Test: org.jbpm.test.functional.task.HumanTaskQueryFilterTest.testFilterParams fails on NPE

java.lang.NullPointerException
	at org.jbpm.services.task.impl.TaskQueryServiceImpl.applyQueryFilter(TaskQueryServiceImpl.java:81)
	at org.jbpm.services.task.impl.TaskQueryServiceImpl.getTasksAssignedAsPotentialOwner(TaskQueryServiceImpl.java:359)
	at org.jbpm.services.task.commands.GetTaskAssignedAsPotentialOwnerCommand.execute(GetTaskAssignedAsPotentialOwnerCommand.java:85)
	at org.jbpm.services.task.commands.GetTaskAssignedAsPotentialOwnerCommand.execute(GetTaskAssignedAsPotentialOwnerCommand.java:31)
	at org.jbpm.services.task.commands.TaskCommandExecutorImpl$SelfExecutionCommandService.execute(TaskCommandExecutorImpl.java:80)
	at org.jbpm.services.task.commands.TaskCommandExecutorImpl$SelfExecutionCommandService.execute(TaskCommandExecutorImpl.java:65)
	at org.drools.core.command.impl.AbstractInterceptor.executeNext(AbstractInterceptor.java:39)
	at org.jbpm.services.task.persistence.TaskTransactionInterceptor.execute(TaskTransactionInterceptor.java:88)
	at org.jbpm.services.task.persistence.TaskTransactionInterceptor.execute(TaskTransactionInterceptor.java:49)
	at org.drools.core.command.impl.AbstractInterceptor.executeNext(AbstractInterceptor.java:39)
	at org.drools.persistence.jta.TransactionLockInterceptor.execute(TransactionLockInterceptor.java:73)
	at org.drools.persistence.jta.TransactionLockInterceptor.execute(TransactionLockInterceptor.java:45)
	at org.drools.core.command.impl.AbstractInterceptor.executeNext(AbstractInterceptor.java:39)
	at org.drools.persistence.jpa.OptimisticLockRetryInterceptor.internalExecute(OptimisticLockRetryInterceptor.java:102)
	at org.drools.persistence.jpa.OptimisticLockRetryInterceptor.execute(OptimisticLockRetryInterceptor.java:83)
	at org.drools.persistence.jpa.OptimisticLockRetryInterceptor.execute(OptimisticLockRetryInterceptor.java:44)
	at org.drools.core.command.impl.AbstractInterceptor.executeNext(AbstractInterceptor.java:39)
	at org.jbpm.runtime.manager.impl.error.ExecutionErrorHandlerInterceptor.internalExecute(ExecutionErrorHandlerInterceptor.java:66)
	at org.jbpm.runtime.manager.impl.error.ExecutionErrorHandlerInterceptor.execute(ExecutionErrorHandlerInterceptor.java:52)
	at org.jbpm.runtime.manager.impl.error.ExecutionErrorHandlerInterceptor.execute(ExecutionErrorHandlerInterceptor.java:29)
	at org.drools.core.runtime.InternalLocalRunner.execute(InternalLocalRunner.java:37)
	at org.drools.core.runtime.InternalLocalRunner.execute(InternalLocalRunner.java:41)
	at org.jbpm.services.task.commands.TaskCommandExecutorImpl.execute(TaskCommandExecutorImpl.java:49)
	at org.jbpm.services.task.impl.command.CommandBasedTaskService.getTasksAssignedAsPotentialOwner(CommandBasedTaskService.java:231)
	at org.jbpm.runtime.manager.impl.task.SynchronizedTaskService.getTasksAssignedAsPotentialOwner(SynchronizedTaskService.java:915)
	at org.jbpm.test.functional.task.HumanTaskQueryFilterTest.testFilterParams(HumanTaskQueryFilterTest.java:149)
	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:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at qa.tools.ikeeper.test.IKeeperJUnitConnector$1.evaluate(IKeeperJUnitConnector.java:38)
	at org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:55)
	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:365)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:273)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:159)
	at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:384)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:345)
	at org.apache.maven.surefire.booter.ForkedBooter.execute(ForkedBooter.java:126)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:418)