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<div class=WordSection1><pre>I am pretty sure this is a bug, but would like confirmation from people more familiar with the code base. My tests seem to show that RuleTerminalNode can cause an NPE on two different lines of code. Both places where a call is made to “workingMemory.getTruthMaintenanceSystem()” in that class can result in a null pointer exception if the “maintainTms” option is false. In my case I discovered the issue in some unit tests where I am calling “<span
style='color:#0000C0;background:silver;mso-highlight:silver'>knowledgeBase</span><span
style='color:black;background:silver;mso-highlight:silver'>.removeKnowledgePackage</span><span
style='color:black'>” which ends up (eventually) in RuleTerminalNode. I have pasted an example stack trace below:<o:p></o:p></span></pre><pre><span
style='color:black'><o:p> </o:p></span></pre><pre>Thread [main] (Suspended (exception NullPointerException)) <o:p></o:p></pre><pre> RuleTerminalNode$RTNCleanupAdapter.cleanUp(LeftTuple, InternalWorkingMemory) line: 519 <o:p></o:p></pre><pre> ObjectTypeNode.doRemove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 347 <o:p></o:p></pre><pre> ObjectTypeNode.remove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 325 <o:p></o:p></pre><pre> AlphaNode(ObjectSource).doRemove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 209 <o:p></o:p></pre><pre> AlphaNode(BaseNode).remove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 109 <o:p></o:p></pre><pre> LeftInputAdapterNode.doRemove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 187 <o:p></o:p></pre><pre> LeftInputAdapterNode(BaseNode).remove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 109 <o:p></o:p></pre><pre> RuleTerminalNode.doRemove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 411 <o:p></o:p></pre><pre> RuleTerminalNode(BaseNode).remove(RuleRemovalContext, ReteooBuilder, BaseNode, InternalWorkingMemory[]) line: 109 <o:p></o:p></pre><pre> ReteooBuilder.removeRule(Rule) line: 237 <o:p></o:p></pre><pre> ReteooRuleBase.removeRule(Rule) line: 432 <o:p></o:p></pre><pre> ReteooRuleBase(AbstractRuleBase).removeRule(Package, Rule) line: 831 <o:p></o:p></pre><pre> ReteooRuleBase(AbstractRuleBase).removePackage(String) line: 751 <o:p></o:p></pre><pre> KnowledgeBaseImpl.removeKnowledgePackage(String) line: 201 <o:p></o:p></pre>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>(I redacted the stack after the call to
removeKnowledgePackage() because it provides no value in this discussion)<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I am using Drools 5.1.1. I have also looked at the latest
version of the code here:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>https://github.com/droolsjbpm/droolsjbpm/blob/master/drools-core/src/main/java/org/drools/reteoo/RuleTerminalNode.java<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Can anyone confirm that this is a bug, or if not tell me
what I am doing wrong?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thank You,<o:p></o:p></p>
<p class=MsoNormal>Nathan Bell<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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