JDBC connection QueryTimeout property appears to be ignored

While testing an EDS patch, I tried to constrain a query by adding ;QueryTimeout=1 to my JDBC connection string. This had no apparent effect. (The query-a repeated UNION ALL of huge tables, followed by a descending ORDER BY-takes over 30 seconds.)

I also tried 3 and 10 second timeouts, but all allowed the query to continue to completion.