Fix default clone destination
The default clone wasn't working:
$ hg clone hg
abort: repository hg/.hg not found!
This was because we were creating the destination directory from the
default, then checking whether it existed to determine whether to
expand the path.
#!/bin/sh
hg init
echo 123 > a
hg add a
hg commit -m "first" -d "0 0" a
mkdir sub
echo 321 > sub/b
hg add sub/b
hg commit -m "second" -d "0 0" sub/b
cat sub/b
hg co 0
cat sub/b
ls sub
true