hgview #79255 fails when started outside of a repository [validation pending]

Traceback is:

Traceback (most recent call last):
 File "/usr/bin/hgview", line 33, in <module>
   main()
 File "/usr/lib/pymodules/python2.6/hgviewlib/application.py", line 174, in main
   repo = hg.repository(u, dir_)
 File "/usr/lib/pymodules/python2.6/mercurial/hg.py", line 94, in repository
   repo = _lookup(path).instance(ui, path, create)
 File "/usr/lib/pymodules/python2.6/mercurial/hg.py", line 79, in _lookup
   return thing(path)
 File "/usr/lib/pymodules/python2.6/mercurial/hg.py", line 20, in _local
   path = util.expandpath(util.drop_scheme('file', path))
 File "/usr/lib/pymodules/python2.6/mercurial/util.py", line 1372, in drop_scheme
   if path.startswith(sc):
AttributeError: 'NoneType' object has no attribute 'startswith'

versions are hgview 1.4.0 and mercurial 1.8.3.