Allowed and forbidden tags are not set correctly

The format object in editor_format_allowed_html() does not include the text format's filters. In Editor CKEditor, this results in the ACF settings not being generated correctly.

There's a core issue, #1304930: filter_format_load doesn't seem to populate $format->filters - bug or feature? that is related to this issue. In the meantime, I think adding

<?php
if (empty($format->filters)) {
    $filters = filter_list_format($format->format);
    // Build the $format->filters array.
    $format->filters = array();
    foreach($filters as $name => $filter) {
      foreach($filter as $k => $v) {
        $format->filters[$name][$k] = $v;
      }
    }
  }
?>

In editor_format_allowed_html will consistently provide the filters. However, I'm not sure if this is the right location for it in the module.