How to check access right in SitecoreController for Sitecore 9.1

Question

In my JSON controller I want to check the access right from the User.

My code looks like this

public class MyController : SitecoreController
{

    public static bool CheckAccessRight()
    {
        if (Sitecore.Context.User.IsInRole("sitecore\\Sitecore Client Users"))
        {
            return true;
        }
        if (Sitecore.Context.User.IsAdministrator)
        {
            return true;
        }
        return false;
    }

    [System.Web.Http.HttpGet, System.Web.Http.HttpPost]
    public ActionResult DoSomethings(int page)
    {
      if (!CheckAccessRight())
      {
        return new JsonResult { Data = "access denied", JsonRequestBehavior = JsonRequestBehavior.AllowGet };
      }
      return new JsonResult { Data = "my data", JsonRequestBehavior = JsonRequestBehavior.AllowGet };
    }
}

The controller is registered in the initialize Pipeline. simiar to the documentation https://doc.sitecore.com/developers/91/sitecore-experience-management/en/use-mvc-routing.html. Works on older versions of Sitecore but in Sitecore 9.1 update-1 the Sitecore.Context.User gives not the logged in user but gives extranet\Anonymous

How can I get the actual user back?

Note: it fails in Sitecore 9.1 initial version and Sitecore 9.1 update-1. works on 9.0

Answer 1

Add ?sc_site=shell to the url, in the shell context the Sitecore user will be correct.

See also IsAdministrator check no longer working on Sitecore 9.1