WTFCrashWithInfo (WebKit) iOS 17.4

Question

Created Feb ’24

Replies 2

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Participants 1

Hello there, we have an iOS application which has been out for quite some time with a custom WKWebView which has been throwing the following exception on the latest iOS 17.4 (Beta)

The application appears to freeze / crash when interacting with input on a WKWebView. Our application also uses react-native, but up until this particular iOS version everything has been working smoothly (since about iOS 12.0 or so).

Here is some more details on the environment

iPhone 15 Pro (can reproduce on simulator as well)
iOS 17.4 (Beta)
Physical device

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BREAKPOINT (code=1, subcode=0x1a195a918)
  * frame #0: 0x00000001a195a918 WebKit`WTFCrashWithInfo(int, char const*, char const*, int) + 20
    frame #1: 0x00000001a25ef8fc WebKit`-[WKContentView(WKInteraction) textInputTraits] + 288
    frame #2: 0x00000001c77689c8 PencilKit`+[PKTextInputUtilities textInputTraitsFromTextInput:] + 112
    frame #3: 0x00000001c7768be8 PencilKit`+[PKTextInputUtilities isResponderSupportedTextInput:checkForNotes:outTextInputTraits:] + 64
    frame #4: 0x00000001c77d5128 PencilKit`+[PKTextInputElementsFinder isResponderEditableTextInput:] + 56
    frame #5: 0x00000001c78f29a0 PencilKit`-[PKTextInputWindowFirstResponderController _updateFirstResponder:isVisible:sendDelegateCallback:] + 224
    frame #6: 0x00000001c78f2dd8 PencilKit`-[PKTextInputWindowFirstResponderController _textInputResponderDidChangeNotificationHandler:] + 244
    frame #7: 0x000000018c7b67a8 CoreFoundation`__CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148
    frame #8: 0x000000018c7b6170 CoreFoundation`___CFXRegistrationPost_block_invoke + 88
    frame #9: 0x000000018c7b60b8 CoreFoundation`_CFXRegistrationPost + 440
    frame #10: 0x000000018c7b5608 CoreFoundation`_CFXNotificationPost + 728
    frame #11: 0x000000018b65ee10 Foundation`-[NSNotificationCenter postNotificationName:object:userInfo:] + 92
    frame #12: 0x000000018f63b02c UIKitCore`-[UIKeyboardImpl _postInputResponderChangedNotification] + 224
    frame #13: 0x000000018f63c74c UIKitCore`-[UIKeyboardImpl _setDelegate:existingDelegate:force:delayEndInputSession:] + 480
    frame #14: 0x000000018ebd4368 UIKitCore`-[UIKeyboardImpl setDelegate:force:delayEndInputSession:] + 664
    frame #15: 0x000000018eb931a8 UIKitCore`-[UIKeyboardSceneDelegate _reloadInputViewsForKeyWindowSceneResponder:force:fromBecomeFirstResponder:] + 2916
    frame #16: 0x000000018eb92604 UIKitCore`-[UIKeyboardSceneDelegate _reloadInputViewsForResponder:force:fromBecomeFirstResponder:] + 88
    frame #17: 0x000000018f860ee4 UIKitCore`-[UIResponder(UIResponderInputViewAdditions) reloadInputViews] + 84
    frame #18: 0x00000001a25f3cb4 WebKit`-[WKContentView(WKInteraction) _elementDidFocus:userIsInteracting:blurPreviousNode:activityStateChanges:userObject:] + 1800
    frame #19: 0x00000001a1f58024 WebKit`WebKit::PageClientImpl::elementDidFocus(WebKit::FocusedElementInformation const&, bool, bool, ***::OptionSet<WebCore::ActivityState>, API::Object*) + 108
    frame #20: 0x00000001a1f8713c WebKit`WebKit::WebPageProxy::elementDidFocus(WebKit::FocusedElementInformation const&, bool, bool, ***::OptionSet<WebCore::ActivityState>, WebKit::UserData const&) + 168
    frame #21: 0x00000001a252b9d0 WebKit`WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 24380
    frame #22: 0x00000001a263f628 WebKit`IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) + 264
    frame #23: 0x00000001a20e9be0 WebKit`WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 44
    frame #24: 0x00000001a263a690 WebKit`IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder>>) + 324
    frame #25: 0x00000001a263abb0 WebKit`IPC::Connection::dispatchIncomingMessages() + 708
    frame #26: 0x00000001a2887524 JavaScriptCore`***::RunLoop::performWork() + 204
    frame #27: 0x00000001a288844c JavaScriptCore`***::RunLoop::performWork(void*) + 36
    frame #28: 0x000000018c7be62c CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
    frame #29: 0x000000018c7bd8a8 CoreFoundation`__CFRunLoopDoSource0 + 176
    frame #30: 0x000000018c7bc0b8 CoreFoundation`__CFRunLoopDoSources0 + 340
    frame #31: 0x000000018c7bad88 CoreFoundation`__CFRunLoopRun + 828
    frame #32: 0x000000018c7ba968 CoreFoundation`CFRunLoopRunSpecific + 608
    frame #33: 0x00000001d0ecf4e0 GraphicsServices`GSEventRunModal + 164
    frame #34: 0x000000018ec37350 UIKitCore`-[UIApplication _run] + 888
    frame #35: 0x000000018ec3698c UIKitCore`UIApplicationMain + 340
    frame #36: 0x0000000100499dec Padlet`main(argc=1, argv=0x000000016f96f708) at main.m:8:14
    frame #37: 0x00000001b00fed84 dyld`start + 2240

Stack traces generated with bt command.

The crash mentions PencilKit but afaik we aren't supporting that here. Any help would be greatly appreciated, many thanks!

Answered by Asleepace in 780775022

The sharedToolPickerForWindow: method is now deprecated, the solution was to change the code to the following:

- (void)setToolPicker API_AVAILABLE(ios(13)) {
  self.picker = [[PKToolPicker alloc] init];
  [self.picker addObserver:self.canvas];
  [self.picker setVisible:true forFirstResponder:self.canvas];
  [self.canvas becomeFirstResponder];
}

This was quite difficult to find since it was hidden in an npm package we were using.

Boost

Answer 1

Asleepace OP

Feb ’24

The issue was seemingly unrelated, we had the following code elsewhere in our code-base which allows for drawing with the Apple Pencil.

- (void)setToolPicker API_AVAILABLE(ios(13)) {
  UIWindow *window = [[[UIApplication sharedApplication] delegate] window];
  self.picker = [PKToolPicker sharedToolPickerForWindow:window];
  [self.picker addObserver:self.canvas];
  [self.picker setVisible:true forFirstResponder:self.canvas];
  [self.canvas becomeFirstResponder];
}

Since our application is a react-native application, the native modules are instantiated as singletons when the app launches

[[[UIApplication sharedApplication] delegate] window];

So this but of code appears to set a PKToolPicker tool bar for everything (including text input on our webviews).

0

Answer 2

Asleepace OP

Feb ’24

Accepted Answer

The sharedToolPickerForWindow: method is now deprecated, the solution was to change the code to the following:

- (void)setToolPicker API_AVAILABLE(ios(13)) {
  self.picker = [[PKToolPicker alloc] init];
  [self.picker addObserver:self.canvas];
  [self.picker setVisible:true forFirstResponder:self.canvas];
  [self.canvas becomeFirstResponder];
}

This was quite difficult to find since it was hidden in an npm package we were using.

0