Club Drupal

  $form['#after_build'][] = 'commerce_checkout_form_process_errors';

/**

 * After build callback for the checkout form.

 */

function commerce_checkout_form_process_errors($form, $form_state) {

  // Do this only on form rebuild (when the form will not be validated anymore):

  if (!empty($form_state['storage']['errors']) && !empty($form_state['rebuild'])) {

    foreach (array_keys($form_state['storage']['errors']) as $element_name) {

      // Look for all elements which have $element_name as parents, and

      // restore their #validated property (so _form_set_class() will set

      // the error class even though the rebuilt form is not validated).

      // We can't simply use drupal_array_get_nested_value(), since the #parents

      // property may have been changed and not match the form structure.

      _commerce_checkout_set_validated($form, $element_name);

    }

  }

  return $form;

}

/**

 * Set '#validated' on elements which have the specified parents.

 */

function _commerce_checkout_set_validated(&$element, $imploded_parents) {

  // Recurse to child elements if the current element is a container.

  foreach (element_children($element) as $key) {

    _commerce_checkout_set_validated($element[$key], $imploded_parents);

  }

  // This will also set #validated on all elements where #needs_validation would

  // be FALSE, but that doesn't hurt anything.

  if (!empty($element['#parents']) && strpos($imploded_parents, implode('][', $element['#parents'])) === 0) {

    $element['#validated'] = TRUE;

  }

}