In a catch22 using a NOT constraint in rules shared by multiple facts --------------------------------------------------------------------- Key: DROOLS-731 URL: https://issues.jboss.org/browse/DROOLS-731 Project: Drools Issue Type: Feature Request Components: core engine Affects Versions: 6.0.1.Final, 6.1.0.Final Environment: Custom application that completely wraps Drools Fusion written as an OSGI application hosted on Websphere Liberty profile. Reporter: Bill Tuminaro Assignee: Mario Fusco Attachments: DROOLS-731_DroolsTestCases.zip I have a reproducer for these related issues. We have encountered a couple of issues (Exceptions) when using a NOT constraint in rules that have facts associated with them when we call upgradeToVersion() or kSession.delete(). The catch22 is that one version of the NOT constraint avoids one Exception while causing another. Reproducing the issue requires 2 rules sharing the same NOT constraint. I have narrowed the issue(s) down to 2 very simple rules that use the org.drools.compiler.FactA class. Here are the 2 rules used: static final String ruleDrl = "package org.some.test\n" + "import org.drools.compiler.FactA\n" + "declare FactA\n" + "@role(event)" + "end\n" + "rule \"R200_0\" when\n" + // " $FactA : FactA ($FactA_field2 : field2 == 111002)\n" + // version A: using this version causes a NPE when calling ksession.delete() " not FactA($FactA_field2 == 111002, this after $FactA)\n" + " not FactA(field2 == 105742, this after $FactA)\n" + // Version B: using this version causes the IllegalArgumentException: Cannot remove a sink, // when the list of sinks is null on the updateToVersion() call "then\n" + "end\n"; static final String ruleDrl2 = "package org.some.test\n" + "import org.drools.compiler.FactA\n" + "declare FactA\n" + "@role(event)" + "end\n" + "rule \"R1437_0\" when\n" + " $FactA : FactA ($FactA_field2 : field2 == 105742)\n" + " not FactA($FactA_field2 == 105742, this after $FactA)\n" + // version A: // " not FactA(field2 == 105742, this after $FactA)\n" + // Version B: "then\n" + "end\n";