CR309 - Extension type

[Subbu Allamaraju <subbu@bea.com>]

At the last F2F I was asked to explore whether an extension element 
could turn on strict validation if the extensions element specifies lax 
validation.

The objective of this change request was to keep the schema "extensible" 
and conform to the "must ignore unknown" rule of extensibility. The WSRP 
1.0 definition of the extension type breaks this rule. XML processors 
cannot ignore unknown elements if they try to validate known elements 
(i.e. elements other than extensions). Extensions and validations 
therefore cannot therefore be used simultaneously.

If the schema specifies lax validation, schema validators skip 
validation for those elements. So, we cannot force strict validation.

Andre brought a use case for keeping strict validation on extension 
elements to prevent rogue xml coming into the system, and proposed 
adding a new Extension type with lax processing.

In order to keep WSRP "strictly" extensible, we ought to relax the 
extension type. I suspect implementations will run into tricky 
production-time issues with third-party monitoring/auditing tools 
watching WSRP traffic.

I propose to make an errata item to add lax processing for extensions. 
The issue does affect 1.0 implementations.

Regards,

Subbu