From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: GioSDA <gsdambrosio@gmail.com>
Date: Wed, 10 Mar 2021 10:06:45 -0800
Subject: [PATCH] Add option to fix items merging through walls


diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 604100365cf396165651b1731574938598507ed3..c6b7133a5ac742e402f617acbf4ba351539123d1 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -799,5 +799,10 @@ public class PaperWorldConfig {
     private void mapItemFrameCursorLimit() {
         mapItemFrameCursorLimit = getInt("map-item-frame-cursor-limit", mapItemFrameCursorLimit);
     }
+
+    public boolean fixItemsMergingThroughWalls;
+    private void fixItemsMergingThroughWalls() {
+        fixItemsMergingThroughWalls = getBoolean("fix-items-merging-through-walls", fixItemsMergingThroughWalls);
+    }
 }
 
diff --git a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
index e0c13a112c95eed9867d4608e18dc797b0c9c9cf..158719d46c96bb733a00e08c8285f41a48406abf 100644
--- a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
@@ -241,6 +241,14 @@ public class ItemEntity extends Entity {
                 ItemEntity entityitem = (ItemEntity) iterator.next();
 
                 if (entityitem.isMergable()) {
+                    // Paper Start - Fix items merging through walls
+                        if (this.level.paperConfig.fixItemsMergingThroughWalls) {
+                            net.minecraft.world.level.ClipContext rayTrace = new net.minecraft.world.level.ClipContext(this.position(), entityitem.position(),
+                                net.minecraft.world.level.ClipContext.Block.COLLIDER, net.minecraft.world.level.ClipContext.Fluid.NONE, this);
+                            net.minecraft.world.phys.BlockHitResult rayTraceResult = level.clip(rayTrace);
+                            if (rayTraceResult.getType() == net.minecraft.world.phys.HitResult.Type.BLOCK) continue;
+                        }
+                    // Paper End
                     this.tryToMerge(entityitem);
                     if (this.isRemoved()) {
                         break;