C function to create tsquery not working

I'm still having trouble making this work:

http://pgsql.privatepaste.com/14a6d3075e

CREATE OR REPLACE FUNCTION tsvector_to_tsquery(IN tsv tsvector, op
IN char(1), weights IN varchar(4), maxpos IN smallint
)
RETURNS tsquery
AS 'MODULE_PATHNAME'
LANGUAGE C STRICT;

What I expect is:

tsvector_to_tsquery('java tano', '&', 'ABCD', 100) ->
java & tano

tsvector_to_tsquery('java:1A,2B tano:3C,4D', '&', 'ABC', 100) ->
java:A & java:B & tano:C

tsvector_to_tsquery('java:1A,2B tano:3C,4D', '|', 'ABC', 100) ->
java:AB | tano:C

I've made some improvement compared to previous version I've posted
but still it returns an empty tsquery.

Things that works:
- tsvector_tsquery_size returns reasonable total length of strings
and total number of (operand + operator)
- curout is actually filled with a lexeme
- filters (wf, posmax) work

--
Ivan Sergio Borgonovo
http://www.webthatworks.it