had a problem with permissions_revoke_permissions

Ok , so I downloaded 2.3 and I still have a problem:
If you try to revoke permissions for a role and $new_permissions is all of the permissions for that role it revokes all but one.

function permissions_revoke_permissions($role_name, $new_permissions) {
  $permissions = array();
  $updated_permissions = '';
  $role = permissions_get_role($role_name);
  if (is_array($new_permissions)) {
    $permissions = permissions_get_permissions_for_role($role->name);
    if (count($permissions) > 0) {
      // Unset the permission from the array
      foreach ($new_permissions as $permission) {
        $index = array_search($permission, $permissions);
-        if ($index) {
+        if ($index >=0) {
          unset($permissions[$index]);
        }
      }

      // rebuild the permission string
      $updated_permissions = join(', ', $permissions);
      db_query("UPDATE {permission} SET perm = '%s' WHERE rid = %d", $updated_permissions, $role->rid);
    }
  }
  return;
}

Also, it seems that cvs is out of date.