Paper/patches/server/0748-EntityPickupItemEvent-fixes.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Mon, 4 Jul 2022 21:45:36 -0700
Subject: [PATCH] EntityPickupItemEvent fixes

Fixes double firing of the event in PiglinAi

Fixes cancelling the event for piglins still triggering the
advancement trigger

Fires the event when a Raider tries to pick up a raid banner
to become raid leader.

diff --git a/src/main/java/net/minecraft/world/entity/monster/piglin/Piglin.java b/src/main/java/net/minecraft/world/entity/monster/piglin/Piglin.java
index d2dfa49e124460f4762b950f9ded106d2ec15dc2..bc58323801ee16fe9b63c21332144ec002a902f2 100644
--- a/src/main/java/net/minecraft/world/entity/monster/piglin/Piglin.java
+++ b/src/main/java/net/minecraft/world/entity/monster/piglin/Piglin.java
@@ -412,7 +412,7 @@ public class Piglin extends AbstractPiglin implements CrossbowAttackMob, Invento
 
     @Override
     protected void pickUpItem(ItemEntity item) {
-        this.onItemPickup(item);
+        // this.onItemPickup(item); // Paper - EntityPickupItemEvent fixes; call in PiglinAi#pickUpItem after EntityPickupItemEvent is fired
         PiglinAi.pickUpItem(this, item);
     }
 
diff --git a/src/main/java/net/minecraft/world/entity/monster/piglin/PiglinAi.java b/src/main/java/net/minecraft/world/entity/monster/piglin/PiglinAi.java
index d3d50ec0f4466464c048449d8a844569c447d59b..b9810a1f6ac91ae9631dd1ebc225f009d91b7845 100644
--- a/src/main/java/net/minecraft/world/entity/monster/piglin/PiglinAi.java
+++ b/src/main/java/net/minecraft/world/entity/monster/piglin/PiglinAi.java
@@ -242,11 +242,16 @@ public class PiglinAi {
         ItemStack itemstack;
 
         // CraftBukkit start
-        if (drop.getItem().is(Items.GOLD_NUGGET) && !org.bukkit.craftbukkit.event.CraftEventFactory.callEntityPickupItemEvent(piglin, drop, 0, false).isCancelled()) {
+        // Paper start - EntityPickupItemEvent fixes; fix event firing twice
+        if (drop.getItem().is(Items.GOLD_NUGGET) /* && !org.bukkit.craftbukkit.event.CraftEventFactory.callEntityPickupItemEvent(piglin, drop, 0, false).isCancelled() */) {
+            if (org.bukkit.craftbukkit.event.CraftEventFactory.callEntityPickupItemEvent(piglin, drop, 0, false).isCancelled()) return;
+            piglin.onItemPickup(drop); // Paper - moved from Piglin#pickUpItem - call prior to item entity modification
+            // Paper end - EntityPickupItemEvent fixes
             piglin.take(drop, drop.getItem().getCount());
             itemstack = drop.getItem();
             drop.discard(EntityRemoveEvent.Cause.PICKUP); // CraftBukkit - add Bukkit remove cause
         } else if (!org.bukkit.craftbukkit.event.CraftEventFactory.callEntityPickupItemEvent(piglin, drop, drop.getItem().getCount() - 1, false).isCancelled()) {
+            piglin.onItemPickup(drop); // Paper - EntityPickupItemEvent fixes; moved from Piglin#pickUpItem - call prior to item entity modification
             piglin.take(drop, 1);
             itemstack = PiglinAi.removeOneItemFromItemEntity(drop);
         } else {
@@ -261,7 +266,7 @@ public class PiglinAi {
         } else if (PiglinAi.isFood(itemstack) && !PiglinAi.hasEatenRecently(piglin)) {
             PiglinAi.eat(piglin);
         } else {
-            boolean flag = !piglin.equipItemIfPossible(itemstack, drop).equals(ItemStack.EMPTY); // CraftBukkit
+            boolean flag = !piglin.equipItemIfPossible(itemstack, null).equals(ItemStack.EMPTY); // CraftBukkit // Paper - pass null item entity to prevent duplicate pickup item event call - called above.
 
             if (!flag) {
                 PiglinAi.putInInventory(piglin, itemstack);
diff --git a/src/main/java/net/minecraft/world/entity/raid/Raider.java b/src/main/java/net/minecraft/world/entity/raid/Raider.java
index 174d246b0a4d0fc9d769aad08da627ca8487bdf2..bbf21ea433f9e3963aac0ede597ed8d3c8e50ed8 100644
--- a/src/main/java/net/minecraft/world/entity/raid/Raider.java
+++ b/src/main/java/net/minecraft/world/entity/raid/Raider.java
@@ -225,6 +225,11 @@ public abstract class Raider extends PatrollingMonster {
         boolean flag = this.hasActiveRaid() && this.getCurrentRaid().getLeader(this.getWave()) != null;
 
         if (this.hasActiveRaid() && !flag && ItemStack.matches(itemstack, Raid.getLeaderBannerInstance(this.registryAccess().lookupOrThrow(Registries.BANNER_PATTERN)))) {
+            // Paper start - EntityPickupItemEvent fixes
+            if (org.bukkit.craftbukkit.event.CraftEventFactory.callEntityPickupItemEvent(this, item, 0, false).isCancelled()) {
+                return;
+            }
+            // Paper end - EntityPickupItemEvent fixes
             EquipmentSlot enumitemslot = EquipmentSlot.HEAD;
             ItemStack itemstack1 = this.getItemBySlot(enumitemslot);
             double d0 = (double) this.getEquipmentDropChance(enumitemslot);