PaperMC/Spigot-Server-Patches/0543-Don-t-mark-null-chunk-sections-for-block-updates.patch

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/PlayerChunk.java b/src/main/java/net/minecraft/server/level/PlayerChunk.java
index d6a5a0b17308913a5efd97cd27fabd0825ef68c6..00cebd33101916f29bbc192d531ac0fba31e037b 100644
--- a/src/main/java/net/minecraft/server/level/PlayerChunk.java
+++ b/src/main/java/net/minecraft/server/level/PlayerChunk.java
@@ -450,6 +450,7 @@ public class PlayerChunk {
                         this.a(world, blockposition, iblockdata);
                     } else {
                         ChunkSection chunksection = chunk.getSections()[sectionposition.getY()];
+                        if (chunksection == null) chunksection = new ChunkSection(sectionposition.getY(), chunk, world, true); // Paper - make a new chunk section if none was found
                         PacketPlayOutMultiBlockChange packetplayoutmultiblockchange = new PacketPlayOutMultiBlockChange(sectionposition, shortset, chunksection, this.x);
 
                         this.a(packetplayoutmultiblockchange, false);