Improve handling of IPv6-only cases

app/backend/computermanager.cpp

@@ -662,7 +662,8 @@ private:
         if (m_Mdns) {
             newComputer->localAddress = m_Address;
 
-            // Get the WAN IP address using STUN if we're on mDNS
+            // Get the WAN IP address using STUN if we're on mDNS over IPv4
+            if (QHostAddress(newComputer->localAddress).protocol() == QAbstractSocket::IPv4Protocol) {
                 quint32 addr;
                 int err = LiFindExternalAddressIP4("stun.moonlight-stream.org", 3478, &addr);
                 if (err == 0) {
@@ -671,6 +672,7 @@ private:
                 else {
                     qWarning() << "STUN failed to get WAN address:" << err;
                 }
+            }
 
             if (!m_MdnsIpv6Address.isNull()) {
                 Q_ASSERT(m_MdnsIpv6Address.protocol() == QAbstractSocket::IPv6Protocol);

app/backend/nvcomputer.cpp

@@ -132,7 +132,12 @@ NvComputer::NvComputer(QString address, QString serverInfo, QSslCertificate serv
                 mode2.width * mode2.height * mode2.refreshRate;
     });
 
+    // We can get an IPv4 loopback address if we're using the GS IPv6 Forwarder
     this->localAddress = NvHTTP::getXmlString(serverInfo, "LocalIP");
+    if (this->localAddress.startsWith("127.")) {
+        this->localAddress = QString();
+    }
+
     this->remoteAddress = NvHTTP::getXmlString(serverInfo, "ExternalIP");
     this->pairState = NvHTTP::getXmlString(serverInfo, "PairStatus") == "1" ?
                 PS_PAIRED : PS_NOT_PAIRED;