Menu item can only be found after getting GetMainWindow again

[aristotelos]

Describe the bug
I have some code that finds a menu item from the current main window. I have observed the following:

• When I remember the Window returned by GetMainWindow and call FindFirstDescendant on it, it returns null
• When I call GetMainWindow again after the menu has been clicked and call FindFirstDescendant on that new Window instance returned, it returns the menu item

The element tree was as following:

Window > Menu Bar > Menu Item (clicked) > Menu > Menu Item (to be found and clicked)

Code snippets
This was discovered while working on a FlaUI WebDriver implementation. Here is the part that refreshes the Window all the time to work around this issue:

FlaUI/src/FlaUI.WebDriver/Session.cs

Lines 49 to 54 in b1f61c1

	if (CurrentWindowWithHandle.Window.IsMainWindow)
	{
	// When expanding menus, calling `GetMainWindow` again is necessary to be able to find the expanded menu items
	// This seems to be a bug (it isn't solved by using `CacheRequest.ForceNoCache()`)
	return App.GetMainWindow(Automation);
	}

Additional context
Using UIA3.

[aristotelos]

This may be a bug in the Windows UIA3 implementation itself, so that it is impossible to fix in FlaUI. I found the same issue exists in WinAppDriver and the workaround is to re-retrieve the menu item after it has been clicked:

        await TestFixture.cam2DDriver.$(`[name="View"]`).click();
        // WinAppDriver doesn't find $(`[name="Toolbars"]`) straight away
        await TestFixture.cam2DDriver.$(`[name="View"]`).$(`[name="Toolbars"]`).click();
        // WinAppDriver doesn't find $(`[name="${toolbar_name}"]`) straight away
        await TestFixture.cam2DDriver.$(`[name="View"]`).$(`[name="Toolbars"]`).$(`[name="${toolbar_name}"]`).click(); 

[maxinfet]

I have experienced this issue using raw UIAv2 and UIAv3 outside of FlaUI, unfortunately. My guess is that this has something to do with claiming ownership of the windows that menus create but either way it can't be fixed in FlaUI directly.