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
hg --debug init
echo this is a1 > a
hg add a
hg commit -m0 -d "1000000 0"
echo this is b1 > b
hg add b
hg commit -m1 -d "1000000 0"
hg manifest --debug 1
echo this is c1 > c
hg rawcommit -p 1 -d "1000000 0" -m2 c
hg manifest --debug 2
hg -v parents
rm b
hg rawcommit -p 2 -d "1000000 0" -m3 b
hg manifest --debug 3
hg -v parents
echo this is a22 > a
hg rawcommit -p 3 -d "1000000 0" -m4 a
hg manifest --debug 4
hg -v parents
echo this is c22 > c
hg rawcommit -p 1 -d "1000000 0" -m5 c
hg manifest --debug 5
hg -v parents
# merge, but no files changed
hg rawcommit -p 4 -p 5 -d "1000000 0" -m6
hg manifest --debug 6
hg -v parents
# no changes what-so-ever
hg rawcommit -p 6 -d "1000000 0" -m7
hg manifest --debug 7
hg -v parents