org.jboss.test.cluster.defaultcfg.web.test.CleanShutdownTestCase checks the behaviour of HTTP requests to a server which in the process of shutting down.
As part of its processing, it uses a method

Cookie findCookie(int serverIndex, String name)

to find a cookie with a given name on a given server (usually indexed by 0 or 1).
Cookies are matched when they have the same domain and name.

Cookie domains can be represented as hostnames, or IP address literals.

Our version of HttpClient (which I hacked about one year ago) will always use enclosing brackets when presented with an IPv6 address literal.
HttpClient 3.0.1 and 3.1 did not support IPv6 address literals at the time.

I may have to reinvestigate what the correct standard is, but for the time being, the above test is failing because findCookie does not wrap IPv6 address literals
in square brackets before trying to match. As a result, we get assertion failures in the test, even though we have the correct cookies being returned:

Error Message
null

Stacktrace
junit.framework.AssertionFailedError: null
at org.jboss.test.cluster.defaultcfg.web.test.CleanShutdownTestCase.testShutdown(CleanShutdownTestCase.java:164)
at junit.extensions.TestDecorator.basicRun(TestDecorator.java:24)
at junit.extensions.TestSetup$1.protect(TestSetup.java:23)
at junit.extensions.TestSetup.run(TestSetup.java:27)

Standard Output
After initial request
[fec0:0:a16:ffff::d] JSESSIONID /http-sr Eiq93h0lJFU7W6Y7YDNnXw__.cluster-udp-DIST-0
After request initiated prior to shutdown
[fec0:0:a16:ffff::d] JSESSIONID /http-sr Eiq93h0lJFU7W6Y7YDNnXw__.cluster-udp-DIST-0
[fec0:0:a16:ffff::d] sleep /http-sr 0

findCookie(0, "0") is trying to match on the pair ("fec0:0:a16:ffff::d", "0")