tests/readlink.py

update: warn about other topological head in pull and unbundle

Other commands have a '--update' triggering a bare update. We now issue the
message introduced into the previous changeset for these too.

#!/usr/bin/env python

import errno, os, sys

for f in sys.argv[1:]:
    try:
        print f, '->', os.readlink(f)
    except OSError as err:
        if err.errno != errno.EINVAL:
            raise
        print f, 'not a symlink'

sys.exit(0)