Long comparisons are not null-safe anymore

The following rules using '!=' will fail with ConstraintEvaluationException caused by a NullPointerException, when executed with two 'SomeEvent' instances inserted, one of them with 'null' in 'nr': package testpackage declare SomeEvent @role(event)   nr : Long end rule "R1 Not equal nr, left null " when   $e1 : SomeEvent( nr == null )    $e2 : SomeEvent( this != $e1, nr != $e1.nr )  then   System .out.println( "R1 not equal nr, $e1: " + $e1 + ", $e2: " + $e2); end rule "R2 Not equal nr, left not null " when   $e1 : SomeEvent( nr != null )    $e2 : SomeEvent( this != $e1, nr != $e1.nr )  then   System .out.println( "R2 not equal nr, $e1: " + $e1 + ", $e2: " + $e2); end Will produce: org.drools.mvel.ConstraintEvaluationException: Error evaluating constraint 'nr != $e1.nr' in [Rule "R1 Not equal nr, left null " in testpackage/testNullSafeEquals.drl] at org.drools.mvel.MVELConstraint.evaluate(MVELConstraint.java:286) at org.drools.mvel.MVELConstraint.isAllowedCachedLeft(MVELConstraint.java:246) at org.drools.core.common.DoubleBetaConstraints.isAllowedCachedLeft(DoubleBetaConstraints.java:108) at org.drools.core.phreak.PhreakJoinNode.doLeftInserts(PhreakJoinNode.java:108) at org.drools.core.phreak.PhreakJoinNode.doNode(PhreakJoinNode.java:71) ... Caused by: java.lang.NullPointerException at org.mvel2.math.MathProcessor.toLong(MathProcessor.java:653) at org.mvel2.math.MathProcessor.doOperationsSameType(MathProcessor.java:496) at org.mvel2.math.MathProcessor._doOperations(MathProcessor.java:210) at org.mvel2.math.MathProcessor.doOperations(MathProcessor.java:78) at org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:145) at org.mvel2.MVELRuntime.execute(MVELRuntime.java:85) ... end