NullPointerException in FlatQueryResults.<init> ("left join" query) ------------------------------------------------------------------- Key: DROOLS-1669 URL: https://issues.jboss.org/browse/DROOLS-1669 Project: Drools Issue Type: Bug Components: core engine, kie server Affects Versions: 6.5.0.Final Environment: Win7 x64, Tomcat 9, workbench-built DRL, managed KIE Server execution Reporter: Russell Morrisey Assignee: Mario Fusco The following DRL query passes build and validation in the workbench, but fails at runtime in KIE Server: {code:java} query "questionsKnowledge" () $question: Question() $visible: QuestionVisible(question == $question) or not QuestionVisible(question == $question) end {code} The intent is that $visible may or may not be bound, depending on whether QuestionVisible is present. It looks like this causes an error in FlatQueryResults.(init): {code:java} 15:59:30.897 ERROR o.k.s.s.d.DroolsKieContainerCommandServiceImpl - Error calling container 'qna2' java.lang.NullPointerException: null at org.drools.core.QueryResultsRowImpl.getFactHandle(QueryResultsRowImpl.java:99) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.drools.core.QueryResultsRowImpl.getFactHandle(QueryResultsRowImpl.java:95) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.drools.core.runtime.rule.impl.FlatQueryResults.<init>(FlatQueryResults.java:116) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.drools.core.command.runtime.rule.QueryCommand.execute(QueryCommand.java:109) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.drools.core.command.runtime.rule.QueryCommand.execute(QueryCommand.java:39) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.drools.core.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:137) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.drools.core.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:51) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.drools.core.impl.StatelessKnowledgeSessionImpl.execute(StatelessKnowledgeSessionImpl.java:254) ~[drools-core-6.5.0.Final.jar:6.5.0.Final] at org.kie.server.services.drools.RulesExecutionService.call(RulesExecutionService.java:52) ~[kie-server-services-drools-6.5.0.Final.jar:6.5.0.Final] at org.kie.server.services.drools.DroolsKieContainerCommandServiceImpl.callContainer(DroolsKieContainerCommandServiceImpl.java:69) ~[kie-server-services-drools-6.5.0.Final.jar:6.5.0.Final ] at org.kie.server.remote.rest.drools.CommandResource.manageContainer(CommandResource.java:72) [kie-server-rest-drools-6.5.0.Final.jar:6.5.0.Final] {code}