PolicyFile not bijective for some characters

package net.java.spnego;

import static org.junit.Assert.*;

import java.io.StringReader;
import java.io.StringWriter;

import org.junit.Test;

import sun.security.provider.PolicyParser;
import sun.security.provider.PolicyParser.PrincipalEntry;

/**
 * This is a demo of the current bug in the PolicyParser/StreamTokenizer of the JDK.
 * @author BJB
 */
public class PolicyFileTest {

    /**
     * This test will work
     */
    @Test
    public void simpleTest() {
        test("ROLE");
    }

    /**
     * This test will work
     */
    @Test
    public void backslashTest() {
        test("ROLE_\00\01");
    }

    /**
     * This test will fail as in the current PolicyFile reader
     * neither the writer generates the correct value (double backslash) nor the parser
     * handle the double backslash case
     */
    @Test
    public void doubleBackslashTest() {
        test("ROLE_\\00\\01");
    }


    @SuppressWarnings("restriction")
    void test(String name) {
        try{

        final String theClass = "foo.test.PrincipalClass";
        final String theGroup = name;

        final StringWriter s = new StringWriter();

        PolicyParser pp = new PolicyParser(true);
        PolicyParser.GrantEntry ge = new PolicyParser.GrantEntry(name, name);
        ge.principals.add(new PolicyParser.PrincipalEntry("foo.test.PrincipalClass",theGroup));
        pp.add(ge);
        pp.write(s);

        String policy = s.toString();
        StringReader r = new StringReader(policy);

        PolicyParser p2 = new PolicyParser(true);
        p2.read(r);

        PolicyParser.GrantEntry g2 = p2.grantElements().nextElement();
        PrincipalEntry principal = g2.principals.element();

        assertEquals(theClass, principal.getPrincipalClass());
        assertEquals(theGroup, principal.getPrincipalName());

        }catch(Exception e){
            fail("Failing test with "+name+"(len="+name.length()+") because: "+e.getLocalizedMessage());
        }

    }

}