Currently, the repository states that it does support document order, but an XPath expression that uses the 'position()' or 'last()' functions will not work. Support for document order is optional per the JCR 1.0 specification [1], but because we're stating that we do support document order by returning true from Repository.getDescriptor(QUERY_XPATH_DOC_ORDER). Several TCK unit test use the descriptor value to determine whether the tests should be performed, so they currently fail.

Therefore, we should either support the 'position()' and 'last()' functions or return 'false' from Repository.getDescriptor(QUERY_XPATH_DOC_ORDER).

[1] Section 6.6.6.3 mentions "Required function support ([42] and [60] above) is limited to the functions described in 6.6.5 XPath Extensions", but 6.6.5 does not mention position() or last(). These functions are addressed in section 6.6.4.2 that addressed document order.