Error in SQL query in function _relatedlinks_search_select_nodes

At line 830 the query reads:

$result = db_query_range("SELECT DISTINCT(si.word) FROM {search_index} si INNER JOIN {search_total} st USING (word) WHERE si.sid = %d AND length(si.word) > %d AND si.type     = 'node' ORDER BY st.count DESC, length(si.word) DESC", $nid, variable_get('minimum_word_size', 3), 0, 6);

however, at least in PostgreSQL (but I think also in standard SQL) if SELECT DISTINT is used you should have ORDER BY attributes in SELECT attribute list

Thus I obtain the following error
pg_query() [function.pg-query]: Query failed: ERROR: for SELECT DISTINCT, ORDER BY expressions must appear in select list in /home/www-data/castelnuovobga/vhproduction/drupal-6.25/includes/database.pgsql.inc

I'm providing a patch for this issue.
In my environment it works correctly and I'm tried to copy surrounding coding style, however please test it.