Hi all,

I am upgrading an application from 5.3.0.Final to 5.4.0.Final and I am getting the following exception:
Exception executing consequence for rule "ruleThatFails" in indexingproblem.remove.me.anditworks: java.lang.UnsupportedOperationException
at org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)
at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287)
at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1212)
at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1446)
at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:710)
at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:674)
at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:230)
at com.mycompany.app.IndexingProblemMain.main(IndexingProblemMain.java:36)
Caused by: java.lang.UnsupportedOperationException
at org.drools.reteoo.BaseLeftTuple.getPrevious(BaseLeftTuple.java:480)
at org.drools.core.util.index.LeftTupleList.remove(LeftTupleList.java:114)
at org.drools.core.util.index.LeftTupleList.removeAdd(LeftTupleList.java:68)
at org.drools.reteoo.JoinNode.modifyLeftTuple(JoinNode.java:310)
at org.drools.reteoo.LeftTupleSource.doModifyLeftTuple(LeftTupleSource.java:304)
at org.drools.reteoo.LeftTupleSource.modifyLeftTuple(LeftTupleSource.java:278)
at org.drools.reteoo.JoinNode.modifyLeftTuple(JoinNode.java:437)
at org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateModifyLeftTuple(SingleLeftTupleSinkAdapter.java:205)
at org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateModifyObject(SingleLeftTupleSinkAdapter.java:235)
at org.drools.reteoo.LeftInputAdapterNode.modifyObject(LeftInputAdapterNode.java:170)
at org.drools.reteoo.SingleObjectSinkAdapter.propagateModifyObject(SingleObjectSinkAdapter.java:68)
at org.drools.reteoo.AlphaNode.modifyObject(AlphaNode.java:157)
at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateModifyObject(CompositeObjectSinkAdapter.java:507)
at org.drools.reteoo.CompositeObjectSinkAdapter.propagateModifyObject(CompositeObjectSinkAdapter.java:421)
at org.drools.reteoo.ObjectTypeNode.modifyObject(ObjectTypeNode.java:314)
at org.drools.reteoo.EntryPointNode.modifyObject(EntryPointNode.java:265)
at org.drools.common.NamedEntryPoint.update(NamedEntryPoint.java:483)
at org.drools.common.NamedEntryPoint.update(NamedEntryPoint.java:383)
at org.drools.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:337)
at indexingproblem.remove.me.anditworks.Rule_ruleThatFails_b159773c7b1a41a2a93044d2816b96ca.defaultConsequence(Rule_ruleThatFails_b159773c7b1a41a2a93044d2816b96ca.java:9)
at indexingproblem.remove.me.anditworks.Rule_ruleThatFails_b159773c7b1a41a2a93044d2816b96caDefaultConsequenceInvokerGenerated.evaluate(Unknown Source)
at indexingproblem.remove.me.anditworks.Rule_ruleThatFails_b159773c7b1a41a2a93044d2816b96caDefaultConsequenceInvoker.evaluate(Unknown Source)
at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1277)
... 6 more


I have tried to create a minimal test case that recreates this issue, here it is:
package indexingproblem.remove.me.anditworks;

declare Criteria
  processed : boolean
end

declare CheeseCriteria extends Criteria
end

rule setUp
salience 10000
when
then
        insert(new CheeseCriteria());
end

rule aaa
  when
        CheeseCriteria(  ) 
  then  
end

rule bbb
  when
        CheeseCriteria( )
  then   
end

rule ccc
  when
        CheeseCriteria(  )
  then  
end


rule eeeFalse
  when
        Criteria( processed == false )
    then
end

declare Filter
  
end

rule fffTrue
  when
        Criteria( processed == true )
        Filter(  )
    then
        
end

rule ruleThatFails
  when
        $criteria : Criteria( processed == false )
    then
        modify($criteria) {
            setProcessed(true)
        }
end

I've tried to run it on 5.5.0-SNAPSHOT, but I got the same result. Note that if you change the rule package to be "package indexingproblem" the exception is not thrown. The code for building the KnowledgeBase is standard, I haven't used any additional options. No fact is inserted only one fireAllRules call.

Please let me know if I should create a new JIRA ticket for this or if I am doing something wrong.

Thanking you in advance.
Best regards,
Michal