[wsbpel] Issue 250 - Proposal for Vote

[Rania Khalaf <rkhalaf@watson.ibm.com>]

CURRENT TEXT ON EXTENSION ACTIVITY IN SECTION 10:

If the element contained within the extensionActivity element is not
recognized by the BPEL processor and is not subject to a
mustUnderstand="yes" requirement from an extension declaration then
the unknown activity MUST be treated as if it were an empty
activity. In all cases however any standard-attributes or
standard-elements used on the contained activity MUST be treated as
defined by this specification.

INSERT AS BEFORE TO LAST SENTENCE (between 'empty activty' and 'in all 
cases'):

In such a case (where the <extensionActivity> is treated as <empty>)
all enclosed artifacts, including links, in the <extensionActivity>
are not visible to a processor that does not understand the
extension. To avoid dangling links in these situations, the following
restriction must be met. If a link crosses the boundary of an
<extensionActivity>, then the element contained within the
<extensionActivity> MUST be subject to mustUnderstand="yes".

Implementers note: This can be detected if a processor that does not
understand certain extensionActivities replaces them with <empty>
activities *before* doing static validation.