Add option to fix items merging through blocks (#5334)

Fixes #5204

Spigot-Server-Patches/0750-Add-option-to-fix-items-merging-through-walls.patch

@@ -0,0 +1,39 @@
+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 37f866629b7eed39ced4352c94e56c8de8ccfeb9..795b76379eb698aa0ed83c000ea0679a844792d5 100644
+--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
++++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+@@ -820,4 +820,9 @@ 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/EntityItem.java b/src/main/java/net/minecraft/world/entity/item/EntityItem.java
+index 575833807ff647f30d7c2b7abcd01701c7dec85b..8b79220c27292f9b92d9884bbbe4b16d7762343c 100644
+--- a/src/main/java/net/minecraft/world/entity/item/EntityItem.java
++++ b/src/main/java/net/minecraft/world/entity/item/EntityItem.java
+@@ -228,6 +228,14 @@ public class EntityItem extends Entity {
+                 EntityItem entityitem = (EntityItem) iterator.next();
+ 
+                 if (entityitem.z()) {
++                    // Paper Start - Fix items merging through walls
++                        if (this.world.paperConfig.fixItemsMergingThroughWalls) {
++                            net.minecraft.world.level.RayTrace rayTrace = new net.minecraft.world.level.RayTrace(this.getPositionVector(), entityitem.getPositionVector(),
++                                net.minecraft.world.level.RayTrace.BlockCollisionOption.COLLIDER, net.minecraft.world.level.RayTrace.FluidCollisionOption.NONE, this);
++                            net.minecraft.world.phys.MovingObjectPositionBlock rayTraceResult = world.rayTrace(rayTrace);
++                            if (rayTraceResult.getType() == net.minecraft.world.phys.MovingObjectPosition.EnumMovingObjectType.BLOCK) continue;
++                        }
++                    // Paper End
+                     this.a(entityitem);
+                     if (this.dead) {
+                         break;