MVC Global error handling

Global.asax.cs

    protected void Application_Error(Object sender, EventArgs e)
    {
      var httpContext = ((MvcApplication)sender).Context;

      var currentRouteData = RouteTable.Routes.GetRouteData(new HttpContextWrapper(httpContext));
      var currentController = " ";
      var currentAction = " ";

      if (currentRouteData != null)
      {
        if (currentRouteData.Values["controller"] != null && !String.IsNullOrEmpty(currentRouteData.Values["controller"].ToString()))
        {
          currentController = currentRouteData.Values["controller"].ToString();
        }

        if (currentRouteData.Values["action"] != null && !String.IsNullOrEmpty(currentRouteData.Values["action"].ToString()))
        {
          currentAction = currentRouteData.Values["action"].ToString();
        }
      }

      Exception ex = Server.GetLastError();

      var controller = new ErrorController();
      var routeData = new RouteData();
      var action = "InternalError";

      if (ex is HttpException)
      {
        var httpEx = ex as HttpException;

        switch (httpEx.GetHttpCode())
        {
          case (int)HttpStatusCode.NotFound:
            action = "NotFound";
            break;

          default:
            _log.ErrorIfIsEnabled(string.Format("While executing action <{0}> on controller <{1}> an exception was thrown.", currentAction, currentController), ex);

            action = "InternalError";
            break;
        }
      }
      else if (ex is FaultException<WcfValidationFault>)
      {
        var validationFault = ex as FaultException<WcfValidationFault>;
        _log.ErrorIfIsEnabled(() => "Validation fault : \r\n  " + validationFault.Detail.DumpValidationErrors("\r\n  "));

        action = "ValidationFault";
      }
      else
      {
        _log.ErrorIfIsEnabled("Exception occured : ", ex);
      }

      httpContext.ClearError();
      httpContext.Response.Clear();
      httpContext.Response.StatusCode = ex is HttpException ? ((HttpException)ex).GetHttpCode() : (int)HttpStatusCode.InternalServerError;
      httpContext.Response.TrySkipIisCustomErrors = true;
      routeData.Values["controller"] = "Error";
      routeData.Values["action"] = action;

      controller.ViewData.Model = new HandleErrorInfo(ex, currentController, currentAction);
      ((IController)controller).Execute(new RequestContext(new HttpContextWrapper(httpContext), routeData));
    }