tests/readlink.py

convert: check for failed svn import in debugsvnlog and abort cleanly

'hg debugsvnlog' failed with a crash when using the uninitialized transport in
get_log_child if the import of the svn libraries had failed.

'convert' should never get as far as launching 'hg debugsvnlog' if the svn
libraries are missing, but by launching a subprocess there is risk that the
environment is mangled so the second import fails.

It is in principle also possible to launch the command manually.

#!/usr/bin/env python

import errno, os, sys

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

sys.exit(0)