topic: make revsets like foo#stack[-1] work too
We remove base commit when n < 0 because it's confusing to see base (which
technically isn't a commit inside the stack) at both 0 and -n.
# utility to setup pythonpath to point into the tested repository
export SRCDIR=`dirname $TESTDIR`
if [ -n "$PYTHONPATH" ]; then
export HGTEST_ORIG_PYTHONPATH=$PYTHONPATH
export PYTHONPATH=$SRCDIR:$PYTHONPATH
else
export PYTHONPATH=$SRCDIR
fi