Fix semantics of seed stats, fix Peer.IPv6() always returning true

tracker/announce.go

@@ -259,9 +259,7 @@ func appendPeers(ipv4s, ipv6s models.PeerList, ann *models.Announce, announcer *
 	for _, peer := range peers {
 		if count >= wanted {
 			break
-		}
-
-		if peersEquivalent(&peer, announcer) {
+		} else if peersEquivalent(&peer, announcer) {
 			continue
 		}
 

tracker/models/models.go

@@ -71,11 +71,11 @@ func NewPeer(a *Announce, u *User, t *Torrent) *Peer {
 }
 
 func (p *Peer) IPv4() bool {
-	return len(p.IP.To4()) == 4
+	return p.IP.To4() != nil
 }
 
 func (p *Peer) IPv6() bool {
-	return len(p.IP.To16()) == 16
+	return !p.IPv4()
 }
 
 // Torrent is a swarm for a given torrent file.