if (s == -1)
s = pathname.length();
if (s == 0)
throw new IllegalArgumentException("pathname " + pathname);
String ns = pathname.substring(0, s);
_Jid jid = kGet(stringToKey(ns));
if (jid == null)
return null;
if (s == pathname.length())
return jid;
return jid.resolvePathname(pathname.substring(s + 1));
}