(Exposed) filter on taxonomy term ID (with depth) produces invalid query

My situation:
- Multilingual site, using node translation to translate nodes.
- Region is a hierarchical taxonomy: country - region - department.
- "holiday_home" is a content type.
- User should be able to select holiday homes on country/region/department (implemented with an exposed filter with depth = 2).
- I use the march-28 dev version, so earlier fixed issues fixed with more or less same title do IMO not apply.

The generated query looks like:

SELECT node.title AS node_title, node.nid AS nid
FROM 
{node} node
WHERE (( (node.language IN  ('en')) AND (node.status = '1') AND (node.nid IN  (SELECT tn.nid AS nid
FROM 
{taxonomy_index} tn
LEFT OUTER JOIN {taxonomy_term_hierarchy} th ON th.tid = tn.tid
LEFT OUTER JOIN {taxonomy_term_hierarchy} th1 ON th.parent = th1.tid
LEFT OUTER JOIN {taxonomy_term_hierarchy} th2 ON th1.parent = th2.tid
WHERE ( (tn.tid = 'holiday_home') OR (th1.tid = '4') OR (th2.tid = '4') ))) AND (node.type IN  ('holiday_home')) ))
ORDER BY node_title ASC
LIMIT 25 OFFSET 0

Error:
- tn.tid = 'holiday_home': should be the tid of the term as selected by the user. This caters for the depth = 0 case

Improvements:
- the th1 and th2 joins should cater for the depth = 1 resp. depth = 2 cases. So I don't get the join on th, th1 could be joined to tn, this needs some rewriting of the query but that shouldn't be too difficult.
- don't use quotes around integers: would have uncovered this error earlier and more clearly.

Query as should/could be (note that we now compare to the parent field in the th: this allowed me to remove the extra join):

SELECT node.title AS node_title, node.nid AS nid
FROM 
{node} node
WHERE (( (node.language IN  ('en'))
  AND (node.status = '1')
  AND (node.nid IN  (SELECT tn.nid AS nid
    FROM ms_taxonomy_index tn
    LEFT OUTER JOIN ms_taxonomy_term_hierarchy th1 ON th1.tid = tn.tid
    LEFT OUTER JOIN ms_taxonomy_term_hierarchy th2 ON th2.tid = th1.parent
    WHERE ( (tn.tid = 4) OR (th1.parent = 4) OR (th2.parent = 4) )))
  AND (node.type IN  ('holiday_home')) ))
ORDER BY node_title ASC
LIMIT 25 OFFSET 0