Help Desk Ticket Reference: https://c.na7.visual.force.com/apex/Case_View?id=500A00000078xLk&sfdc.override=1
Steps to Reproduce: Execute the project JB2887.zip attached with this Jira case
securitylevel_name: Public

A rule such as
rule "MESSAGE_FINE"
salience 2
	when
		
		Message (value == "FINE")
		
		$listHolder : ListHolder()
				
		$coll1:ArrayList()
              from collect(Object() from $listHolder.getList())      
		$coll2:ArrayList()
              from collect(Object() from $listHolder.getList())
	then
	System.out.println("Exceuting rule");	
end

rule "MESSAGE_HELLO"
salience 1
	when
		msg : Message(value != "HELLO" )
	then
		msg.setValue("HELLO");
		update(msg);
		System.out.println("Message: "+msg.getValue());		
end

runs into a NPE

Caused by: java.lang.NullPointerException
	at org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:967)
	at org.drools.reteoo.AccumulateNode.splitList(AccumulateNode.java:920)
	at org.drools.reteoo.AccumulateNode.removePreviousMatchesForLeftTuple(AccumulateNode.java:874)
	at org.drools.reteoo.AccumulateNode.retractLeftTuple(AccumulateNode.java:205)
	at org.drools.reteoo.CompositeLeftTupleSinkAdapter.doPropagateRetractLeftTuple(CompositeLeftTupleSinkAdapter.java:238)
	at org.drools.reteoo.CompositeLeftTupleSinkAdapter.propagateRetractLeftTupleDestroyRightTuple(CompositeLeftTupleSinkAdapter.java:138)
	at org.drools.reteoo.AccumulateNode.retractLeftTuple(AccumulateNode.java:212)
	at org.drools.reteoo.ModifyPreviousTuples.retractTuples(ModifyPreviousTuples.java:111)
	at org.drools.reteoo.EntryPointNode.modifyObject(EntryPointNode.java:176)
	at org.drools.common.NamedEntryPoint.update(NamedEntryPoint.java:450)
	at org.drools.common.NamedEntryPoint.update(NamedEntryPoint.java:361)
	at org.drools.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:183)
	at org.drools.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:196)
	at event.Rule_launch_0.defaultConsequence(Rule_launch_0.java:7)
	at event.Rule_launch_0DefaultConsequenceInvoker.evaluate(Rule_launch_0DefaultConsequenceInvoker.java:33)
	at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:913)


A null Parameter accctx is passed down from retractLeftTuple.