TestAddTaxonomy.testConcurrency failure

    [junit] Testsuite: org.apache.lucene.facet.taxonomy.directory.TestAddTaxonomy
    [junit] Testcase: testConcurrency(org.apache.lucene.facet.taxonomy.directory.TestAddTaxonomy):	Caused an ERROR
    [junit] Index: 1, Size: 2
    [junit] java.lang.IndexOutOfBoundsException: Index: 1, Size: 2
    [junit] 	at java.util.ArrayList.rangeCheck(ArrayList.java:604)
    [junit] 	at java.util.ArrayList.get(ArrayList.java:382)
    [junit] 	at org.apache.lucene.facet.taxonomy.writercache.cl2o.CharBlockArray.charAt(CharBlockArray.java:148)
    [junit] 	at org.apache.lucene.facet.taxonomy.CategoryPath.equalsToSerialized(CategoryPath.java:888)
    [junit] 	at org.apache.lucene.facet.taxonomy.writercache.cl2o.CompactLabelToOrdinal.getOrdinal(CompactLabelToOrdinal.java:323)
    [junit] 	at org.apache.lucene.facet.taxonomy.writercache.cl2o.CompactLabelToOrdinal.getOrdinal(CompactLabelToOrdinal.java:163)
    [junit] 	at org.apache.lucene.facet.taxonomy.writercache.cl2o.Cl2oTaxonomyWriterCache.get(Cl2oTaxonomyWriterCache.java:49)
    [junit] 	at org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyWriter.findCategory(DirectoryTaxonomyWriter.java:386)
    [junit] 	at org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyWriter.addTaxonomy(DirectoryTaxonomyWriter.java:833)
    [junit] 	at org.apache.lucene.facet.taxonomy.directory.TestAddTaxonomy.testConcurrency(TestAddTaxonomy.java:206)
    [junit] 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    [junit] 	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    [junit] 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    [junit] 	at java.lang.reflect.Method.invoke(Method.java:601)
    [junit] 	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
    [junit] 	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    [junit] 	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
    [junit] 	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    [junit] 	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    [junit] 	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:30)
    [junit] 	at org.apache.lucene.util.LuceneTestCase$SubclassSetupTeardownRule$1.evaluate(LuceneTestCase.java:630)
    [junit] 	at org.apache.lucene.util.LuceneTestCase$InternalSetupTeardownRule$1.evaluate(LuceneTestCase.java:536)
    [junit] 	at org.apache.lucene.util.SystemPropertiesInvariantRule$1.evaluate(SystemPropertiesInvariantRule.java:67)
    [junit] 	at org.apache.lucene.util.LuceneTestCase$TestResultInterceptorRule$1.evaluate(LuceneTestCase.java:457)
    [junit] 	at org.apache.lucene.util.UncaughtExceptionsRule$1.evaluate(UncaughtExceptionsRule.java:74)
    [junit] 	at org.apache.lucene.util.LuceneTestCase$SaveThreadAndTestNameRule$1.evaluate(LuceneTestCase.java:508)
    [junit] 	at org.junit.rules.RunRules.evaluate(RunRules.java:18)
    [junit] 	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
    [junit] 	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
    [junit] 	at org.apache.lucene.util.LuceneTestCaseRunner.runChild(LuceneTestCaseRunner.java:146)
    [junit] 	at org.apache.lucene.util.LuceneTestCaseRunner.runChild(LuceneTestCaseRunner.java:50)
    [junit] 	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    [junit] 	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    [junit] 	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    [junit] 	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    [junit] 	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    [junit] 	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    [junit] 	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:30)
    [junit] 	at org.apache.lucene.util.UncaughtExceptionsRule$1.evaluate(UncaughtExceptionsRule.java:74)
    [junit] 	at org.apache.lucene.util.StoreClassNameRule$1.evaluate(StoreClassNameRule.java:36)
    [junit] 	at org.apache.lucene.util.SystemPropertiesInvariantRule$1.evaluate(SystemPropertiesInvariantRule.java:67)
    [junit] 	at org.junit.rules.RunRules.evaluate(RunRules.java:18)
    [junit] 	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    [junit] 	at junit.framework.JUnit4TestAdapter.run(JUnit4TestAdapter.java:39)
    [junit] 	at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.run(JUnitTestRunner.java:518)
    [junit] 	at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.launch(JUnitTestRunner.java:1052)
    [junit] 	at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.main(JUnitTestRunner.java:879)
    [junit] 
    [junit] 
    [junit] Tests run: 5, Failures: 0, Errors: 1, Time elapsed: 0.342 sec
    [junit] 
    [junit] ------------- Standard Error -----------------
    [junit] NOTE: Ignoring nightly-only test method 'testBig'
    [junit] WARNING: test method: 'testConcurrency' left thread running: Thread[Thread-1,5,main]
    [junit] RESOURCE LEAK: test method: 'testConcurrency' left 1 thread(s) running
    [junit] NOTE: reproduce with: ant test -Dtestcase=TestAddTaxonomy -Dtestmethod=testConcurrency -Dtests.seed=ad99a0aac3d5bf3:4af538a36d0c94b4:-7b609955992bc1c9 -Dargs="-Dfile.encoding=UTF-8"
    [junit] NOTE: reproduce with: ant test -Dtestcase=TestAddTaxonomy -Dtestmethod=testConcurrency -Dtests.seed=ad99a0aac3d5bf3:4af538a36d0c94b4:-7b609955992bc1c9 -Dargs="-Dfile.encoding=UTF-8"
    [junit] NOTE: test params are: locale=mt_MT, timezone=Etc/GMT+6
    [junit] NOTE: all tests run in this JVM:
    [junit] [TwoEnhancementsTest, TestAdaptiveExample, CategoryListPayloadStreamTest, CategoryAttributeImplTest, PerDimensionIndexingParamsTest, AdaptiveAccumulatorTest, TestFacetArrays, TestFacetsAccumulatorWithComplement, FacetSearchParamsTest, SamplingAccumulatorTest, TestTaxonomyCombined, TestAddTaxonomy]
    [junit] NOTE: Linux 3.2.0-24-generic amd64/Oracle Corporation 1.7.0_01 (64-bit)/cpus=8,threads=1,free=171017984,total=269352960
    [junit] ------------- ---------------- ---------------
    [junit] TEST org.apache.lucene.facet.taxonomy.directory.TestAddTaxonomy FAILED