comment_admin_overview_validate($form_id, $edit)
drupal/modules/comment.module, line 986
We can't execute any 'Update options' if no comments were selected.
function comment_admin_overview_validate($form_id, $edit) {
$edit['comments'] = array_diff($edit['comments'], array(0));
if (count($edit['comments']) == 0) {
form_set_error('', t('Please select one or more comments to perform the update on.'));
drupal_goto('admin/comment');
}
}