Edited Unassigned: v15.1.x ValidatorCallout static images - incorrect path with ScriptManager.EnableCdn= false [27875]

I have found that unless the ScriptManager has EnableCdn set to true, the images used in the display of the ValidatorCallout (warning and close icons) have an incorrect path set, so both images return a 404.

While the Nuget package installs the images here in my application:
~/Content/AjaxControlToolkit/Images/ValidatorCallout.Close.gif
~/Content/AjaxControlToolkit/Images/ValidatorCallout.Alert-Large.gif

If I set the ScriptManager.EnableCdn to false, the paths actually generated are:
~/[AspxPageContentServedFromFolder]/Content/AjaxControlToolkit/Images/ValidatorCallout.Close.gif
~/[AspxPageContentServedFromFolder]/Content/AjaxControlToolkit/Images/ValidatorCallout.Alert-Large.gif

The [AspxPageContentServedFromFolder] is the folder where the ASPX page resides on disk, but in my case the URL is different, because the URL has been mapped to this ASPX page with the RouteTable.Routes.MapPageRoute() method on app startup.

Shouldn't the image URL always be absolute from the app root if being served locally?