[wp-hackers] Querying posts inside hierarchical custom taxonomy

[Malaiac]

Custom taxonomy for posts is "places".
Hierarchy is like
Europe
  France
  Germany
Asia
  Vietnam

I can query posts from "France" or "Vietnam".
How should I query posts to get all those from Europe or Asia ?
There is no children term query inside wp_query (query.php, around
line 1947, there is : $terms = get_terms($q['taxonomy'],
array('slug'=>$q['term'])); , with no way to ask for children terms).

Malaiac