundation 0x00000001a1ac3b68 -[__NSCFString characterAtIndex:].cold.1 + 0 3 CoreFoundation 0x00000001a1982d44 -[NSArray objectsAtIndexes:] + 752 4 AppKit 0x00000001a41f539c -[NSSplitView _sortSubviews] + 256 5 AppKit 0x00000001a41f51e4 -[NSSplitView addSubview:] + 68 6 AppKit 0x00000001a424ab08 -[NSSplitView(NSSplitViewArrangedSubviews) insertArrangedSubview:atIndex:] + 452 7 AppKit 0x00000001a41f6324 -[NSSplitViewController _updateSplitView:withBlock:] + 68 8 AppKit 0x00000001a43c11c0 -[NSSplitViewController insertArrangedView:atIndex:] + 172 9 AppKit 0x00000001a43c10f0 -[NSSplitViewController insertWrapperViewIntoSplitViewForSplitViewItem:atIndex:] + 104 10 AppKit 0x00000001a41f441c -[NSSplitViewController insertSplitViewItem:atIndex:] + 632 11 SwiftUI 0x00000001c29a75b8 $s7SwiftUI38NotificationSendingSplitViewControllerC06inserteF4Item_2atySo07NSSplitfI0C_SitF + 416 12 SwiftUI 0x00000001c29a7640 $s7SwiftUI38NotificationSendingSplitViewControllerC06inserteF4Item_2atySo07NSSplitfI0C_SitFTo + 68 13 SwiftUI 0x00000001c27d9b98 $sSo21NSSplitViewControllerC7SwiftUIE07replacebC02at4withySi_So06NSViewC0CtF + 336 14 SwiftUI 0x00000001c27d9efc $s7SwiftUI22AppKitNavigationBridgeC13dismissDetail33_7420C33EDE6D7EA74A00CE41E680CEAELLyyF + 400 15 SwiftUI 0x00000001c27d8a0c $s7SwiftUI22AppKitNavigationBridgeC20preferencesDidChangeyyAA14PreferenceListVF + 256 16 SwiftUI 0x00000001c292dbe4 $s7SwiftUI13NSHostingViewC20preferencesDidChangeyyF + 732 17 SwiftUI 0x00000001c2304c8c $s7SwiftUI9ViewGraphC13updateOutputs2atyAA4TimeV_tF + 176 18 SwiftUI 0x00000001c28f20f4 $s7SwiftUI16ViewRendererHostPAAE6render8interval17updateDisplayListySd_SbtFyyXEfU + 1428 19 SwiftUI 0x00000001c28eaeb8 $s7SwiftUI16ViewRendererHostPAAE6render8interval17updateDisplayListySd_SbtF + 268 20 SwiftUI 0x00000001c2928314 $s7SwiftUI13NSHostingViewC6layoutyyFySo18NSAnimationContextCXEfU + 220 21 SwiftUI 0x00000001c2931050 $sSo18NSAnimationContextCIgg_ABIegg_TRTA + 28 22 SwiftUI 0x00000001c2925cb8 $sSo18NSAnimationContextCIegg_ABIyBy_TR + 44 23 AppKit 0x00000001a4183fa8 +[NSAnimationContext runAnimationGroup:] + 72 24 SwiftUI 0x00000001c29281e4 $s7SwiftUI13NSHostingViewC6layoutyyF + 316 25 SwiftUI 0x00000001c29284bc $s7SwiftUI13NSHostingViewC6layoutyyFTo + 28 26 AppKit 0x00000001a41c1a6c _NSViewLayout + 728 27 AppKit 0x00000001a41c14b0 -[NSView _layoutSubtreeWithOldSize:] + 408 28 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 29 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 30 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 31 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 32 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 33 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 34 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 35 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 36 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 37 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 38 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 39 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 40 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 41 AppKit 0x00000001a41c1628 -[NSView _layoutSubtreeWithOldSize:] + 784 42 AppKit 0x00000001a41c08fc -[NSView _layoutSubtreeIfNeededAndAllowTemporaryEngine:] + 996 43 AppKit 0x00000001a41c0444 -[NSWindow(NSConstraintBasedLayout) _layoutViewTree] + 148 44 AppKit 0x00000001a423c728 -[NSWindow(NSConstraintBasedLayout) layoutIfNeeded] + 308 45 AppKit 0x00000001a423c51c __NSWindowGetDisplayCycleObserverForLayout_block_invoke + 436 46 AppKit 0x00000001a423b71c NSDisplayCycleObserverInvoke + 188 47 AppKit 0x00000001a423b298 NSDisplayCycleFlush + 832 48 QuartzCore 0x00000001a7c10954 _ZN2CA11Transaction19run_commit_handlersE18CATransactionPhase + 120 49 QuartzCore 0x00000001a7c0f95c _ZN2CA11Transaction6commitEv + 336 50 AppKit 0x00000001a42e4470 __62+[CATransaction(NSCATransaction) NS_setFlushesWithDisplayLink]_block_invoke + 304 51 AppKit 0x00000001a4a3923c ___NSRunLoopObserverCreateWithHandler_block_invoke + 64 52 CoreFoundation 0x00000001a1979cc8 CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION + 36 53 CoreFoundation 0x00000001a1979b14 __CFRunLoopDoObservers + 572 54 CoreFoundation 0x00000001a197905c __CFRunLoopRun + 764 55 CoreFoundation 0x00000001a19785e8 CFRunLoopRunSpecific + 600 56 HIToolbox 0x00000001a98932a0 RunCurrentEventLoopInMode + 292 57 HIToolbox 0x00000001a9892f2c ReceiveNextEventCommon + 320 58 HIToolbox 0x00000001a9892dd4 _BlockUntilNextEventMatchingListInModeWithFilter + 72 59 AppKit 0x00000001a4167480 _DPSNextEvent + 836 60 AppKit 0x00000001a4165e20 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1292 61 AppKit 0x00000001a4157cac -[NSApplication run] + 596 62 AppKit 0x00000001a412971c NSApplicationMain + 1064 63 SwiftUI 0x00000001c20dc1b4 $s7SwiftUI6runAppys5NeverOSo21NSApplicationDelegate_pFTf4e_nAA07TestingdG0C_Tg5 + 96 64 SwiftUI 0x00000001c291fba0 $s7SwiftUI6runAppys5NeverOxAA0D0RzlF + 220 65 SwiftUI 0x00000001c24c9854 $s7SwiftUI3AppPAAE4mainyyFZ + 128 66 UniversalNavigationMacOS 0x000000010423c784 $s24UniversalNavigationMacOS0abC5OSAppV5$mainyyFZ + 60 67 UniversalNavigationMacOS 0x000000010423c824 main + 12 68 libdyld.dylib 0x00000001a1899450 start + 4 )

[NilsBerni]

@lbrndnr I'm using a M1 MacBook. However, I'm confident the issue is also occurring on other devices. I've tried to reproduce the same bug without your custom StackNavigationVIew without success. Therefore, I'm sure that this issue is related to your lib but I couldn't resolve it, maybe you have an idea.