From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Mariell Hoversholm <proximyst@proximyst.com>
Date: Fri, 14 Aug 2020 23:41:19 +0200
Subject: [PATCH] Don't mark null chunk sections for block updates


diff --git a/src/main/java/net/minecraft/server/level/ChunkHolder.java b/src/main/java/net/minecraft/server/level/ChunkHolder.java
index 1f67c9c5f7161ea687983e7ae0ec7d259da9acd3..32bcc55ce15d832e2182d89acecd715947b1667d 100644
--- a/src/main/java/net/minecraft/server/level/ChunkHolder.java
+++ b/src/main/java/net/minecraft/server/level/ChunkHolder.java
@@ -315,6 +315,7 @@ public class ChunkHolder {
                         this.a(world, blockposition, iblockdata);
                     } else {
                         LevelChunkSection chunksection = chunk.getSections()[j];
+                        if (chunksection == null) chunksection = new LevelChunkSection(sectionposition.getY(), chunk, world, true); // Paper - make a new chunk section if none was found
                         ClientboundSectionBlocksUpdatePacket packetplayoutmultiblockchange = new ClientboundSectionBlocksUpdatePacket(sectionposition, shortset, chunksection, this.resendLight);
 
                         this.broadcast(packetplayoutmultiblockchange, false);