[jboss-jira] [JBoss JIRA] (JBRULES-3466) accumulate with an "and" condition results in NPE on reverse

[ https://issues.jboss.org/browse/JBRULES-3466?page=com.atlassian.jira.plug... ] Chris Dolan updated JBRULES-3466: --------------------------------- Summary: accumulate with an "and" condition results in NPE on reverse (was: sum with no matching values results in NPE on reverse) [Changed title] I finally reproduced this in a unit test! It turns out that there something about an "and" in the predicate of the accumulate function that's screwing it up. I came to that realization due to a completely different bug, that "and" and "or" clauses can trigger an off-by-one in the variable binding. (I'm working on a test case for that, but I suspect it may be the same root cause!) Here's the rule. The min() part is just legacy of a previous attempt. The "and" in the sum accumulate is what triggers it. {noformat} package org.drools.test; import org.drools.Cheese; import org.drools.Cheesery; import org.drools.Person; global java.util.List results; declare Total person : Person value : Number end rule "Total prices of cheeses liked by other people" salience 2 when $person : Person( $likes : likes ) $total : Number() from accumulate( $p : Person(likes != $likes, $l : likes) and $c : Cheese( type == $l ), sum($c.getPrice()) ) then insertLogical(new Total($person, $total)); end rule "Minimum Total" salience 1 when $min : Number() from accumulate( $p : Person(name != "Doug") and $t : Total(person == $p), min($t.getValue()) ) then results.add( $min ); end {noformat} The failing test I added to AccumulateTest. I crashes with an NPE on the retract() line. {noformat} @Test public void testAccumulateReverseModifyInsertLogical2() throws Exception { // read in the source final Reader reader = new InputStreamReader( getClass().getResourceAsStream( "test_AccumulateReverseModifyInsertLogical2.drl" ) ); final RuleBase ruleBase = loadRuleBase( reader ); final WorkingMemory wm = ruleBase.newStatefulSession(); final List results = new ArrayList(); wm.setGlobal( "results", results ); final Cheese[] cheese = new Cheese[]{ new Cheese( "stilton", 10 ), new Cheese( "stilton", 2 ), new Cheese( "stilton", 5 ), new Cheese( "brie", 15 ), new Cheese( "brie", 16 ), new Cheese( "provolone", 8 ) }; final Person alice = new Person( "Alice", "brie" ); final Person bob = new Person( "Bob", "stilton" ); final Person carol = new Person( "Carol", "cheddar" ); final Person doug = new Person( "Doug", "stilton" ); final FactHandle[] cheeseHandles = new FactHandle[cheese.length]; for ( int i = 0; i < cheese.length; i++ ) { cheeseHandles[i] = wm.insert( cheese[i] ); } final FactHandle aliceHandle = wm.insert( alice ); final FactHandle bobHandle = wm.insert( bob ); // add Carol later final FactHandle dougHandle = wm.insert( doug ); // should be ignored // alice = 31, bob = 17, carol = 0, doug = 17 // !alice = 34, !bob = 31, !carol = 65, !doug = 31 wm.fireAllRules(); System.out.println("results: " + results); assertEquals( 31, ((Number) results.get( results.size() - 1 )).intValue() ); // retract stilton=2 ==> bob = 15, doug = 15, !alice = 30, !carol = 61 wm.retract(cheeseHandles[1]); wm.fireAllRules(); System.out.println("results: " + results); assertEquals( 31, ((Number) results.get( results.size() - 1 )).intValue() ); } {noformat} Here's the NPE: {noformat} org.drools.RuntimeDroolsException: java.lang.NullPointerException at org.drools.rule.Accumulate.reverse(Accumulate.java:217) at org.drools.reteoo.AccumulateNode.removeMatch(AccumulateNode.java:902) at org.drools.reteoo.AccumulateNode.removePreviousMatchesForRightTuple(AccumulateNode.java:972) at org.drools.reteoo.AccumulateNode.retractRightTuple(AccumulateNode.java:320) at org.drools.reteoo.RightInputAdapterNode.retractLeftTuple(RightInputAdapterNode.java:190) at org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateRetractLeftTuple(SingleLeftTupleSinkAdapter.java:225) at org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateRetractRightTuple(SingleLeftTupleSinkAdapter.java:132) at org.drools.reteoo.JoinNode.retractRightTuple(JoinNode.java:172) at org.drools.reteoo.ObjectTypeNode.retractObject(ObjectTypeNode.java:283) at org.drools.reteoo.EntryPointNode.retractObject(EntryPointNode.java:354) at org.drools.common.NamedEntryPoint.retract(NamedEntryPoint.java:555) at org.drools.common.AbstractWorkingMemory.retract(AbstractWorkingMemory.java:920) at org.drools.common.AbstractWorkingMemory.retract(AbstractWorkingMemory.java:908) at org.drools.integrationtests.AccumulateTest.testAccumulateReverseModifyInsertLogical2(AccumulateTest.java:606) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222) at org.junit.runners.ParentRunner.run(ParentRunner.java:300) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) Caused by: java.lang.NullPointerException at org.drools.base.accumulators.SumAccumulateFunction.reverse(SumAccumulateFunction.java:83) at org.drools.base.accumulators.JavaAccumulatorFunctionExecutor.reverse(JavaAccumulatorFunctionExecutor.java:130) at org.drools.rule.Accumulate.reverse(Accumulate.java:208) ... 36 more {noformat} -- This message is automatically generated by JIRA. 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