NULL argument to pager_query in user_admin_account

Noticed this on a site with lots of users each with lots of roles...

Expected: pager on admin/user/user displays the correct number of pages for the number of users in users table.

Observed: pager can render with more pages than are required. eg, pager shows links to 5 pages, but clicking admin/user/user?page=4 shows no users.

in function user_admin_account():

$sql = 'SELECT DISTINCT u.uid, u.name, u.status, u.created, u.access FROM {users} u LEFT JOIN {users_roles} ur ON u.uid = ur.uid '. $filter['join'] .' WHERE u.uid != 0 '. $filter['where'];
$result = pager_query($sql, 50, 0, NULL, $filter['args']);

As user_roles has one to many uid to rid, passing NULL to pager_query causes the 'SELECT DISTINCT u.uid' to be replaced with SELECT COUNT(*) causing $pager_total_items to be off in pager_query.

The attached patch is for DRUPAL-5 (user.module revision 1.745.2.15), but the code is the same in HEAD.