Use of MIME multipart for zero payload containers

The MS spec seems to say that an ebXML message is always represented
as a MIME multipart/related entity.  There does not seem to be an
exception for the case where there are zero payload containers: in
such a case it looks like an ebXML message MUST be expressed as a MIME
multipart with only one part.  Is that right?

I mention this because I was looking at Sun's JAXM EA2 implementation,
and it seems to have logic saying that if it finds itself generating a
SOAP-with-attachments message with zero attachments, it uses the
original SOAP format, which does not use MIME multipart.  This means
that if you asked it to generate an ebXML message for which there are
no payload containers, what it would generate would not be ebXML MS
compliant.

I brought this up with the JAXM group and got this response:
Date: Fri, 14 Sep 2001 15:04:12 -0700
From: Nicholas Kassem <>

Dan,

Once again thanks for your input. I believe I now understand your point. In

the JAXM context I don't think we will gain much by dwelling on the

*interpretation* of the numerous relevant specs.  The key issue is what is

the canonical form of an ebXML 1.0 message in cases where there is only one

part in a multipart/related message. Your contention is that the presence

of an empty attachment (equivalent to no ebXML payload) may lead to

interoperability problems. I'm not convinced, but be that as it may. So, we

will include a facility in JAXM to *explicitly* use multipart/related

packaging even in cases where it is logically redundant. Hope this helps.

Nick

--
Dan