From f84adb5e6cf84803d9d30e36b92e7e23fa3bd5c3 Mon Sep 17 00:00:00 2001
From: RaphiMC <50594595+RaphiMC@users.noreply.github.com>
Date: Tue, 27 Feb 2024 23:44:08 +0100
Subject: [PATCH] Improved custom payload translation

---
 .../vialegacy/api/util/PacketUtil.java        |  40 +++++++
 .../Protocolc0_30toc0_30cpe.java              |   2 +-
 .../Protocol1_4_2to1_3_1_2.java               |  14 ++-
 .../Protocol1_6_2to1_6_1.java                 |   2 +-
 .../Protocol1_7_2_5to1_6_4.java               |  66 +++++------
 .../Protocol1_8to1_7_6_10.java                | 103 ++++--------------
 6 files changed, 102 insertions(+), 125 deletions(-)
 create mode 100644 src/main/java/net/raphimc/vialegacy/api/util/PacketUtil.java

diff --git a/src/main/java/net/raphimc/vialegacy/api/util/PacketUtil.java b/src/main/java/net/raphimc/vialegacy/api/util/PacketUtil.java
new file mode 100644
index 0000000..ddcb04b
--- /dev/null
+++ b/src/main/java/net/raphimc/vialegacy/api/util/PacketUtil.java
@@ -0,0 +1,40 @@
+/*
+ * This file is part of ViaLegacy - https://github.com/RaphiMC/ViaLegacy
+ * Copyright (C) 2020-2024 RK_01/RaphiMC and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package net.raphimc.vialegacy.api.util;
+
+import com.viaversion.viaversion.api.protocol.packet.PacketType;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+
+public class PacketUtil {
+
+    public static int calculateLength(final PacketWrapper wrapper) throws Exception {
+        final PacketType packetType = wrapper.getPacketType();
+        wrapper.setPacketType(null);
+
+        final ByteBuf lengthBuffer = Unpooled.buffer();
+        wrapper.writeToBuffer(lengthBuffer);
+        final int length = lengthBuffer.readableBytes();
+        lengthBuffer.release();
+
+        wrapper.setPacketType(packetType);
+        return length;
+    }
+
+}
diff --git a/src/main/java/net/raphimc/vialegacy/protocols/classic/protocolc0_28_30toc0_28_30cpe/Protocolc0_30toc0_30cpe.java b/src/main/java/net/raphimc/vialegacy/protocols/classic/protocolc0_28_30toc0_28_30cpe/Protocolc0_30toc0_30cpe.java
index 9b8a139..963ea6d 100644
--- a/src/main/java/net/raphimc/vialegacy/protocols/classic/protocolc0_28_30toc0_28_30cpe/Protocolc0_30toc0_30cpe.java
+++ b/src/main/java/net/raphimc/vialegacy/protocols/classic/protocolc0_28_30toc0_28_30cpe/Protocolc0_30toc0_30cpe.java
@@ -74,7 +74,7 @@ public class Protocolc0_30toc0_30cpe extends StatelessProtocol<ClientboundPacket
                 final PacketWrapper brand = PacketWrapper.create(ClientboundPackets1_6_4.PLUGIN_MESSAGE, wrapper.user());
                 brand.write(Types1_6_4.STRING, "MC|Brand");
                 final byte[] brandBytes = protocolMetadataStorage.getServerSoftwareName().getBytes(StandardCharsets.UTF_8);
-                brand.write(Type.SHORT, (short) brandBytes.length); // data length
+                brand.write(Type.SHORT, (short) brandBytes.length); // length
                 brand.write(Type.REMAINING_BYTES, brandBytes); // data
 
                 wrapper.send(Protocolc0_30toc0_30cpe.class);
diff --git a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_4_2to1_3_1_2/Protocol1_4_2to1_3_1_2.java b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_4_2to1_3_1_2/Protocol1_4_2to1_3_1_2.java
index 663b517..6ce9546 100644
--- a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_4_2to1_3_1_2/Protocol1_4_2to1_3_1_2.java
+++ b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_4_2to1_3_1_2/Protocol1_4_2to1_3_1_2.java
@@ -33,6 +33,7 @@ import net.raphimc.vialegacy.api.data.ItemList1_6;
 import net.raphimc.vialegacy.api.protocol.StatelessProtocol;
 import net.raphimc.vialegacy.api.remapper.LegacyItemRewriter;
 import net.raphimc.vialegacy.api.splitter.PreNettySplitter;
+import net.raphimc.vialegacy.api.util.PacketUtil;
 import net.raphimc.vialegacy.protocols.release.protocol1_4_2to1_3_1_2.rewriter.ItemRewriter;
 import net.raphimc.vialegacy.protocols.release.protocol1_4_2to1_3_1_2.rewriter.SoundRewriter;
 import net.raphimc.vialegacy.protocols.release.protocol1_4_2to1_3_1_2.types.Types1_3_1;
@@ -268,11 +269,11 @@ public class Protocol1_4_2to1_3_1_2 extends StatelessProtocol<ClientboundPackets
         this.registerClientbound(ClientboundPackets1_3_1.PLUGIN_MESSAGE, new PacketHandlers() {
             @Override
             public void register() {
-                map(Types1_6_4.STRING); // channel
                 handler(wrapper -> {
-                    final String channel = wrapper.get(Types1_6_4.STRING, 0);
-                    wrapper.passthrough(Type.SHORT); // length
-                    if (channel.equalsIgnoreCase("MC|TrList")) {
+                    final String channel = wrapper.read(Types1_6_4.STRING); // channel
+                    int length = wrapper.read(Type.SHORT); // length
+
+                    if (channel.equals("MC|TrList")) {
                         wrapper.passthrough(Type.INT); // window Id
                         final int count = wrapper.passthrough(Type.UNSIGNED_BYTE); // count
                         for (int i = 0; i < count; i++) {
@@ -283,7 +284,12 @@ public class Protocol1_4_2to1_3_1_2 extends StatelessProtocol<ClientboundPackets
                             }
                             wrapper.write(Type.BOOLEAN, false); // unavailable
                         }
+                        length = PacketUtil.calculateLength(wrapper);
                     }
+
+                    wrapper.resetReader();
+                    wrapper.write(Type.STRING, channel); // channel
+                    wrapper.write(Type.UNSIGNED_SHORT, length); // length
                 });
             }
         });
diff --git a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_6_2to1_6_1/Protocol1_6_2to1_6_1.java b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_6_2to1_6_1/Protocol1_6_2to1_6_1.java
index bbb56c7..a7aa5e4 100644
--- a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_6_2to1_6_1/Protocol1_6_2to1_6_1.java
+++ b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_6_2to1_6_1/Protocol1_6_2to1_6_1.java
@@ -46,7 +46,7 @@ public class Protocol1_6_2to1_6_1 extends StatelessProtocol<ClientboundPackets1_
             final PacketWrapper brand = PacketWrapper.create(ClientboundPackets1_6_4.PLUGIN_MESSAGE, wrapper.user());
             brand.write(Types1_6_4.STRING, "MC|Brand");
             final byte[] brandBytes = "legacy".getBytes(StandardCharsets.UTF_8);
-            brand.write(Type.SHORT, (short) brandBytes.length); // data length
+            brand.write(Type.SHORT, (short) brandBytes.length); // length
             brand.write(Type.REMAINING_BYTES, brandBytes); // data
 
             wrapper.send(Protocol1_6_2to1_6_1.class);
diff --git a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_7_2_5to1_6_4/Protocol1_7_2_5to1_6_4.java b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_7_2_5to1_6_4/Protocol1_7_2_5to1_6_4.java
index 6f2e131..f38ea6d 100644
--- a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_7_2_5to1_6_4/Protocol1_7_2_5to1_6_4.java
+++ b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_7_2_5to1_6_4/Protocol1_7_2_5to1_6_4.java
@@ -44,8 +44,6 @@ import com.viaversion.viaversion.protocols.base.ClientboundStatusPackets;
 import com.viaversion.viaversion.protocols.base.ServerboundLoginPackets;
 import com.viaversion.viaversion.protocols.base.ServerboundStatusPackets;
 import com.viaversion.viaversion.protocols.protocol1_8.ClientboundPackets1_8;
-import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelOutboundHandlerAdapter;
 import io.netty.channel.ChannelPromise;
@@ -54,6 +52,7 @@ import net.raphimc.vialegacy.api.model.IdAndData;
 import net.raphimc.vialegacy.api.protocol.StatelessTransitionProtocol;
 import net.raphimc.vialegacy.api.remapper.LegacyItemRewriter;
 import net.raphimc.vialegacy.api.splitter.PreNettySplitter;
+import net.raphimc.vialegacy.api.util.PacketUtil;
 import net.raphimc.vialegacy.protocols.release.protocol1_7_2_5to1_6_4.providers.EncryptionProvider;
 import net.raphimc.vialegacy.protocols.release.protocol1_7_2_5to1_6_4.rewriter.*;
 import net.raphimc.vialegacy.protocols.release.protocol1_7_2_5to1_6_4.storage.*;
@@ -737,10 +736,16 @@ public class Protocol1_7_2_5to1_6_4 extends StatelessTransitionProtocol<Clientbo
                 ClientboundPackets1_7_2.PLUGIN_MESSAGE, new PacketHandlers() {
                     @Override
                     public void register() {
-                        map(Types1_6_4.STRING, Type.STRING); // channel
                         handler(wrapper -> {
-                            final String channel = wrapper.get(Type.STRING, 0);
-                            wrapper.passthrough(Type.SHORT); // length
+                            final String channel = wrapper.read(Types1_6_4.STRING); // channel
+                            int length = wrapper.read(Type.SHORT); // length
+
+                            if (length < 0) {
+                                wrapper.write(Type.STRING, channel); // channel
+                                wrapper.write(Type.UNSIGNED_SHORT, 0); // length
+                                return;
+                            }
+
                             if (channel.equals("MC|TrList")) {
                                 wrapper.passthrough(Type.INT); // window id
                                 final int count = wrapper.passthrough(Type.UNSIGNED_BYTE); // count
@@ -752,7 +757,12 @@ public class Protocol1_7_2_5to1_6_4 extends StatelessTransitionProtocol<Clientbo
                                     }
                                     wrapper.passthrough(Type.BOOLEAN); // unavailable
                                 }
+                                length = PacketUtil.calculateLength(wrapper);
                             }
+
+                            wrapper.resetReader();
+                            wrapper.write(Type.STRING, channel); // channel
+                            wrapper.write(Type.UNSIGNED_SHORT, length); // length
                         });
                     }
                 }, State.LOGIN, (PacketHandler) PacketWrapper::cancel
@@ -843,7 +853,7 @@ public class Protocol1_7_2_5to1_6_4 extends StatelessTransitionProtocol<Clientbo
             wrapper.write(Type.UNSIGNED_BYTE, (short) 1); // always 1
             wrapper.write(Type.UNSIGNED_BYTE, (short) ServerboundPackets1_6_4.PLUGIN_MESSAGE.getId()); // packet id
             wrapper.write(Types1_6_4.STRING, "MC|PingHost"); // channel
-            wrapper.write(Type.UNSIGNED_SHORT, 3 + 2 * ip.length() + 4); // length
+            wrapper.write(Type.SHORT, (short) (3 + 2 * ip.length() + 4)); // length
             wrapper.write(Type.UNSIGNED_BYTE, (short) wrapper.user().getProtocolInfo().serverProtocolVersion().getVersion()); // protocol Id
             wrapper.write(Types1_6_4.STRING, ip); // hostname
             wrapper.write(Type.INT, port); // port
@@ -1030,50 +1040,34 @@ public class Protocol1_7_2_5to1_6_4 extends StatelessTransitionProtocol<Clientbo
         this.registerServerbound(ServerboundPackets1_7_2.PLUGIN_MESSAGE, new PacketHandlers() {
             @Override
             public void register() {
-                map(Type.STRING, Types1_6_4.STRING); // channel
-                map(Type.SHORT); // length
                 handler(wrapper -> {
-                    final String channel = wrapper.get(Types1_6_4.STRING, 0);
-                    final PacketWrapper lengthPacketWrapper = PacketWrapper.create(null, wrapper.user());
-                    final ByteBuf lengthBuffer = Unpooled.buffer();
+                    final String channel = wrapper.read(Type.STRING); // channel
+                    short length = wrapper.read(Type.SHORT); // length
 
                     switch (channel) {
                         case "MC|BEdit":
                         case "MC|BSign":
-                            final Item item = wrapper.read(Types1_7_6.ITEM); // book
-                            itemRewriter.handleItemToServer(item);
-
-                            lengthPacketWrapper.write(Types1_7_6.ITEM, item);
-                            lengthPacketWrapper.writeToBuffer(lengthBuffer);
-
-                            wrapper.set(Type.SHORT, 0, (short) lengthBuffer.readableBytes()); // length
-                            wrapper.write(Types1_7_6.ITEM, item); // book
+                            itemRewriter.handleItemToServer(wrapper.passthrough(Types1_7_6.ITEM));
+                            length = (short) PacketUtil.calculateLength(wrapper);
                             break;
                         case "MC|AdvCdm":
                             final byte type = wrapper.read(Type.BYTE); // command block type
                             if (type == 0) {
-                                final int posX = wrapper.read(Type.INT); // x
-                                final int posY = wrapper.read(Type.INT); // y
-                                final int posZ = wrapper.read(Type.INT); // z
-                                final String command = wrapper.read(Type.STRING); // command
-
-                                lengthPacketWrapper.write(Type.INT, posX);
-                                lengthPacketWrapper.write(Type.INT, posY);
-                                lengthPacketWrapper.write(Type.INT, posZ);
-                                lengthPacketWrapper.write(Types1_6_4.STRING, command);
-                                lengthPacketWrapper.writeToBuffer(lengthBuffer);
-
-                                wrapper.set(Type.SHORT, 0, (short) lengthBuffer.readableBytes()); // length
-                                wrapper.write(Type.INT, posX); // x
-                                wrapper.write(Type.INT, posY); // y
-                                wrapper.write(Type.INT, posZ); // z
-                                wrapper.write(Types1_6_4.STRING, command); // command
+                                wrapper.passthrough(Type.INT); // x
+                                wrapper.passthrough(Type.INT); // y
+                                wrapper.passthrough(Type.INT); // z
+                                wrapper.passthrough(Type.STRING); // command
                             } else {
                                 wrapper.cancel();
+                                return;
                             }
+                            length = (short) PacketUtil.calculateLength(wrapper);
                             break;
                     }
-                    lengthBuffer.release();
+
+                    wrapper.resetReader();
+                    wrapper.write(Types1_6_4.STRING, channel); // channel
+                    wrapper.write(Type.SHORT, length); // length
                 });
             }
         });
diff --git a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_8to1_7_6_10/Protocol1_8to1_7_6_10.java b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_8to1_7_6_10/Protocol1_8to1_7_6_10.java
index c4c3a4c..ed7c32f 100644
--- a/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_8to1_7_6_10/Protocol1_8to1_7_6_10.java
+++ b/src/main/java/net/raphimc/vialegacy/protocols/release/protocol1_8to1_7_6_10/Protocol1_8to1_7_6_10.java
@@ -46,12 +46,11 @@ import com.viaversion.viaversion.protocols.base.ClientboundLoginPackets;
 import com.viaversion.viaversion.protocols.base.ServerboundLoginPackets;
 import com.viaversion.viaversion.protocols.protocol1_8.ClientboundPackets1_8;
 import com.viaversion.viaversion.protocols.protocol1_8.ServerboundPackets1_8;
-import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 import net.raphimc.vialegacy.ViaLegacy;
 import net.raphimc.vialegacy.api.data.ItemList1_6;
 import net.raphimc.vialegacy.api.model.IdAndData;
 import net.raphimc.vialegacy.api.remapper.LegacyItemRewriter;
+import net.raphimc.vialegacy.api.util.PacketUtil;
 import net.raphimc.vialegacy.protocols.release.protocol1_7_6_10to1_7_2_5.ClientboundPackets1_7_2;
 import net.raphimc.vialegacy.protocols.release.protocol1_7_6_10to1_7_2_5.ServerboundPackets1_7_2;
 import net.raphimc.vialegacy.protocols.release.protocol1_8to1_7_6_10.data.Particle;
@@ -1110,10 +1109,14 @@ public class Protocol1_8to1_7_6_10 extends AbstractProtocol<ClientboundPackets1_
         this.registerClientbound(ClientboundPackets1_7_2.PLUGIN_MESSAGE, new PacketHandlers() {
             @Override
             public void register() {
-                map(Type.STRING); // channel
                 handler(wrapper -> {
-                    final String channel = wrapper.get(Type.STRING, 0);
-                    wrapper.read(Type.SHORT); // length
+                    final String channel = wrapper.read(Type.STRING); // channel
+                    final int length = wrapper.read(Type.UNSIGNED_SHORT); // length
+                    final int availableDataLength = PacketUtil.calculateLength(wrapper);
+                    if (availableDataLength < length) {
+                        throw new IllegalStateException("Custom payload length longer than actual data: " + length + " > " + availableDataLength);
+                    }
+                    wrapper.write(Type.STRING, channel);
 
                     switch (channel) {
                         case "MC|Brand": {
@@ -1361,9 +1364,8 @@ public class Protocol1_8to1_7_6_10 extends AbstractProtocol<ClientboundPackets1_
         this.registerServerbound(ServerboundPackets1_8.PLUGIN_MESSAGE, new PacketHandlers() {
             @Override
             public void register() {
-                map(Type.STRING); // channel
                 handler(wrapper -> {
-                    final String channel = wrapper.get(Type.STRING, 0);
+                    final String channel = wrapper.read(Type.STRING); // channel
 
                     if (ViaLegacy.getConfig().isIgnoreLong1_8ChannelNames() && channel.length() > 16) {
                         if (!Via.getConfig().isSuppressConversionWarnings()) {
@@ -1373,95 +1375,33 @@ public class Protocol1_8to1_7_6_10 extends AbstractProtocol<ClientboundPackets1_
                         return;
                     }
 
-                    final PacketWrapper lengthPacketWrapper = PacketWrapper.create(null, wrapper.user());
-                    final ByteBuf lengthBuffer = Unpooled.buffer();
-
                     switch (channel) {
                         case "MC|BEdit":
                         case "MC|BSign":
                             final Item item = wrapper.read(Type.ITEM1_8); // book
                             itemRewriter.handleItemToServer(item);
-
-                            lengthPacketWrapper.write(Types1_7_6.ITEM, item);
-                            lengthPacketWrapper.writeToBuffer(lengthBuffer);
-
-                            wrapper.write(Type.SHORT, (short) lengthBuffer.readableBytes()); // length
                             wrapper.write(Types1_7_6.ITEM, item); // book
                             break;
-                        case "MC|TrSel":
-                            final int selectedTrade = wrapper.read(Type.INT); // selected trade
-
-                            lengthPacketWrapper.write(Type.INT, selectedTrade);
-                            lengthPacketWrapper.writeToBuffer(lengthBuffer);
-
-                            wrapper.write(Type.SHORT, (short) lengthBuffer.readableBytes()); // length
-                            wrapper.write(Type.INT, selectedTrade); // selected trade
-                            break;
                         case "MC|Brand":
                         case "MC|ItemName":
                             final String content = wrapper.read(Type.STRING); // client brand or item name
-
-                            lengthPacketWrapper.write(Type.REMAINING_BYTES, content.getBytes(StandardCharsets.UTF_8));
-                            lengthPacketWrapper.writeToBuffer(lengthBuffer);
-
-                            wrapper.write(Type.SHORT, (short) lengthBuffer.readableBytes()); // length
                             wrapper.write(Type.REMAINING_BYTES, content.getBytes(StandardCharsets.UTF_8)); // client brand or item name
                             break;
                         case "MC|AdvCdm":
-                            final byte type = wrapper.read(Type.BYTE); // command block type (0 = Block, 1 = Minecart)
-                            final int posXOrEntityId;
-                            final int posY;
-                            final int posZ;
+                            final byte type = wrapper.passthrough(Type.BYTE); // command block type (0 = Block, 1 = Minecart)
                             if (type == 0) {
-                                posXOrEntityId = wrapper.read(Type.INT); // x
-                                posY = wrapper.read(Type.INT); // y
-                                posZ = wrapper.read(Type.INT); // z
+                                wrapper.passthrough(Type.INT); // x
+                                wrapper.passthrough(Type.INT); // y
+                                wrapper.passthrough(Type.INT); // z
                             } else if (type == 1) {
-                                posXOrEntityId = wrapper.read(Type.INT); // entity id
-                                posY = 0;
-                                posZ = 0;
+                                wrapper.passthrough(Type.INT); // entity id
                             } else {
                                 ViaLegacy.getPlatform().getLogger().warning("Unknown 1.8 command block type: " + type);
                                 wrapper.cancel();
-                                lengthBuffer.release();
                                 return;
                             }
-                            final String command = wrapper.read(Type.STRING); // command
+                            wrapper.passthrough(Type.STRING); // command
                             wrapper.read(Type.BOOLEAN); // track output
-
-                            lengthPacketWrapper.write(Type.BYTE, type);
-                            if (type == 0) {
-                                lengthPacketWrapper.write(Type.INT, posXOrEntityId);
-                                lengthPacketWrapper.write(Type.INT, posY);
-                                lengthPacketWrapper.write(Type.INT, posZ);
-                            } else {
-                                lengthPacketWrapper.write(Type.INT, posXOrEntityId);
-                            }
-                            lengthPacketWrapper.write(Type.STRING, command);
-                            lengthPacketWrapper.writeToBuffer(lengthBuffer);
-
-                            wrapper.write(Type.SHORT, (short) lengthBuffer.readableBytes()); // length
-                            wrapper.write(Type.BYTE, type); // type
-                            if (type == 0) {
-                                wrapper.write(Type.INT, posXOrEntityId); // x
-                                wrapper.write(Type.INT, posY); // y
-                                wrapper.write(Type.INT, posZ); // z
-                            } else {
-                                wrapper.write(Type.INT, posXOrEntityId); // entity id
-                            }
-                            wrapper.write(Type.STRING, command); // command
-                            break;
-                        case "MC|Beacon":
-                            final int primaryEffect = wrapper.read(Type.INT); // primary effect
-                            final int secondaryEffect = wrapper.read(Type.INT); // secondary effect
-
-                            lengthPacketWrapper.write(Type.INT, primaryEffect);
-                            lengthPacketWrapper.write(Type.INT, secondaryEffect);
-                            lengthPacketWrapper.writeToBuffer(lengthBuffer);
-
-                            wrapper.write(Type.SHORT, (short) lengthBuffer.readableBytes()); // length
-                            wrapper.write(Type.INT, primaryEffect); // primary effect
-                            wrapper.write(Type.INT, secondaryEffect); // secondary effect
                             break;
                         case "REGISTER":
                         case "UNREGISTER":
@@ -1486,17 +1426,14 @@ public class Protocol1_8to1_7_6_10 extends AbstractProtocol<ClientboundPackets1_
                                 channels = Joiner.on('\0').join(validChannels).getBytes(StandardCharsets.UTF_8);
                             }
 
-                            wrapper.write(Type.SHORT, (short) channels.length); // data length
                             wrapper.write(Type.REMAINING_BYTES, channels); // data
                             break;
-                        default:
-                            final byte[] data = wrapper.read(Type.REMAINING_BYTES);
-
-                            wrapper.write(Type.SHORT, (short) data.length); // data length
-                            wrapper.write(Type.REMAINING_BYTES, data); // data
-                            break;
                     }
-                    lengthBuffer.release();
+
+                    final short length = (short) PacketUtil.calculateLength(wrapper);
+                    wrapper.resetReader();
+                    wrapper.write(Type.STRING, channel); // channel
+                    wrapper.write(Type.SHORT, length); // length
                 });
             }
         });