fix protocol detection when ipv6 fails

src/main/kotlin/com/viaversion/aas/VIAaaS.kt

@@ -53,6 +53,8 @@ private fun printSplash() {
     println("VIAaaS ${AspirinServer.version}")
 }
 
+val autoProtocolId = -2
+
 private fun initVia() {
     AspirinPlatform.initVia {
         AspirinRewind().init()
@@ -61,7 +63,7 @@ private fun initVia() {
         AspirinLegacy().init()
     }
 
-    ProtocolVersion.register(-2, "AUTO")
+    ProtocolVersion.register(autoProtocolId, "AUTO")
     registerAspirinProtocols()
 }
 

src/main/kotlin/com/viaversion/aas/handler/ConnectionData.kt

@@ -12,6 +12,7 @@ class ConnectionData(
     var state: ConnectionState = HandshakeState(),
     var frontVer: Int? = null,
     var backServerVer: Int? = null,
+    var autoDetectProtocol: Boolean = false
 ) {
     val frontHandler get() = frontChannel.pipeline()[MinecraftHandler::class.java]
     val backHandler get() = backChannel?.pipeline()?.get(MinecraftHandler::class.java)

src/main/kotlin/com/viaversion/aas/handler/state/HandshakeState.kt

@@ -8,6 +8,7 @@ import com.viaversion.aas.codec.packet.Packet
 import com.viaversion.aas.codec.packet.handshake.Handshake
 import com.viaversion.aas.config.VIAaaSConfig
 import com.viaversion.aas.handler.MinecraftHandler
+import com.viaversion.aas.autoProtocolId
 import com.viaversion.aas.mcLogger
 import com.viaversion.aas.util.AddressParser
 import com.viaversion.aas.util.StacklessException
@@ -72,7 +73,7 @@ class HandshakeState : ConnectionState {
             }
         }
 
-        val backProto = parsed.protocol ?: -2
+        val backProto = parsed.protocol ?: autoProtocolId
 
         val backAddress = parsed.serverAddress!!
         val port = parsed.port ?: VIAaaSConfig.defaultBackendPort ?: virtualPort
@@ -83,6 +84,7 @@ class HandshakeState : ConnectionState {
         val addressFromWeb = VIAaaSConfig.hostName.any { parsed.serverAddress.equals(it, ignoreCase = true) }
 
         handler.data.backServerVer = backProto
+        if (backProto == autoProtocolId) handler.data.autoDetectProtocol = true
         (handler.data.state as? LoginState)?.also {
             it.frontOnline = frontOnline
             it.backName = parsed.username

src/main/kotlin/com/viaversion/aas/handler/state/LoginState.kt

@@ -266,6 +266,7 @@ class LoginState : ConnectionState {
                     val info = AspirinServer.viaWebServer.requestAddressInfo(frontName).await()
                     backAddress = info.backHostAndPort
                     handler.data.backServerVer = info.backVersion
+                    if (info.backVersion == autoProtocolId) handler.data.autoDetectProtocol = true
                     frontOnline = info.frontOnline
                     info.backName?.also { backName = info.backName }
                 }

src/main/kotlin/com/viaversion/aas/handler/state/Util.kt

@@ -59,7 +59,7 @@ private suspend fun createBackChannel(
         mcLogger.debug("+ {} {} -> {}", state.name[0], handler.endRemoteAddress, socketAddr)
     }
     handler.data.backChannel = channel as SocketChannel
-    
+
     val packet = Handshake()
     packet.nextState = state
     packet.protocolId = handler.data.frontVer!!
@@ -74,7 +74,7 @@ private suspend fun createBackChannel(
 }
 
 private suspend fun autoDetectVersion(handler: MinecraftHandler, socketAddr: InetSocketAddress) {
-    if (handler.data.backServerVer == -2) { // Auto
+    if (handler.data.autoDetectProtocol) { // Auto
         var detectedProtocol: ProtocolVersion? = null
         try {
             detectedProtocol = withTimeout(10_000) {
@@ -85,14 +85,10 @@ private suspend fun autoDetectVersion(handler: MinecraftHandler, socketAddr: Ine
             mcLogger.debug("Stacktrace: ", e)
         }
 
-        if (detectedProtocol != null
+        handler.data.backServerVer = if (detectedProtocol != null
             && detectedProtocol.version !in arrayOf(-1, -2)
             && ProtocolVersion.isRegistered(detectedProtocol.version)
-        ) {
+        ) detectedProtocol.version else 47 // fallback 1.8
-            handler.data.backServerVer = detectedProtocol.version
-        } else {
-            handler.data.backServerVer = 47 // fallback 1.8
-        }
     }
 }
 
@@ -136,6 +132,7 @@ private suspend fun resolveBackendAddresses(hostAndPort: HostAndPort): List<Inet
     return when {
         removedEndDot.endsWith(".onion", ignoreCase = true) ->
             listOf(InetSocketAddress.createUnresolved(removedEndDot, srvResolved.port))
+
         else -> AspirinServer.dnsResolver
             .resolveAll(srvResolved.host)
             .suspendAwait()