External links containing the primary hostname are being converted to internal links when the link dialog is closed. As far as I can tell this was reported in CMS-4284, and may be a regression?

Additonally the code that is runing the internal link conversion is unable to handle links that don't resolve to internal pages. An error is thrown when trying to target a custom route within the same application.

The following error is returned from the XHR request that tries to update the link property. Authors simply see an empty link property. Returning to the link dialog all fields are empty.

Exception details: ArgumentException: Value cannot be null or empty. Parameter name: controllerName
Stack trace:
[ArgumentException: Value cannot be null or empty.
Parameter name: controllerName]
at System.Web.Mvc.HandleErrorInfo..ctor(Exception exception, String controllerName, String actionName)
at System.Web.Mvc.HandleErrorAttribute.OnException(ExceptionContext filterContext)
at System.Web.Mvc.ControllerActionInvoker.InvokeExceptionFilters(ControllerContext controllerContext, IList`1 filters, Exception exception)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c_DisplayClass21.b_1e(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult)
at EPiServer.Shell.Services.Rest.RestControllerBase.EndExecute(IAsyncResult asyncResult)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

If this is a feature, I'd vote that it shouldn't be.