Description of problem:

When compiling the following DRL:

package ...

import java.util.Date
import java.util.List

global List dates

rule "intervalRule"
  timer(int: 200ms 100ms)
when
  String(this == "intervalRule")
then
  Date date = new Date();
  dates.add(date);
end


// this rule stops timer
rule "stopIntervalRule"
  timer(int: 320ms)
when
  $s : String(this == "intervalRule")
then
  retract($s);
end

The following NPE is thrown:

java.lang.NullPointerException: null
	at org.drools.core.reteoo.TimerNode.equals(TimerNode.java:170)
	at org.drools.core.reteoo.SingleLeftTupleSinkAdapter.getMatchingNode(SingleLeftTupleSinkAdapter.java:159)
	at org.drools.core.reteoo.builder.BuildUtils.attachNode(BuildUtils.java:122)
	at org.drools.core.reteoo.builder.TimerBuilder.build(TimerBuilder.java:68)
	at org.drools.core.reteoo.builder.ReteooRuleBuilder.addSubRule(ReteooRuleBuilder.java:170)
	at org.drools.core.reteoo.builder.ReteooRuleBuilder.addRule(ReteooRuleBuilder.java:136)
	at org.drools.core.reteoo.ReteooBuilder.addRule(ReteooBuilder.java:112)
	at org.drools.core.reteoo.ReteooRuleBase.addRule(ReteooRuleBase.java:429)
	at org.drools.core.common.AbstractRuleBase.addRule(AbstractRuleBase.java:924)
	at org.drools.core.common.AbstractRuleBase.addPackages(AbstractRuleBase.java:600)
	at org.drools.core.reteoo.ReteooRuleBase.addPackages(ReteooRuleBase.java:456)
	at org.drools.core.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:152)
	at org.drools.compiler.kie.builder.impl.KieContainerImpl.createKieBase(KieContainerImpl.java:133)
	at org.drools.compiler.kie.builder.impl.KieContainerImpl.getKieBase(KieContainerImpl.java:81)


Version-Release number of selected component (if applicable):

Drools 6.0.0-SNAPSHOT
Drools 6.0.0.Beta4

This worked in 6.0.0.Beta3, marking as regression.


Additional info:

The stacktrace contains classes from package org.drools.core.reteoo - should they be there when using phreak?