Preserve client settings packets

src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java

@@ -4,11 +4,8 @@ import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.connection.backend.ServerConnection;
 import com.velocitypowered.proxy.data.ServerInfo;
 import com.velocitypowered.proxy.protocol.MinecraftPacket;
-import com.velocitypowered.proxy.protocol.packets.Chat;
-import com.velocitypowered.proxy.protocol.packets.JoinGame;
-import com.velocitypowered.proxy.protocol.packets.KeepAlive;
+import com.velocitypowered.proxy.protocol.packets.*;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
-import com.velocitypowered.proxy.protocol.packets.Respawn;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.EventLoop;
 import org.apache.logging.log4j.LogManager;
@@ -58,6 +55,11 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
             return;
         }
 
+        if (packet instanceof ClientSettings) {
+            player.setClientSettings((ClientSettings) packet);
+            // forward it on
+        }
+
         if (packet instanceof Chat) {
             Chat chat = (Chat) packet;
             if (chat.getMessage().equals("/connect")) {
@@ -106,6 +108,10 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
             player.getConnection().flush();
             currentDimension = joinGame.getDimension();
         }
+
+        if (player.getClientSettings() != null) {
+            player.getConnectedServer().getChannel().write(player.getClientSettings());
+        }
     }
 
     public void setCurrentDimension(int currentDimension) {

src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -5,6 +5,7 @@ import com.velocitypowered.proxy.data.GameProfile;
 import com.velocitypowered.proxy.protocol.packets.Chat;
 import com.velocitypowered.proxy.connection.MinecraftConnection;
 import com.velocitypowered.proxy.connection.backend.ServerConnection;
+import com.velocitypowered.proxy.protocol.packets.ClientSettings;
 import com.velocitypowered.proxy.util.ThrowableUtils;
 import com.velocitypowered.proxy.data.ServerInfo;
 import com.velocitypowered.proxy.protocol.packets.Disconnect;
@@ -28,6 +29,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation {
     private final GameProfile profile;
     private final MinecraftConnection connection;
     private ServerConnection connectedServer;
+    private ClientSettings clientSettings;
 
     public ConnectedPlayer(GameProfile profile, MinecraftConnection connection) {
         this.profile = profile;
@@ -58,6 +60,14 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation {
         return connectedServer;
     }
 
+    public ClientSettings getClientSettings() {
+        return clientSettings;
+    }
+
+    public void setClientSettings(ClientSettings clientSettings) {
+        this.clientSettings = clientSettings;
+    }
+
     public void handleConnectionException(ServerInfo info, Throwable throwable) {
         String error = ThrowableUtils.briefDescription(throwable);
         String userMessage;

src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

@@ -39,6 +39,9 @@ public enum StateRegistry {
             SERVERBOUND.register(KeepAlive.class, KeepAlive::new,
                     map(0x0C, MINECRAFT_1_12),
                     map(0x0B, MINECRAFT_1_12_1));
+            SERVERBOUND.register(ClientSettings.class, ClientSettings::new,
+                    map(0x05, MINECRAFT_1_12),
+                    map(0x04, MINECRAFT_1_12_1));
 
             CLIENTBOUND.register(Chat.class, Chat::new,
                     map(0x0F, MINECRAFT_1_12));
@@ -107,10 +110,6 @@ public enum StateRegistry {
 
             for (final PacketMapping mapping : mappings) {
                 ProtocolVersion version = this.versions.get(mapping.protocolVersion);
-                if (version == null) {
-                    version = new ProtocolVersion(mapping.protocolVersion);
-                    this.versions.put(mapping.protocolVersion, version);
-                }
                 version.packetIdToSupplier.put(mapping.id, packetSupplier);
                 version.packetClassToId.put(clazz, mapping.id);
 

src/main/java/com/velocitypowered/proxy/protocol/packets/ClientSettings.java

@@ -0,0 +1,95 @@
+package com.velocitypowered.proxy.protocol.packets;
+
+import com.velocitypowered.proxy.protocol.MinecraftPacket;
+import com.velocitypowered.proxy.protocol.ProtocolConstants;
+import com.velocitypowered.proxy.protocol.ProtocolUtils;
+import io.netty.buffer.ByteBuf;
+
+public class ClientSettings implements MinecraftPacket {
+    private String locale;
+    private byte viewDistance;
+    private int chatMode;
+    private boolean chatColors;
+    private short skinParts;
+    private int mainHand;
+
+    public String getLocale() {
+        return locale;
+    }
+
+    public void setLocale(String locale) {
+        this.locale = locale;
+    }
+
+    public byte getViewDistance() {
+        return viewDistance;
+    }
+
+    public void setViewDistance(byte viewDistance) {
+        this.viewDistance = viewDistance;
+    }
+
+    public int getChatMode() {
+        return chatMode;
+    }
+
+    public void setChatMode(int chatMode) {
+        this.chatMode = chatMode;
+    }
+
+    public boolean isChatColors() {
+        return chatColors;
+    }
+
+    public void setChatColors(boolean chatColors) {
+        this.chatColors = chatColors;
+    }
+
+    public short getSkinParts() {
+        return skinParts;
+    }
+
+    public void setSkinParts(short skinParts) {
+        this.skinParts = skinParts;
+    }
+
+    public int getMainHand() {
+        return mainHand;
+    }
+
+    public void setMainHand(int mainHand) {
+        this.mainHand = mainHand;
+    }
+
+    @Override
+    public String toString() {
+        return "ClientSettings{" +
+                "locale='" + locale + '\'' +
+                ", viewDistance=" + viewDistance +
+                ", chatMode=" + chatMode +
+                ", chatColors=" + chatColors +
+                ", skinParts=" + skinParts +
+                ", mainHand=" + mainHand +
+                '}';
+    }
+
+    @Override
+    public void decode(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion) {
+        this.locale = ProtocolUtils.readString(buf, 16);
+        this.viewDistance = buf.readByte();
+        this.chatMode = ProtocolUtils.readVarInt(buf);
+        this.chatColors = buf.readBoolean();
+        this.skinParts = buf.readUnsignedByte();
+        this.mainHand = ProtocolUtils.readVarInt(buf);
+    }
+
+    @Override
+    public void encode(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion) {
+        ProtocolUtils.writeString(buf, locale);
+        buf.writeByte(viewDistance);
+        ProtocolUtils.writeVarInt(buf, chatMode);
+        buf.writeBoolean(chatColors);
+        buf.writeByte(skinParts);
+        ProtocolUtils.writeVarInt(buf, mainHand);
+    }
+}