String key = makeKey(newl);
Link oldl = oldmap.get(key);
if (oldl == null)
continue;
if (oldl.overrides(newl))
// previous information overrides this link, so ignore
curlinks.remove(newl);
else if (sameAs(oldl, newl)) {
// there's no new information here, so just ignore this
curlinks.remove(newl);