sun/net/www/protocol/jar/B4957695.java fails intermittently with java.lang.RuntimeException: some jar_cache files left behind

This is an intermittent failure. It looks probably a regression issue.

Please see the test output:
----------System.out:(2/68)----------
Server: listening on port: 44791
Received IOException as expected
----------System.err:(12/645)----------
java.lang.RuntimeException: some jar_cache files left behind
at B4957695.main(B4957695.java:114)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:520)
at com.sun.javatest.regtest.agent.MainActionHelper$SameVMRunnable.run(MainActionHelper.java:218)
at java.lang.Thread.run(Thread.java:806)