From 7ee711460fae3005542ca198a6d8e1b46daed390 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 25 May 2020 14:19:11 -0400
Subject: [PATCH] Add missing null check for structure start chunk access

Spigot made structure start not load chunks, but forgot to null check
the result...

This likely never blew up before due to the chunk leak issue, but now
that leaky chunks are cleaned up, it was identified.
---
 .../0532-Unload-leaked-Cached-Chunks.patch    | 25 +++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/Spigot-Server-Patches/0532-Unload-leaked-Cached-Chunks.patch b/Spigot-Server-Patches/0532-Unload-leaked-Cached-Chunks.patch
index fb0d8df26..0035a12fc 100644
--- a/Spigot-Server-Patches/0532-Unload-leaked-Cached-Chunks.patch
+++ b/Spigot-Server-Patches/0532-Unload-leaked-Cached-Chunks.patch
@@ -18,10 +18,18 @@ We will now detect these chunks in that iteration, and automatically
 add it to the unload queue when the chunk is found without any tickets.
 
 diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
-index 54e89c9cc6c47ff2c4f4dd5d4c22a391f8a3d6e0..5254e436ce42dd2ab5e0aac5168a9f1f92c9da26 100644
+index 54e89c9cc6c47ff2c4f4dd5d4c22a391f8a3d6e0..59f19c38b06dd3370f9e1604af59535934715abc 100644
 --- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
 +++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
-@@ -898,6 +898,33 @@ public class ChunkProviderServer extends IChunkProvider {
+@@ -560,6 +560,7 @@ public class ChunkProviderServer extends IChunkProvider {
+             }
+         }
+         // Paper start
++        if (playerchunk != null) playerchunk.lastActivity = world.getTime(); // Paper
+         CompletableFuture<Either<IChunkAccess, PlayerChunk.Failure>> future = this.a(playerchunk, l) ? PlayerChunk.UNLOADED_CHUNK_ACCESS_FUTURE : playerchunk.a(chunkstatus, this.playerChunkMap);
+         if (isUrgent) {
+             future.thenAccept(either -> this.chunkMapDistance.clearUrgent(chunkcoordintpair));
+@@ -898,6 +899,33 @@ public class ChunkProviderServer extends IChunkProvider {
                          if (chunksTicked[0]++ % 10 == 0) this.world.getMinecraftServer().midTickLoadChunks(); // Paper
                      }
                  }
@@ -104,3 +112,16 @@ index 2b09437642ec846d025b226692f2290f9bb5b556..b7d8a7487e303c2c44160ec1093987b3
              PlayerChunk playerchunk = (PlayerChunk) this.updatingChunks.remove(j);
  
              if (playerchunk != null) {
+diff --git a/src/main/java/net/minecraft/server/StructureGenerator.java b/src/main/java/net/minecraft/server/StructureGenerator.java
+index acfe732af5b9f63fc2f6b78499defabe2e73ee45..25b19346fc1c702cc37275d0ec16abbbfacfb418 100644
+--- a/src/main/java/net/minecraft/server/StructureGenerator.java
++++ b/src/main/java/net/minecraft/server/StructureGenerator.java
+@@ -160,7 +160,7 @@ public abstract class StructureGenerator<C extends WorldGenFeatureConfiguration>
+         while (longiterator.hasNext()) {
+             long k = longiterator.nextLong();
+             IChunkAccess ichunkaccess1 = generatoraccess.getChunkAt(ChunkCoordIntPair.getX(k), ChunkCoordIntPair.getZ(k), ChunkStatus.STRUCTURE_STARTS, false); // CraftBukkit - don't load chunks
+-            StructureStart structurestart = ichunkaccess1.a(this.b());
++            StructureStart structurestart = ichunkaccess1 != null ? ichunkaccess1.a(this.b()) : null; // Paper - make sure not null
+ 
+             if (structurestart != null) {
+                 list.add(structurestart);