switch_tests.py 21 failing with serf

switch_tests.py 21 is failing when I use serf although it passes when
I use neon. The test involves a switch that fails because a directory
to be added is obstructed by an unversioned directory. This causes
the switch to fail and the test then fails because serf and neon do
things in different orders. For two sibling directories neon calls:

  add_directory
  close_directory
  add_directory
  close_directory

but serf calls:

  add_directory
  add_directory
  close_directory
  close_directory

The add_directory calls add an incomplete directory that is made
complete by the close_directory call. So if the second add_directory
fails the status of the first directory added depends on which http
library is in use.

I am aware that there are ordering issues with serf, is this one of
known ones?

Also, when the add_directory call in libsvn_wc returns an error back
to serf the switch doesn't immediately abort, it calls add_directory
on the failing path two more times. Is this the way it's supposed to
behave?

-- 
Philip