The Axis2 code invokes MessageContext.isFault() before starting the phases. This causes an Axiom tree to be built up to and including the
first child element (payload) in the soap body. The problem is that the phases might have special CustomBuilders. Building the Axiom tree past the payload
can defeat these kinds of optimizations.
The first solution is tactical and will work with all parsers. The proposal is to add some simple, protected "look ahead" code in the StaXOMBuilder.
The Axiom SOAPBody can use this information to determine whether the payload is a fault, without actually building the object. I am working on the tests and code for this first solution, and will have it ready in the next day or two.
The second solution is support a custom property on the parser. The SOAPEnvelope can then call the custom property on the backing parser to get the soap body payload qname. The idea is that the parser (woodstox or ibm, etc.) may have already looked ahead in the text before the StAX events are fully pulled.
The benefit of this solution is that calls, like MessageContext.isFault(), will not cause the expansion of the header elements. I will work on this solution
after solution 1 is done. I don't have a proposed name for the property yet.
(Note that both of these solutions will require some minor changes to the Axis2 code.)
P.S. I am working with Takahide Nogayama on these changes.