Paper/patches/server/0693-Fix-PlayerBucketEmptyEvent-result-itemstack.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Thu, 20 May 2021 22:16:37 -0700
Subject: [PATCH] Fix PlayerBucketEmptyEvent result itemstack

Fixes SPIGOT-2560: https://hub.spigotmc.org/jira/projects/SPIGOT/issues/SPIGOT-2560

diff --git a/src/main/java/net/minecraft/world/item/BucketItem.java b/src/main/java/net/minecraft/world/item/BucketItem.java
index 650b59b69eb12112bc71e5ff164767e3118e1c2a..69c992ef0c526adf35907de7726832605187beb6 100644
--- a/src/main/java/net/minecraft/world/item/BucketItem.java
+++ b/src/main/java/net/minecraft/world/item/BucketItem.java
@@ -41,6 +41,8 @@ import org.bukkit.event.player.PlayerBucketFillEvent;
 
 public class BucketItem extends Item implements DispensibleContainerItem {
 
+    private static ItemStack itemLeftInHandAfterPlayerBucketEmptyEvent = null; // Paper
+
     public final Fluid content;
 
     public BucketItem(Fluid fluid, Item.Properties settings) {
@@ -122,6 +124,13 @@ public class BucketItem extends Item implements DispensibleContainerItem {
     }
 
     public static ItemStack getEmptySuccessItem(ItemStack stack, Player player) {
+        // Paper start
+        if (itemLeftInHandAfterPlayerBucketEmptyEvent != null) {
+            ItemStack itemInHand = itemLeftInHandAfterPlayerBucketEmptyEvent;
+            itemLeftInHandAfterPlayerBucketEmptyEvent = null;
+            return itemInHand;
+        }
+        // Paper end
         return !player.getAbilities().instabuild ? new ItemStack(Items.BUCKET) : stack;
     }
 
@@ -154,6 +163,9 @@ public class BucketItem extends Item implements DispensibleContainerItem {
                     ((ServerPlayer) entityhuman).getBukkitEntity().updateInventory(); // SPIGOT-4541
                     return false;
                 }
+                // Paper start
+                itemLeftInHandAfterPlayerBucketEmptyEvent = event.getItemStack().equals(CraftItemStack.asNewCraftStack(net.minecraft.world.item.Items.BUCKET)) ? null : CraftItemStack.asNMSCopy(event.getItemStack());
+                // Paper end
             }
             // CraftBukkit end
             if (!flag1) {