text: -- original: fts1porter.test
  -- credit:   http://www.sqlite.org/src/tree?ci=trunk&name=test
  
  CREATE VIRTUAL TABLE t1 USING fts1(word, tokenize Porter)
  ;DELETE FROM t1_term;
        DELETE FROM t1_content;
        INSERT INTO t1(word) VALUES(sub_pfrom);
        SELECT term FROM t1_term;