Synced data attachments on players aren't re-sent when they change dimension

[legobmw99]

Minecraft Version: 1.21.8

NeoForge Version: 21.8.11

Steps to Reproduce:

Here's a simple examplemod:

import com.mojang.serialization.Codec;
import net.minecraft.client.Minecraft;
import net.minecraft.network.RegistryFriendlyByteBuf;
import net.neoforged.bus.api.IEventBus;
import net.neoforged.bus.api.SubscribeEvent;
import net.neoforged.fml.common.EventBusSubscriber;
import net.neoforged.fml.common.Mod;
import net.neoforged.neoforge.attachment.AttachmentSyncHandler;
import net.neoforged.neoforge.attachment.AttachmentType;
import net.neoforged.neoforge.attachment.IAttachmentHolder;
import net.neoforged.neoforge.client.event.ClientTickEvent;
import net.neoforged.neoforge.event.entity.player.PlayerEvent;
import net.neoforged.neoforge.registries.DeferredRegister;
import net.neoforged.neoforge.registries.NeoForgeRegistries;
import org.jetbrains.annotations.Nullable;

import java.util.function.Supplier;

@Mod(value = "examplemod")
public class TattleTaleAttachment {

    private static final DeferredRegister<AttachmentType<?>> ATTACHMENT_TYPES =
            DeferredRegister.create(NeoForgeRegistries.ATTACHMENT_TYPES, "examplemod");

    private static final Supplier<AttachmentType<Integer>> TT_ATTACHMENT =

            ATTACHMENT_TYPES.register("tt_attachment", () -> AttachmentType
                    .builder(() -> 0)
                    .serialize(Codec.INT.fieldOf("value"))
                    .sync(new AttachmentSyncHandler<>() {
                        @Override
                        public void write(RegistryFriendlyByteBuf buf, Integer attachment, boolean initialSync) {
                            System.out.println("writing: " + attachment);
                            buf.writeInt(attachment);
                        }

                        @Override
                        public @Nullable Integer read(IAttachmentHolder holder,
                                                      RegistryFriendlyByteBuf buf,
                                                      @Nullable Integer previousValue) {
                            int value = buf.readInt();
                            System.out.println("reading! " + value);
                            return value;
                        }

                    })
                    .copyOnDeath()
                    .build());

    public TattleTaleAttachment(IEventBus bus) {
        ATTACHMENT_TYPES.register(bus);
    }

    @EventBusSubscriber(modid = "examplemod")
    public final class Events {

        @SubscribeEvent
        public static void onJoinWorld(final PlayerEvent.PlayerLoggedInEvent event) {
            event.getEntity().setData(TT_ATTACHMENT, 1);
        }

        @SubscribeEvent
        public static void onClientTick(final ClientTickEvent.Post event) {
            if (Minecraft.getInstance().player != null) {
                System.out.println("Current value: " + Minecraft.getInstance().player.getData(TT_ATTACHMENT));
            }
        }
    }

}

When you log in, this will spam Current value: 1 in the console. Go to the nether, and you'll start seeing Current value: 0. Relog, and it turns back to 1.

Description of issue:

When changing dimension, my attachment is not synced. Before syncing was built in I was subscribing to PlayerEvent.PlayerChangedDimensionEvent and syncing there as well, and I think Neo should as well.

[Technici4n]

Indeed, looks like I forgot a patch in ServerPlayer#teleport (or alternatively a listener to PlayerChangedDimensionEvent).

[neoforged-releases]

🚀 This issue has been resolved in NeoForge version 21.8.20, as part of #2530.