Fix handling of paths when run outside the repo. The main problem was that dirstate.getcwd() returned just "", which was interpreted as "we're at the repo root". It now returns an absolute path. The util.pathto function was also changed to deal with the "cwd is an absolute path" case.

#!/bin/sh
# http://www.selenic.com/mercurial/bts/issue433

hg init a
cd a       
echo a > a 
hg commit -Ama 

hg parents -r 0 doesnotexist
true