WebView error if we leave page while it's navigating

Description

If we have a webview and it's navigating somewhere, say for example we pressed on a link and it's loading a page, if while that navigation is taking place we leave the page where the webview is, we get an error.

ObjCRuntime.ObjCException
  Message=Objective-C exception thrown.  Name: NSInternalInconsistencyException Reason: Completion handler passed to -[Microsoft_Maui_Platform_MauiWebViewUIDelegate webView:contextMenuConfigurationForElement:completionHandler:] was not called
Native stack trace:
    0   CoreFoundation                      0x00007ff80048d28d __exceptionPreprocess + 242
    1   libobjc.A.dylib                     0x00007ff800057894 objc_exception_throw + 48
    2   CoreFoundation                      0x00007ff80048d16b -[NSException initWithCoder:] + 0
    3   WebKit                              0x00000001119ba879 _ZN6WebKit28CompletionHandlerCallCheckerD2Ev + 127
    4   WebKit                              0x0000000111a223d5 _ZNK3WTF20ThreadSafeRefCountedIN6WebKit28CompletionHandlerCallCheckerELNS_17DestructionThreadE0EE5derefEv + 33
    5   WebKit                              0x00000001121a0a69 _ZZN3WTF8BlockPtrIFvP26UIContextMenuConfigurationEE12fromCallableIZ70-[WKContentView(WKInteractionPreview) continueContextMenuInteraction:]E5$_102EES4_T_ENUlPKvE_8__invokeES9_ + 31
    6   libsystem_blocks.dylib              0x00007ff8000c1214 _call_dispose_helpers_excp + 45
    7   libsystem_blocks.dylib              0x00007ff8000c1ea5 _Block_release + 232
    8   libdispatch.dylib                   0x00007ff80014bd3a _dispatch_client_callout + 8
    9   libdispatch.dylib                   0x00007ff80015aac0 _dispatch_main_queue_drain + 1420
    10  libdispatch.dylib                   0x00007ff80015a526 _dispatch_main_queue_callback_4CF + 31
    11  CoreFoundation                      0x00007ff8003e9850 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
    12  CoreFoundation                      0x00007ff8003e418b __CFRunLoopRun + 2463
    13  CoreFoundation                      0x00007ff8003e3409 CFRunLoopRunSpecific + 557
    14  GraphicsServices                    0x00007ff80a650187 GSEventRunModal + 137
    15  UIKitCore                           0x000000011b1df3a2 -[UIApplication _run] + 972
    16  UIKitCore                           0x000000011b1e3e10 UIApplicationMain + 123
    17  libxamarin-dotnet-debug.dylib       0x00000001056f850a xamarin_UIApplicationMain + 58
    18  libmonosgen-2.0.dylib               0x0000000105e960f5 do_icall + 341
    19  libmonosgen-2.0.dylib               0x0000000105e94887 do_icall_wrapper + 295
    20  libmonosgen-2.0.dylib               0x0000000105e855a6 mono_interp_exec_method + 3990
    21  libmonosgen-2.0.dylib               0x0000000105e82d13 interp_runtime_invoke + 259
    22  libmonosgen-2.0.dylib               0x0000000105f69748 mono_runtime_invoke_checked + 136
    23  libmonosgen-2.0.dylib               0x0000000105f7109b mono_runtime_exec_main_checked + 107
    24  libmonosgen-2.0.dylib               0x0000000105dd5482 mono_jit_exec + 354
    25  libxamarin-dotnet-debug.dylib       0x000000010573cbea xamarin_main + 1898
    26  WebViewCrashMidLoad                 0x0000000103dd4a04 main + 68
    27  dyld                                0x00000001047023ee start_sim + 10
    28  ???                                 0x00000001089f13a6 0x0 + 4439610278
  Source=Microsoft.iOS
  StackTrace:
   at ObjCRuntime.Runtime.ThrowNSException(IntPtr ns_exception) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/ObjCRuntime/Runtime.cs:line 507
   at ObjCRuntime.Runtime.throw_ns_exception(IntPtr exc) in /Users/builder/azdo/_work/1/s/xamarin-macios/runtime/Delegates.generated.cs:line 279
   at UIKit.UIApplication.UIApplicationMain(Int32 argc, String[] argv, IntPtr principalClassName, IntPtr delegateClassName) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/UIKit/UIApplication.cs:line 58
   at UIKit.UIApplication.Main(String[] args, Type principalClass, Type delegateClass) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/UIKit/UIApplication.cs:line 94
   at WebViewCrashMidLoad.Program.Main(String[] args) in C:\Users\ortiz\source\repos\WebViewCrashMidLoad\WebViewCrashMidLoad\Platforms\iOS\Program.cs:line 13

Steps to Reproduce

press click me to open a modal page with a web view. press on a link in the webview to make it load that url, while that's taking place leave the page by pressing click me.

Link to public reproduction project repository

https://github.com/ESO-ST/WebViewCrashMidLoad

Version with bug

8.0.7 SR2

Is this a regression from previous behavior?

Yes, this used to work in Xamarin.Forms

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

iOS 15

Did you find any workaround?

No response

Relevant log output

No response

After using the nightly version of MAUI that has this fix, we now get this error

14:23:47:238    Unhandled Exception:
14:23:47:238    System.InvalidOperationException: VirtualView cannot be null here
14:23:47:238       at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.IWebView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[WebKit.WKWebView, Microsoft.iOS, Version=17.2.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065]].get_VirtualView()
14:23:47:238       at Microsoft.Maui.Handlers.WebViewHandler.Microsoft.Maui.Handlers.IWebViewHandler.get_VirtualView()
14:23:47:238       at Microsoft.Maui.Platform.MauiWebViewNavigationDelegate.DecidePolicy(WKWebView webView, WKNavigationAction navigationAction, Action`1 decisionHandler)
14:23:47:238       at UIKit.UIApplication.UIApplicationMain(Int32 argc, String[] argv, IntPtr principalClassName, IntPtr delegateClassName) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/UIKit/UIApplication.cs:line 58
14:23:47:238       at UIKit.UIApplication.Main(String[] args, Type principalClass, Type delegateClass) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/UIKi
14:23:47:238    t/UIApplication.cs:line 94
14:23:47:238       at WebViewCrashMidLoad.Program.Main(String[] args) in C:\Users\Salem\source\repos\WebViewCrashMidLoad\WebViewCrashMidLoad\Platforms\iOS\Program.cs:line 13
14:23:47:238    2024-04-05 19:23:47.148522+0100 WebViewCrashMidLoad[39290:225312] Unhandled managed exception: VirtualView cannot be null here (System.InvalidOperationException)
14:23:47:238       at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.IWebView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[WebKit.WKWebView, Microsoft.iOS, Version=17.2.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065]].get_VirtualView()
14:23:47:238       at Microsoft.Maui.Handlers.WebViewHandler.Microsoft.Maui.Handlers.IWebViewHandler.get_VirtualView()
14:23:47:238       at Microsoft.Maui.Platform.MauiWebViewNavigationDelegate.DecidePolicy(WKWebView webView, WKNavigationAction navigationAction, Action`1 decisionHandler)
14:23:47:238       at UIKit.UIApplication.UIApplicationMain(Int32 argc, String[] argv, IntPtr principalClassName, IntPtr delegateClassName) in /Users/builder/azdo/_work/1/s/xamarin-macios/src/UIKit/UIApplication.cs:line 58
14:23:47:238       at UIKit.UIApplication.Main(String[] args, Type principalClass, Type delegateClass) in /Users/builder/azdo/_work/1/s/xamarin-macios/
14:23:47:238    src/UIKit/UIApplication.cs:line 94
14:23:47:238       at WebViewCrashMidLoad.Program.Main(String[] args) in C:\Users\Salem\source\repos\WebViewCrashMidLoad\WebViewCrashMidLoad\Platforms\iOS\Program.cs:line 13

I do want to note that our WebView is inside a Mopups Popup page, the repro project was also updated to reflect that and the issue is reproduceable there as well.

dotnet / maui