App crashes when using a swiftUI textfield and a WKWebView textfield

Question

I currently have an app which uses a SwiftUI textfield above a Website's text field (let's say a search box). The app doesn't crash in iOS or iPadOS.

However, in MacCatalyst on an M1 mac, the app instantly crashes when I click the SwiftUI text field then click the search bar on the website.

I created a reproducible example that's attached below (ran in XCode 13.2.1)

To reproduce the crash:

1. Launch the app on a mac (preferably M1)
2. Click in the textfield
3. Click on the google search bar
4. The crash should occur

The crash also occurs in the logs when running on Rosetta, but the app doesn't terminate.

Does anyone know what the problem is and how I can fix this? Thank you in advance.

import SwiftUI
import WebKit

struct ContentView: View {
  @State var textObject: String = ""
   
  var body: some View {
    ZStack {
      WebView(url: URL(string: "https://google.com")!)

      TextField("", text: $textObject)
        .background(
          Rectangle()
            .foregroundColor(.black)
        )
    }
  }
}

struct WebView: UIViewRepresentable {   
  var url: URL
 
  func makeUIView(context: Context) -> WKWebView {
    return WKWebView()
  }
 
  func updateUIView(_ webView: WKWebView, context: Context) {
    let request = URLRequest(url: url)
    webView.load(request)
  }
}

Here's the error message from XCode: libc++abi: terminating with uncaught exception of type NSException *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid parameter not satisfying: <SPRoundedWindow: 0x126774250>. "frame=!CGRectIsNull(frame)"' terminating with uncaught exception of type NSException libc++abi: terminating with uncaught exception of type NSException *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid parameter not satisfying: <SPRoundedWindow: 0x126774250>. "frame=!CGRectIsNull(frame)"' terminating with uncaught exception of type NSException

My crash trace:

0   CoreFoundation                      0x00000001848001cc __exceptionPreprocess + 240
1   libobjc.A.dylib                     0x00000001845517b8 objc_exception_throw + 60
2   Foundation                          0x000000018576e840 -[NSMutableDictionary(NSMutableDictionary) initWithContentsOfFile:] + 0
3   AppKit                              0x0000000187328f20 -[NSWindow _reallySetFrame:] + 904
4   AppKit                              0x00000001873287d8 -[NSWindow _oldPlaceWindow:fromServer:] + 228
5   AppKit                              0x00000001873277f8 -[NSWindow _setFrameCommon:display:fromServer:] + 2200
6   SafariPlatformSupport               0x00000001aac63104 __85-[SPSafariPlatformSupport displayOTPAutoFillRelativeToRect:ofView:completionHandler:]_block_invoke + 300
7   SafariPlatformSupport               0x00000001aac62f8c -[SPSafariPlatformSupport displayOTPAutoFillRelativeToRect:ofView:completionHandler:] + 228
8   UIKitCore                           0x00000001ac7317a0 -[UIKeyboardImpl generateAutofillCandidateByAddingTask:] + 948
9   UIKitCore                           0x00000001ac73b8d0 -[UIKeyboardImpl setDelegate:force:] + 6248
10  UIKitCore                           0x00000001ac41fad4 -[UIKeyboardSceneDelegate _reloadInputViewsForKeyWindowSceneResponder:] + 2080
11  UIKitCore                           0x00000001ac41f288 -[UIKeyboardSceneDelegate _reloadInputViewsForResponder:] + 164
12  UIKitCore                           0x00000001abd918a0 -[UIResponder(UIResponderInputViewAdditions) reloadInputViews] + 132
13  UIKitCore                           0x00000001abd3a298 -[UIResponder becomeFirstResponder] + 856
14  UIKit                               0x0000000202830aa4 -[UITextInputUIResponderAccessibility becomeFirstResponder] + 52
15  UIKitCore                           0x00000001abd6a100 -[UIView(Hierarchy) becomeFirstResponder] + 176
16  WebKit                              0x00000001bd66c5c0 -[WKContentView(WKInteraction) becomeFirstResponderForWebView] + 152
17  WebKit                              0x00000001bd246768 -[WKWebView(WKViewInternalIOS) becomeFirstResponder] + 148
18  WebKit                              0x00000001bd67f88c -[WKContentView(WKInteraction) _elementDidFocus:userIsInteracting:blurPreviousNode:activityStateChanges:userObject:] + 1840
19  WebKit                              0x00000001bd381ea0 _ZN6WebKit12WebPageProxy15elementDidFocusERKNS_25FocusedElementInformationEbbN3***9OptionSetIN7WebCore13ActivityState4FlagEEERKNS_8UserDataE + 216
20  WebKit                              0x00000001bd5f66b8 _ZN6WebKit12WebPageProxy17didReceiveMessageERN3IPC10ConnectionERNS1_7DecoderE + 61472
21  WebKit                              0x00000001bcfcc5cc _ZN3IPC18MessageReceiverMap15dispatchMessageERNS_10ConnectionERNS_7DecoderE + 272
22  WebKit                              0x00000001bd35a284 _ZN6WebKit15WebProcessProxy17didReceiveMessageERN3IPC10ConnectionERNS1_7DecoderE + 40
23  WebKit                              0x00000001bcfaeb4c _ZN3IPC10Connection15dispatchMessageENSt3__110unique_ptrINS_7DecoderENS1_14default_deleteIS3_EEEE + 808
24  WebKit                              0x00000001bcfae15c _ZN3IPC10Connection24dispatchIncomingMessagesEv + 508
25  JavaScriptCore                      0x00000001bc5278d0 _ZN3***7RunLoop11performWorkEv + 292
26  JavaScriptCore                      0x00000001bc528a40 _ZN3***7RunLoop11performWorkEPv + 36
27  CoreFoundation                      0x0000000184780c5c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
28  CoreFoundation                      0x0000000184780ba8 __CFRunLoopDoSource0 + 208
29  CoreFoundation                      0x0000000184780894 __CFRunLoopDoSources0 + 268
30  CoreFoundation                      0x000000018477f208 __CFRunLoopRun + 820
31  CoreFoundation                      0x000000018477e734 CFRunLoopRunSpecific + 600
32  HIToolbox                           0x000000018d310f68 RunCurrentEventLoopInMode + 292
33  HIToolbox                           0x000000018d310cdc ReceiveNextEventCommon + 552
34  HIToolbox                           0x000000018d310a9c _BlockUntilNextEventMatchingListInModeWithFilter + 72
35  AppKit                              0x00000001872d4ce0 _DPSNextEvent + 844
36  AppKit                              0x00000001872d3584 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1332
37  AppKit                              0x00000001872c55a4 -[NSApplication run] + 596
38  AppKit                              0x0000000187296c78 NSApplicationMain + 1064
39  AppKit                              0x000000018756d084 +[NSWindow _savedFrameFromString:] + 0
40  UIKitMacHelper                      0x0000000199c7d9ac UINSApplicationMain + 1280
41  UIKitCore                           0x00000001abc0ab28 UIApplicationMain + 164
42  SwiftUI                             0x00000001c0fce8b0 $s7SwiftUI17KitRendererCommon33_ACC2C5639A7D76F611E170E831FCA491LLys5NeverOyXlXpFAESpySpys4Int8VGSgGXEfU_ + 164
43  SwiftUI                             0x00000001c0fce808 $s7SwiftUI6runAppys5NeverOxAA0D0RzlF + 252
44  SwiftUI                             0x00000001c08f54cc $s7SwiftUI3AppPAAE4mainyyFZ + 128
45  TestingGround                       0x000000010056d634 $s13TestingGround0aB3AppV5$mainyyFZ + 40
46  TestingGround                       0x000000010056d6d4 main + 12
47  dyld                                0x00000001015a50f4 start + 520

Answer 1

I'm not sure what is the offender here, probably MacCatalyst itself, but the answer is literally disabling autocorrect on the textfield.

The reason is because running MacCatalyst apps assume that there's a virtual keyboard with a TextField, so errors like these appear often in production code. For some reason, this causes a crash on M1 devices. Disabling predictive text is the solution to this problem. Here's the code:

import SwiftUI
import WebKit

struct ContentView: View {
  @State var textObject: String = ""
   
  var body: some View {
    ZStack {
      WebView(url: URL(string: "https://google.com")!)

      TextField("", text: $textObject)
        .background(
          Rectangle()
            .foregroundColor(.black)
        )
        .disableAutoCorrection(true)
    }
  }
}

struct WebView: UIViewRepresentable {   
  var url: URL
 
  func makeUIView(context: Context) -> WKWebView {
    return WKWebView()
  }
 
  func updateUIView(_ webView: WKWebView, context: Context) {
    let request = URLRequest(url: url)
    webView.load(request)
  }
}

Answer 2

I worked around this crash by swizzling the private method -[NSWindow _reallySetFrame:] and manually correct the faulty input. I haven't found any side effect of this swizzle so far.

@objc private extension NSWindow {
    
    func kjy_swizzle_reallySetFrame(_ frame: CGRect) {
        var frame = frame
        if frame.isNull {
            frame = .zero
        }
        kjy_swizzle_reallySetFrame(frame)
    }
}

Note: this is not the complete source code for the workaround to work (you need to add code to swizzle the private NSWindow method). If you are not familiar with "method swizzling" please search it on the internet.

Answer 3

I also faced the same crash in swift with the WKWebView of maccatalyst. After trying different solution finally I added this code to fix my crash.

    typealias winClosureType =  @convention(c) (Any, Selector) -> UITextAutocorrectionType
func swizzleInputTraits() {
    guard let textInputTraits: AnyClass = NSClassFromString("UITextInputTraits") else { return }
    let sel_AutocorrectionType: Selector = sel_getUid("autocorrectionType")
    
    if let method = class_getInstanceMethod(textInputTraits, sel_AutocorrectionType) {
        let originalImp: IMP = method_getImplementation(method)
        let original: winClosureType = unsafeBitCast(originalImp, to: winClosureType.self)

        let block : @convention(block) (Any) -> UITextAutocorrectionType = { (textInputTraits) in
            let obj = original(textInputTraits, sel_AutocorrectionType)
            
            return obj == .default ? .no : obj
        }
        let imp: IMP = imp_implementationWithBlock(block)
        method_setImplementation(method, imp)
    }
}

Here i am swizzling the autocorrectionType property of UITextInputTraits. I am disabling the autocorrectionType by default for all the textFields. We have to explicitly enabled autocorrectionType property if needed for any text field.