AppEngine Multiple User Credentials in Development

Question

When auth-constraint is specified in AppEngine Development server web.xml file. The User injected to endpoint and User received from UserService.getCurrentUser() in HttpServlet are different.

The user Id for endpoint user is zero and for HttpServlet it is a fixed number. When the auth-constraint tag is removed from web.xml file, both user ids are zero. But this tag is required for production server.

How to get a single user for development server?

<security-constraint>
    <web-resource-collection>
        <web-resource-name>all</web-resource-name>
        <url-pattern>/*</url-pattern>
    </web-resource-collection>
    <auth-constraint>
        <role-name>*</role-name>
    </auth-constraint>
    <user-data-constraint>
        <transport-guarantee>CONFIDENTIAL</transport-guarantee>
    </user-data-constraint>
</security-constraint>