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 eff5a39968c8a4ff49ca9a7de5e2bf2a20ea7fd8..0059c837ab3b1223c56aa9fbc96dd2aedd13e0eb 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -833,4 +833,9 @@ 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 995172d8f271520ffa09e919f2a4890a4a1ccd89..0a1ef65c7199939035f2d548525b72bd0e40704d 100644
--- a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
@@ -240,6 +240,14 @@ 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;