From f04599ae68baca55f98db5beaf4168164e7c13ed Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Sat, 29 Sep 2018 01:28:07 -0400
Subject: [PATCH] Clean up some plugin message channel code

---
 .../client/ClientPlaySessionHandler.java          | 15 ++++-----------
 .../proxy/protocol/util/PluginMessageUtil.java    | 10 +++++-----
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java
index 810899956..35b2b7efe 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java
@@ -44,13 +44,8 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
 
     @Override
     public void activated() {
-        PluginMessage message;
-        if (player.getProtocolVersion() >= ProtocolConstants.MINECRAFT_1_13) {
-            message = PluginMessageUtil.constructChannelsPacket("minecraft:register", server.getChannelRegistrar().getModernChannelIds());
-        } else {
-            message = PluginMessageUtil.constructChannelsPacket("REGISTER", server.getChannelRegistrar().getIdsForLegacyConnections());
-        }
-        player.getConnection().write(message);
+        PluginMessage register = PluginMessageUtil.constructChannelsPacket(player.getProtocolVersion(), server.getChannelRegistrar().getModernChannelIds());
+        player.getConnection().write(register);
     }
 
     @Override
@@ -213,10 +208,8 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
             toRegister.addAll(server.getChannelRegistrar().getIdsForLegacyConnections());
         }
         if (!toRegister.isEmpty()) {
-            String channel = player.getConnection().getProtocolVersion() >= ProtocolConstants.MINECRAFT_1_13 ?
-                    "minecraft:register" : "REGISTER";
             player.getConnectedServer().getConnection().delayedWrite(PluginMessageUtil.constructChannelsPacket(
-                    channel, toRegister));
+                    player.getConnection().getProtocolVersion(), toRegister));
         }
 
         // If we had plugin messages queued during login/FML handshake, send them now.
@@ -267,7 +260,7 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
             }
 
             if (actuallyRegistered.size() > 0) {
-                PluginMessage newRegisterPacket = PluginMessageUtil.constructChannelsPacket(packet.getChannel(), actuallyRegistered);
+                PluginMessage newRegisterPacket = PluginMessageUtil.constructChannelsPacket(player.getProtocolVersion(), actuallyRegistered);
                 player.getConnectedServer().getConnection().write(newRegisterPacket);
             }
         } else if (PluginMessageUtil.isMCUnregister(packet)) {
diff --git a/proxy/src/main/java/com/velocitypowered/proxy/protocol/util/PluginMessageUtil.java b/proxy/src/main/java/com/velocitypowered/proxy/protocol/util/PluginMessageUtil.java
index 1ffb37dc9..45a682fd1 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/protocol/util/PluginMessageUtil.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/protocol/util/PluginMessageUtil.java
@@ -2,6 +2,7 @@ package com.velocitypowered.proxy.protocol.util;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.velocitypowered.proxy.protocol.ProtocolConstants;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.PluginMessage;
 import io.netty.buffer.ByteBuf;
@@ -37,12 +38,11 @@ public enum PluginMessageUtil {
         return ImmutableList.copyOf(channels.split("\0"));
     }
 
-    public static PluginMessage constructChannelsPacket(String channel, Collection<String> channels) {
-        Preconditions.checkNotNull(channel, "channel");
-        Preconditions.checkNotNull(channel, "channels");
-
+    public static PluginMessage constructChannelsPacket(int protocolVersion, Collection<String> channels) {
+        Preconditions.checkNotNull(channels, "channels");
+        String channelName = protocolVersion >= ProtocolConstants.MINECRAFT_1_13 ? "minecraft:register" : "REGISTER";
         PluginMessage message = new PluginMessage();
-        message.setChannel(channel);
+        message.setChannel(channelName);
         message.setData(String.join("\0", channels).getBytes(StandardCharsets.UTF_8));
         return message;
     }