From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Legitimoose <legitimoose@gmail.com>
Date: Wed, 28 Sep 2022 22:45:49 -0700
Subject: [PATCH] fix Jigsaw block kicking user


diff --git a/src/main/java/net/minecraft/world/level/block/entity/JigsawBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/JigsawBlockEntity.java
index 0083602f8c8826e247fecbdb5cdb6548ff6180ce..675f6b2932e036d2eedf065fd2db4bf9f0e4250d 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/JigsawBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/JigsawBlockEntity.java
@@ -137,7 +137,12 @@ public class JigsawBlockEntity extends BlockEntity {
     public void generate(ServerLevel world, int maxDepth, boolean keepJigsaws) {
         BlockPos blockPos = this.getBlockPos().relative(this.getBlockState().getValue(JigsawBlock.ORIENTATION).front());
         Registry<StructureTemplatePool> registry = world.registryAccess().registryOrThrow(Registries.TEMPLATE_POOL);
-        Holder<StructureTemplatePool> holder = registry.getHolderOrThrow(this.pool);
+        // Paper start - Replace getHolderOrThrow with a null check
+        Holder<StructureTemplatePool> holder = registry.getHolder(this.pool).orElse(null);
+        if (holder == null) {
+            return;
+        }
+        // Paper end - Replace getHolderOrThrow with a null check
         JigsawPlacement.generateJigsaw(world, holder, this.target, maxDepth, blockPos, keepJigsaws);
     }