Default Taxonomy View Treats + and , Identically

According to the Taxonomy page, the , argument between two taxonomy terms functions as AND while the + argument functions as OR.

However, the taxonomy_term view that comes packages while Views treats them both as OR. The query generated for 10+17 and 10,17 is:

SELECT node.nid AS nid,
   node.sticky AS node_sticky,
   node.created AS node_created
 FROM node node 
 WHERE (node.status <> 0 OR node.uid = ***CURRENT_USER*** or ***ADMINISTER_NODES*** = 1) AND (node.vid IN (
  SELECT tn.vid FROM term_node tn
  WHERE tn.tid  IN (10, 17)
  ))
   ORDER BY node_sticky DESC, node_created DESC

My initial suspicion is that replacing

WHERE ..... AND (node.vid IN (
  SELECT tn.vid FROM term_node tn
  WHERE tn.tid  IN (10, 17)
  )

with

WHERE ..... AND (node.vid IN (
  SELECT tn.vid FROM term_node tn
  WHERE tn.tid  = 10) AND  (node.vid IN (
  SELECT tn.vid FROM term_node tn
  WHERE tn.tid  = 17)
  )

would fix the problem. However, I don't know enough about the internal workings of Views to implement the switch between the two queries based on the arguments passed in by the URL.

I didn't attach an export of the view, since it's one that comes packaged by default. It's worth noting that when activated, this view overrides Drupal's default handling of the taxonomy/term/ pages, so you essentially lose the , functionality entirely.