org.jboss.test.jacc.test.external.AuthzDelegationUnitTestCase(jacc-security-external) failing with IBM JDK 1.6

The testcase fails with the following error:

java.io.IOException: Expected reply code:200, actual=403
at org.jboss.test.util.web.HttpUtils.accessURL(HttpUtils.java:137)
at org.jboss.test.util.web.HttpUtils.accessURL(HttpUtils.java:108)
at org.jboss.test.util.web.HttpUtils.accessURL(HttpUtils.java:96)
at org.jboss.test.util.web.HttpUtils.accessURL(HttpUtils.java:82)
at org.jboss.test.jacc.test.external.AuthzDelegationUnitTestCase.testSuccessfulWebResourceDelegation(AuthzDelegationUnitTestCase.java:56)
at junit.extensions.TestDecorator.basicRun(TestDecorator.java:24)
at junit.extensions.TestSetup$1.protect(TestSetup.java:21)
at junit.extensions.TestSetup.run(TestSetup.java:25)

The testcase deploys jacc-delegate.war, which contains a simple index.html which isn't configured as secured. Then a request is sent for http://IP_ADDRESS:8080/jacc-delegate/index.html which returns 403 with IBM JDK 1.6 (with others it returns 200).

The http request generates this logging in server.log:

2008-09-29 07:08:33,087 DEBUG [org.jboss.test.security.test.CustomSecurityConstraintProvider] Constructed.
2008-09-29 07:08:33,088 DEBUG [org.jboss.test.security.test.CustomSecurityConstraintProvider] findSecurityConstraint method called
2008-09-29 07:08:33,088 DEBUG [org.jboss.test.security.test.CustomSecurityConstraintProvider] getSecurityConstraints is for request uri=/jacc-delegate/index.html and SecurityConstraint[]=[Lorg.apache.catalina.deploy.SecurityConstraint;@3e6a3e6a