Rule group activation by concurrent jbpm processes ...

We've been able to see that the following statement in the documentation doesn't seem to be true:

"We have added special logic to make sure that a variable processInstance of type WorkflowProcessInstance
will only match to the current process instance and not to other process instances in the Working Memory."

We've seen rules fire for rule-group activations from different workflowprocesses.

Imagine a knowledge session with this set of rules:

rule "new case"
when
$object : Object(processed==false) from entry-point "my stream"
then
ProcessInstance processInstance=kcontext.getKnowledgeRuntime().createProcessInstance("my.Process", parameters);
insert(processInstance);
end

rule "complete"
ruleflow-group "process complete"
no-loop true
when
$processInstance: WorkflowProcessInstance()
then
System.out.println("Fired!" + $processInstance);
end

And a process that runs a time consuming task before reaching a bussinessruletask node that calls the "process complete" group of rules.

What is happening from Drool's expert point of view is the following sequence of events:

1 - A fact is inserted that triggers the rule "new case". An Activation is inserted into the agenda.

2 - As this is running in a fireUntilHalt loop then, almost inmediatelly, the previous activation is fired and it's consquence is evaluated leading to the insertion of the process instance as a fact in the knowledge session. The process is now executing.

3 - This very new fact triggers the activation of the rule "complete" ( as it's only condition is that a processinstance exists ). It's consequence gets evaluated and as it belongs to a group of rules, an Activation is added to the ruleFlowGroup inside the Agenda. Nothing happens thereafter.

4 - Another fact of the same type arrives and steps 1,2 and 3 execute for the new fact. Now, the agenda has two Activations stored in the ruleFlowGroup.

5 - At this time, the task in the first process ends, the businessruletask gets executed and JBPM calls "activateRuleFlowGroup" on the Agenda and the rule flow group gets activated.

6 - Inmediatelly the group of rules fires two activations ( both queued at process fact insertion when the process was started ), when only one process ended.

7 - So at least one rule gets evaluated for a process instance that didn't belong to it ..

Then , "We have added special logic to make sure that a variable processInstance of type WorkflowProcessInstance
will only match to the current process instance and not to other process instances in the Working Memory." doesn't hold to be true, as our rule is fired before it's process asks Drools to do so.

We've tested this behaviour in Drools 5.1.0, 5.2.0 and 5.3.0. All seem to fail in fulfilling the requirements stated the documentation.