PHP Error Detection

php_error_detection.txt

/**
 * There is a coding mistake in the code below. See if you can spot it and explain why the mistake
 * may or may not cause an issue when executed.
 */
if (!empty($form['#node']->custom_fail_message && $node->webform['redirect_url'] != '<confirmation>')) {
  drupal_get_messages('status');
  drupal_set_message(check_markup($form['#node']->custom_fail_message, 'full_html', '', TRUE));
}