Wysiwyg assumes that #access on format means there is only one filter available, this is wrong and breaks format default value in hidden field

Everything is in the title: Wysiwyg assumes that #access on format means there is only one filter available, this is wrong and breaks format default value in hidden field.

This code:

  // Use a hidden element for a single text format.
  if (!$format_field['format']['#access']) {
    $format_field['wysiwyg'] = array(
      '#type' => 'hidden',
      '#name' => $format_field['format']['#name'],
      '#value' => $format_id,
      '#attributes' => array(
        'id' => $format_field['format']['#id'],
        'class' => array('wysiwyg'),
      ),
    );

Is both conceptually and alrorithmically wrong.

• Conceptually because #access to false is also valid when another module wants to force a format to be used
• Algorithmically because you should reuse the current #value or #default_value instead of the latest $format_id, which comes from a random loop and does not respect the current value.

What happens here is that this algorithm takes the element with the higher weight, erase the previsously set value and set this one instead.