Added guards against using searcher.doc_field_length() for a field that does not store field lengths. Update MultiFieldSorter to work with "missingfirst" and added a docstring.
Added guards against using searcher.doc_field_length() for a field that does not store
field lengths. Update MultiFieldSorter to work with "missingfirst" and added a docstring.


git-svn-id: b012e01f081ea6481df2f874d485c28c215da69f@62 b302ab98-2d32-0410-9738-bef0000a0cca

ryszard/whoosh,dokipen/whoosh,tallstreet/Whoosh-AppEngine