u, err2 := decode(label[len(acePrefix):])
			if err2 != nil {
				if err == nil {
					err = err2
				}
				// Spec says keep the old label.
				continue
			}
			isBidi = isBidi || bidirule.DirectionString(u) != bidi.LeftToRight
			labels.set(u)
			if err == nil && p.fromPuny != nil {
				err = p.fromPuny(p, u)
			}
			if err == nil {
				// This should be called on NonTransitional, according to the