Log Message:
-----------
Avoid core dump on empty thesaurus dictionary.
Per report from Robert Gravsj.
Modified Files:
--------------
pgsql/src/backend/tsearch:
dict_thesaurus.c (r1.14 -> r1.15)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/tsearch/dict_thesaurus.c?r1=1.14&r2=1.15)