CR — Ambiguous OnPart references for cross-stage-boundary plan items

Suppose we have the following case definition, expressed in XML.
<definitions>
<case name="stages" xmlns="http://www.omg.org/spec/CMMN/20121031/MODEL">
<caseRoles />
<input />
<output />
<caseFileModel />
<casePlanModel name="casePlan">
<planItem name="Stage1" definitionRef="Stage" />
<planItem name="Stage2" definitionRef="Stage" />

<planItem name="Milestone1" definitionRef="Milestone" entryCriteriaRefs="Task1Completed" />
<sentry name="Task1Completed">
<planItemOnPart sourceRef="Task1">
<standardEvent>Complete</standardEvent>
</planItemOnPart>
</sentry>

<stage name="Stage">
<planItem name="Task1" definitionRef="Task" />
</stage>
<milestone name="Milestone" />
<humanTask name="Task" />
</casePlanModel>
</case>
</definitions>

Within this case, we have a Milestone1, with an entry criterion referring to Sentry called Task1Completed.
Task1 is a plan item within Stage, hence can be referenced from the sentry.

At runtime, however, there will be 2 instances of Task1: one in Stage1, and another within Stage2 (as both have the same stage definition).

The specification does not say anything as to which instance plan item the sentry refers, making it ambiguous. Well ... in page 26, at SentryRef, the specification says that the sentry ref must refer to a plan item within the same stage. However, this is conflicting with the image on page 64, as indicated in the issue logged as "CMMN spec inconsistent with respect to Sentry dependencies crossing Stage boundaries"

Duplicate of issue CR-7

Duplicate