HPCC-11275 Protect against rogue options

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #5794 from ghalliday/issue11275

HPCC-11275 Protect against rogue options

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>