Empty vocab select in node create when no "create access" for any terms of a vocab

Sorry for the maybe confusing title, I will explain it here :
Consider a site with to vocab A & B with terms associated. We configure a node type, let say story, to post in both vocab.
Now take a user "jack", Jack's role has the "create access" for all terms of vocab A in "categories access" but none of vocab B.
When Jack decide to create a story, he will see all granted terms from vocab A (that perfect), and he will see a empty select for vocab B. That's bad because vocab B can refer to confidential part of the site and Jack doesn't have to know that...

The problem came from taxonomy_node_form we have :

  $c = db_query("SELECT v.*, n.type FROM {vocabulary} v INNER JOIN {vocabulary_node_types} n ON v.vid = n.vid WHERE n.type = '%s' ORDER BY v.weight, v.name", $type);
  while ($vocabulary = db_fetch_object($c)) {
    $result[] = taxonomy_form($vocabulary->vid, $terms, $help, $name);
  }

The problem is that this query will select all vocabulary associated to node type without looking if user have the right to associate node with at least one of the term for all selected category.

So I propose to change the query by something a little more complicated (sorry it's very rough, I'm sure it needs a lot of improvments, but thats for the idee) :

  if (function_exists('taxonomy_access')) {
    global $user;
    $c = db_queryd("SELECT DISTINCT v. * , n.type FROM {term_access} ta INNER JOIN {term_data} td ON ta.tid = td.tid INNER JOIN {vocabulary} v ON v.vid = td.vid INNER JOIN {vocabulary_node_types} n ON v.vid = n.vid WHERE n.type = '%s' AND ta.rid IN (%s) AND ta.grant_create = 1 ORDER BY v.weight, v.name", $type, implode(',', array_keys($user->roles)));
  }
  else {
    $c = db_query("SELECT v.*, n.type FROM {vocabulary} v INNER JOIN {vocabulary_node_types} n ON v.vid = n.vid WHERE n.type = '%s' ORDER BY v.weight, v.name", $type);
  }
  
  while ($vocabulary = db_fetch_object($c)) {
    $result[] = taxonomy_form($vocabulary->vid, $terms, $help, $name);
  }

Now we only select vocab regarding of user grant for the sub terms. If user get no grant for at least a term in a given vocab, then he won't see an empty select ;)