org.infinispan.lucene.InfinispanDirectoryIOTest.testReadWholeFile fails randomly

java.lang.NullPointerException
	at org.infinispan.lucene.DirectoryIntegrityCheck.verifyDirectoryStructure(DirectoryIntegrityCheck.java:76)
	at org.infinispan.lucene.DirectoryIntegrityCheck.verifyDirectoryStructure(DirectoryIntegrityCheck.java:56)
	at org.infinispan.lucene.InfinispanDirectoryIOTest.verifyOnBuffer(InfinispanDirectoryIOTest.java:184)
	at org.infinispan.lucene.InfinispanDirectoryIOTest.testReadWholeFile(InfinispanDirectoryIOTest.java:153)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:80)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:715)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:907)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1237)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
	at org.testng.TestRunner.privateRun(TestRunner.java:767)
	at org.testng.TestRunner.run(TestRunner.java:617)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
	at org.testng.SuiteRunner.access$000(SuiteRunner.java:37)
	at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:368)
	at org.testng.internal.thread.ThreadUtil$2.call(ThreadUtil.java:64)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
	at java.util.concurrent.FutureTask.run(FutureTask.java:166)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:722)