prune: add tests to demonstrate issue6137
Here we can see that prune updates off to the parent revision
even when the pruned revision wasn't related with the working
directory parent.
A follow-up patch will fix this.
# 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