From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 6 May 2020 05:00:57 -0400
Subject: [PATCH] Handle Oversized Tile Entities in chunks

Splits out Extra Packets if too many TE's are encountered to prevent
creating too large of a packet to sed.

Co authored by Spottedleaf

diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java
index b7d303b5f51a35504888933efef74564fa01e59d..b587f774c8f88f2a1c3ea489f7e4fe0bbdeb5a41 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacket.java
@@ -34,7 +34,15 @@ public class ClientboundLevelChunkPacket implements Packet<ClientGamePacketListe
     private boolean fullChunk;
 
     public ClientboundLevelChunkPacket() {}
+    // Paper start
+    private final java.util.List<Packet> extraPackets = new java.util.ArrayList<>();
+    private static final int TE_LIMIT = Integer.getInteger("Paper.excessiveTELimit", 750);
 
+    @Override
+    public java.util.List<Packet> getExtraPackets() {
+        return extraPackets;
+    }
+    // Paper end
     public ClientboundLevelChunkPacket(LevelChunk chunk, int includedSectionsMask) {
         ChunkPos chunkcoordintpair = chunk.getPos();
 
@@ -61,6 +69,7 @@ public class ClientboundLevelChunkPacket implements Packet<ClientGamePacketListe
         this.availableSections = this.extractChunkData(new FriendlyByteBuf(this.getWriteBuffer()), chunk, includedSectionsMask);
         this.blockEntitiesTags = Lists.newArrayList();
         iterator = chunk.getBlockEntities().entrySet().iterator();
+        int totalTileEntities = 0; // Paper
 
         while (iterator.hasNext()) {
             entry = (Entry) iterator.next();
@@ -69,6 +78,15 @@ public class ClientboundLevelChunkPacket implements Packet<ClientGamePacketListe
             int j = blockposition.getY() >> 4;
 
             if (this.isFullChunk() || (includedSectionsMask & 1 << j) != 0) {
+                // Paper start - improve oversized chunk data packet handling
+                if (++totalTileEntities > TE_LIMIT) {
+                    ClientboundBlockEntityDataPacket updatePacket = tileentity.getUpdatePacket();
+                    if (updatePacket != null) {
+                        this.extraPackets.add(updatePacket);
+                        continue;
+                    }
+                }
+                // Paper end
                 CompoundTag nbttagcompound = tileentity.getUpdateTag();
                 if (tileentity instanceof SkullBlockEntity) { SkullBlockEntity.sanitizeTileEntityUUID(nbttagcompound); } // Paper