partially parsed attrs in sax_ltx

      ♢ ltx with SaxLtx 
      
      SAX parsing
        ✗ XMPP stream 
            » expected '556890365', 
            got      undefined (==) // parse-test.js:149
        ✗ bug: partial attrs 
            » expected 'urn:ietf:params:xml:ns:xmpp-sasl', 
            got      undefined (==) // parse-test.js:149

attrName gets undefined