#3846, #3847: Handle packet bundles

protocol/src/main/java/net/md_5/bungee/protocol/AbstractPacketHandler.java

@@ -1,6 +1,7 @@
 package net.md_5.bungee.protocol;
 
 import net.md_5.bungee.protocol.packet.BossBar;
+import net.md_5.bungee.protocol.packet.BundleDelimiter;
 import net.md_5.bungee.protocol.packet.Chat;
 import net.md_5.bungee.protocol.packet.ClearDialog;
 import net.md_5.bungee.protocol.packet.ClearTitles;
@@ -293,4 +294,8 @@ public abstract class AbstractPacketHandler
     public void handle(CustomClickAction customClickAction) throws Exception
     {
     }
+
+    public void handle(BundleDelimiter bundleDelimiter) throws Exception
+    {
+    }
 }

protocol/src/main/java/net/md_5/bungee/protocol/Protocol.java

@@ -10,6 +10,7 @@ import java.util.function.Supplier;
 import lombok.Data;
 import lombok.Getter;
 import net.md_5.bungee.protocol.packet.BossBar;
+import net.md_5.bungee.protocol.packet.BundleDelimiter;
 import net.md_5.bungee.protocol.packet.Chat;
 import net.md_5.bungee.protocol.packet.ClearDialog;
 import net.md_5.bungee.protocol.packet.ClearTitles;
@@ -85,6 +86,11 @@ public enum Protocol
     {
 
         {
+            TO_CLIENT.registerPacket(
+                    BundleDelimiter.class,
+                    BundleDelimiter::new,
+                    map( ProtocolConstants.MINECRAFT_1_19_4, 0x00 )
+            );
             TO_CLIENT.registerPacket(
                     KeepAlive.class,
                     KeepAlive::new,

protocol/src/main/java/net/md_5/bungee/protocol/packet/BundleDelimiter.java

@@ -0,0 +1,29 @@
+package net.md_5.bungee.protocol.packet;
+
+import io.netty.buffer.ByteBuf;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import net.md_5.bungee.protocol.AbstractPacketHandler;
+import net.md_5.bungee.protocol.DefinedPacket;
+
+@Data
+@EqualsAndHashCode(callSuper = false)
+public class BundleDelimiter extends DefinedPacket
+{
+
+    @Override
+    public void read(ByteBuf buf)
+    {
+    }
+
+    @Override
+    public void write(ByteBuf buf)
+    {
+    }
+
+    @Override
+    public void handle(AbstractPacketHandler handler) throws Exception
+    {
+        handler.handle( this );
+    }
+}

proxy/src/main/java/net/md_5/bungee/ServerConnector.java

@@ -39,6 +39,7 @@ import net.md_5.bungee.protocol.Either;
 import net.md_5.bungee.protocol.PacketWrapper;
 import net.md_5.bungee.protocol.Protocol;
 import net.md_5.bungee.protocol.ProtocolConstants;
+import net.md_5.bungee.protocol.packet.BundleDelimiter;
 import net.md_5.bungee.protocol.packet.CookieRequest;
 import net.md_5.bungee.protocol.packet.CookieResponse;
 import net.md_5.bungee.protocol.packet.EncryptionRequest;
@@ -369,9 +370,13 @@ public class ServerConnector extends PacketHandler
         {
             if ( user.getServer() != null )
             {
-                // Begin config mode
                 if ( user.getCh().getEncodeProtocol() != Protocol.CONFIGURATION )
                 {
+                    if ( user.isBundling() )
+                    {
+                        user.toggleBundling();
+                        user.unsafe().sendPacket( new BundleDelimiter() );
+                    }
                     user.unsafe().sendPacket( new StartConfiguration() );
                 }
             } else

proxy/src/main/java/net/md_5/bungee/UserConnection.java

@@ -114,6 +114,14 @@ public final class UserConnection implements ProxiedPlayer
     // Used for trying multiple servers in order
     @Setter
     private Queue<String> serverJoinQueue;
+    @Getter
+    @Setter
+    private boolean bundling;
+
+    public void toggleBundling()
+    {
+        bundling = !bundling;
+    }
     /*========================================================================*/
     private final Collection<String> groups = new CaseInsensitiveSet();
     private final Collection<String> permissions = new CaseInsensitiveSet();

proxy/src/main/java/net/md_5/bungee/connection/DownstreamBridge.java

@@ -54,6 +54,7 @@ import net.md_5.bungee.protocol.PacketWrapper;
 import net.md_5.bungee.protocol.Protocol;
 import net.md_5.bungee.protocol.ProtocolConstants;
 import net.md_5.bungee.protocol.packet.BossBar;
+import net.md_5.bungee.protocol.packet.BundleDelimiter;
 import net.md_5.bungee.protocol.packet.Commands;
 import net.md_5.bungee.protocol.packet.FinishConfiguration;
 import net.md_5.bungee.protocol.packet.KeepAlive;
@@ -812,6 +813,12 @@ public class DownstreamBridge extends PacketHandler
         throw CancelSendSignal.INSTANCE;
     }
 
+    @Override
+    public void handle(BundleDelimiter bundleDelimiter) throws Exception
+    {
+        con.toggleBundling();
+    }
+
     @Override
     public String toString()
     {