Hi Davide, I've got a null pointer exception with defeasible. My test case is: package com.sample declare Fact fact: String @key end rule init when then System.out.println("inserting initial facts"); insert( new Fact( "one" ) ); insert( new Fact( "two" ) ); insert( new Fact( "two" ) ); end rule rule1 @Defeasible enabled true when Fact( "one"; ) then System.out.println("one causes wibble"); insertLogical( new Fact( "wibble") ); end rule rule2 @Defeasible when Fact( "two"; ) then System.out.println("two causes wibble"); insertLogical( new Fact( "wibble") ); end rule rule3 @Defeater @Defeats( "rule2" ) when Fact( "two"; ) then System.out.println("two negates wibble"); insertLogical( new Fact( "wibble"), "neg" ); end The output I get is inserting initial facts one causes wibble two causes wibble two causes wibble two negates wibble two negates wibble Exception executing consequence for rule "rule3" in com.sample: java.lang.NullPointerException at org.drools.core.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39) at org.drools.core.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1057) at org.drools.core.phreak.RuleExecutor.fire(RuleExecutor.java:152) at org.drools.core.phreak.RuleExecutor.evaluateNetworkAndFire(RuleExecutor.java:94) at org.drools.core.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:964) at org.drools.core.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1234) at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1239) at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1212) at com.sample.DroolsTest.main(DroolsTest.java:21) Caused by: java.lang.NullPointerException at org.drools.core.beliefsystem.defeasible.DefeasibleBeliefSet.removeUndefeated(DefeasibleBeliefSet.java:295) at org.drools.core.beliefsystem.defeasible.DefeasibleBeliefSet.add(DefeasibleBeliefSet.java:126) at org.drools.core.beliefsystem.jtms.JTMSBeliefSystem.insert(JTMSBeliefSystem.java:52) at org.drools.core.beliefsystem.defeasible.DefeasibleBeliefSystem.insert(DefeasibleBeliefSystem.java:45) at org.drools.core.common.TruthMaintenanceSystem.addLogicalDependency(TruthMaintenanceSystem.java:136) at org.drools.core.common.TruthMaintenanceSystem.addLogicalDependency(TruthMaintenanceSystem.java:107) at org.drools.core.common.NamedEntryPoint.insert(NamedEntryPoint.java:234) at org.drools.core.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:1430) at org.drools.core.base.DefaultKnowledgeHelper.insertLogical(DefaultKnowledgeHelper.java:275) at org.drools.core.base.DefaultKnowledgeHelper.insertLogical(DefaultKnowledgeHelper.java:247) at com.sample.Rule_rule32132126114.defaultConsequence(Rule_rule32132126114.java:8) at com.sample.Rule_rule32132126114DefaultConsequenceInvokerGenerated.evaluate(Unknown Source) at com.sample.Rule_rule32132126114DefaultConsequenceInvoker.evaluate(Unknown Source) at org.drools.core.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1046) ... 7 more I believe I am using snapshot 6.1.0.201407170510 but I suspect the precise version doesn't matter too much. In the above example, if you disable rule1 then the NPE doesn't happen. Only doing one "two" fact insertion in the init rule likewise means the NPE doesn't happen. I think the issue is something like rule3 does more than one defeat on rule2's scoring on "wibble" fact, but rule1 still has a say in the continuing existence of the "wibble" fact. Should I get a Jira log in and enter these well qualified bugs directly? Regards, Borris _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

On 22/07/2014 22:44, Mark Proctor wrote: > Stack trace shows the error: > org.drools.core.beliefsystem.defeasible.DefeasibleBeliefSet.removeUndefeated(DefeasibleBeliefSet.java:295) > https://github.com/sotty/drools/blob/master/drools-core/src/main/java/org... > > Maybe have a go fixing it yourself? And submit the fix with a unit test, as a pull request? > http://docs.jboss.org/drools/release/5.6.0.Final/droolsjbpm-introduction-... > I might well have a go, but there's a whole bunch of learning I need to do before I can submit my first candidate patch. So don't expect something too quickly.

Borris _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Fixed, in PR status. It was indeed another bug. https://github.com/sotty/drools/commit/7941a0c8d7e66c6c7719c14ca58d798337... Thanks for reporting, we really appreciate the feedback Davide On 07/23/2014 10:58 PM, Borris wrote: > On 22/07/2014 22:44, Mark Proctor wrote: >> Stack trace shows the error: >> org.drools.core.beliefsystem.defeasible.DefeasibleBeliefSet.removeUndefeated(DefeasibleBeliefSet.java:295) >> https://github.com/sotty/drools/blob/master/drools-core/src/main/java/org... >> >> Maybe have a go fixing it yourself? And submit the fix with a unit test, as a pull request? >> http://docs.jboss.org/drools/release/5.6.0.Final/droolsjbpm-introduction-... >> > I might well have a go, but there's a whole bunch of learning I need to > do before I can submit my first candidate patch. So don't expect > something too quickly. > > Borris > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users