[Bug 3770] [F+O] available-documents returning empty sequence

http://www.w3.org/Bugs/Public/show_bug.cgi?id=3770

           Summary: [F+O] available-documents returning empty sequence
           Product: XPath / XQuery / XSLT
           Version: Candidate Recommendation
          Platform: PC
        OS/Version: Windows XP
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Functions and Operators
        AssignedTo: ashok.malhotra@oracle.com
        ReportedBy: mike@saxonica.com
         QAContact: public-qt-comments@w3.org


In section 15.5.4 (fn:doc), F+O states:

If the Available documents maps the string to an empty sequence, then the
function returns an empty sequence. 

However, XPath section 2.1.2 says that available documents is a mapping from
strings onto document nodes. It does not mention the possibility that it might
map a string to an empty sequence. 

We need to decide which is right.

I don't personally see that any useful purpose is served by allowing a string
to map to an empty sequence, and would delete this sentence from F+O.