How to craft a bundled packet

[josemmo]

Hi!

I'm trying to take advantage of the new bundled packets from 1.19.4 and I'm having trouble getting it to work.

Here's the code I'm using to send a bundle packet container:

ProtocolManager connection = ProtocolLibrary.getProtocolManager();
List<PacketContainer> packets = new ArrayList<>();
// [...]

PacketContainer container = new PacketContainer(PacketType.Play.Server.BUNDLE);
container.getPacketBundles().write(0, packets); // <--- This line throws the exception
connection.sendServerPacket(player, container);

However, this code throws the following exception:

java.lang.IllegalStateException: Unable to set value of field private final java.lang.Iterable net.minecraft.network.protocol.BundlePacket.a
       at ProtocolLib-5.0.0-SNAPSHOT-b636.jar//com.comphenix.protocol.reflect.accessors.DefaultFieldAccessor.set(DefaultFieldAccessor.java:44)
       at ProtocolLib-5.0.0-SNAPSHOT-b636.jar//com.comphenix.protocol.reflect.StructureModifier.writeInternal(StructureModifier.java:359)
       at ProtocolLib-5.0.0-SNAPSHOT-b636.jar//com.comphenix.protocol.reflect.StructureModifier.write(StructureModifier.java:322)
       at YamipaPlugin.jar//io.josemmo.bukkit.plugin.renderer.FakeEntity.tryToSendPackets(FakeEntity.java:114)
       at YamipaPlugin.jar//io.josemmo.bukkit.plugin.renderer.FakeImage.destroy(FakeImage.java:478)
       at YamipaPlugin.jar//io.josemmo.bukkit.plugin.renderer.FakeImage.destroy(FakeImage.java:454)
       at YamipaPlugin.jar//io.josemmo.bukkit.plugin.renderer.ImageRenderer.stop(ImageRenderer.java:64)
       at YamipaPlugin.jar//io.josemmo.bukkit.plugin.YamipaPlugin.onDisable(YamipaPlugin.java:136)
       at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:281)
       at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.disablePlugin(PaperPluginInstanceManager.java:227)
       at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.disablePlugins(PaperPluginInstanceManager.java:151)
       at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.disablePlugins(PaperPluginManagerImpl.java:92)
       at org.bukkit.plugin.SimplePluginManager.disablePlugins(SimplePluginManager.java:528)
       at org.bukkit.craftbukkit.v1_19_R3.CraftServer.disablePlugins(CraftServer.java:486)
       at net.minecraft.server.MinecraftServer.t(MinecraftServer.java:947)
       at net.minecraft.server.dedicated.DedicatedServer.t(DedicatedServer.java:804)
       at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:1213)
       at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:320)
       at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.ClassCastException: Cannot cast net.minecraft.network.protocol.BundleDelimiterPacket to net.minecraft.network.protocol.BundlePacket
       at java.base/java.lang.Class.cast(Class.java:3889)
       at ProtocolLib-5.0.0-SNAPSHOT-b636.jar//com.comphenix.protocol.reflect.accessors.DefaultFieldAccessor.set(DefaultFieldAccessor.java:41)
       ... 18 more

Anyone knows what's the intended way of constructing a PacketType.Play.Server.BUNDLE packet container?

[lukalt]

The way you are writing the bundle seems to be correct. I would consider this as a bug.
The problem is that the Bundle is just a virtual packet and somehow is not created correctly internally.

[josemmo]

Thanks for the response! I'll create an issue, then.