convert form_options_flatten() in form.inc to use new static caching API

Thinking about it some more, wouldn't it pretty straight-forward to remove the $reset param using a helper function?

Original code:

function form_options_flatten($array, $reset = TRUE) {
  static $return;

  if ($reset) {
    $return = array();
  }

  foreach ($array as $key => $value) {
    if (is_object($value)) {
      form_options_flatten($value->option, FALSE);
    }
    else if (is_array($value)) {
      form_options_flatten($value, FALSE);
    }
    else {
      $return[$key] = 1;
    }
  }

  return $return;
}

Modified code:

function form_options_flatten($array) {
  // Always reset static var when first entering the recursion
  drupal_static_reset('_form_options_flatten');
  return _form_options_flatten($array);
}

// New helper function
function _form_options_flatten($array) {
  $return = &drupal_static(__FUNCTION__);

  foreach ($array as $key => $value) {
    if (is_object($value)) {
      _form_options_flatten($value->option);
    }
    else if (is_array($value)) {
      _form_options_flatten($value);
    }
    else {
      $return[$key] = 1;
    }
  }

  return $return;
}

We'd need some documentation to make this obvious in plain language.

My webdev box runs out of memory while running the tests, but everything passes so far. So here it goes.

Rerolled patch against the comment added in #422362: convert form.inc to use new static caching API.

Thanks for catching that!

Rerolled.