Code review comment for lp:~xaav/loggerhead/export-tarball

Okay, I've fixed some stuff (the tests are still broken), but here is what I'm getting:

Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 1068, in process_request_in_thread
    self.finish_request(request, client_address)
  File "C:\Python27\lib\SocketServer.py", line 323, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "C:\Python27\lib\SocketServer.py", line 639, in __init__
    self.handle()
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 442, in handle
    BaseHTTPRequestHandler.handle(self)
  File "C:\Python27\lib\BaseHTTPServer.py", line 337, in handle
    self.handle_one_request()
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 437, in handle_one_request
    self.wsgi_execute()
  File "C:\Python27\lib\site-packages\paste-1.7.5.1-py2.7.egg\paste\httpserver.py", l
ine 289, in wsgi_execute
    for chunk in result:
  File "C:\Users\Xaav\workspace\loggerhead\loggerhead\exporter.py", line 31, in e
xport_archive
    for _ in get_export_generator(tree=tree, fileobj=fileobj, format=format):
  File "C:\Python27\lib\site-packages\bzrlib\export\__init__.py", line 112, in get_ex
port_generator
    root = get_root_name(dest)
  File "C:\Python27\lib\site-packages\bzrlib\export\__init__.py", line 174, in get_ro
ot_name
    dest = os.path.basename(dest)
  File "C:\Python27\lib\ntpath.py", line 198, in basename
    return split(p)[1]
  File "C:\Python27\lib\ntpath.py", line 170, in split
    d, p = splitdrive(p)
  File "C:\Python27\lib\ntpath.py", line 125, in splitdrive
    if p[1:2] == ':':
TypeError: 'NoneType' object is not subscriptable

Any help would be appreciated.