Crash Caused by Re-Entrancy Due to Call to m_coreWebViewController.IsVisible(...)

[brianrob]

Describe the bug

When using WebView2 from XAML, there is an intermittent crash due to re-entrancy. This results when calling CoreWebView2Controller::IsVisible, which calls ShowWindow, which pumps messages.

Steps to reproduce the bug

I don't have a minimal repro, but can share the relevant part of the stack:

ntdll!KiUserCallbackDispatcherContinue

win32u!ZwUserShowWindow+0x14

EmbeddedBrowserWebView!embedded_browser_webview_current::Controller::SyncVisibility+0x64

EmbeddedBrowserWebView!embedded_browser_webview_current::Controller::put_IsVisible+0xb7

Microsoft_Web_WebView2_Core!winrt::Microsoft::Web::WebView2::Core::implementation::CoreWebView2Controller::IsVisible+0x57

Microsoft_Web_WebView2_Core!winrt::impl::produce<winrt::Microsoft::Web::WebView2::Core::implementation::CoreWebView2Controller,winrt::Microsoft::Web::WebView2::Core::ICoreWebView2Controller>::put_IsVisible+0x60

Microsoft_UI_Xaml_Controls!winrt::impl::consume_Microsoft_UI_Xaml_IUIElementOverrides<winrt::Microsoft::UI::Xaml::IUIElementOverrides>::OnDisconnectVisualChildren+0x14

Microsoft_UI_Xaml_Controls!WebView2::UpdateCoreWebViewVisibility::__l10::<lambda_2>::operator()+0x12

Microsoft_UI_Xaml_Controls!WebView2::CoreWebView2RunIgnoreInvalidStateSync<`WebView2::UpdateCoreWebViewVisibility'::`10'::<lambda_2> >+0x16

Microsoft_UI_Xaml_Controls!WebView2::UpdateCoreWebViewVisibility+0xed

Per @codendone, the fix here is to add a PauseNewDispatch around the call to m_coreWebViewController.IsVisible(...).

Expected behavior

The application should not crash.

Screenshots

No response

NuGet package version

None

Windows version

Windows 11 (23H2): Build 22631

Additional context

No response