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
mkdir t
cd t
hg init
echo "[merge]" >> .hg/hgrc
echo "followcopies = 1" >> .hg/hgrc
echo foo > a
echo foo > a2
hg add a a2
hg ci -m "start" -d "0 0"
hg mv a b
hg mv a2 b2
hg ci -m "rename" -d "0 0"
echo "checkout"
hg co 0
echo blahblah > a
echo blahblah > a2
hg mv a2 c2
hg ci -m "modify" -d "0 0"
echo "merge"
hg merge -y --debug
hg status -AC
cat b
hg ci -m "merge" -d "0 0"
hg debugindex .hg/store/data/b.i
hg debugrename b