Bulk bugfixes for itemstack damage API (#11063)

A general set of bugfixes for itemstack damage related logic.

1. Prevent NPE when calling deprecated ItemStack#getMaxItemUseDuration()
2. Do not apply enchantments when damaging items via API
3. Do not error when passing a null equipment slot to hurtAndBreak
4. Correctly call PlayerItemBreakEvent

1 files changed, 34 insertions, 0 deletions

diff --git a/patches/server/1040-Correctly-call-PlayerItemBreakEvent.patch b/patches/server/1040-Correctly-call-PlayerItemBreakEvent.patch
new file mode 100644
index 0000000000..6637cd6cd0
--- /dev/null
+++ b/patches/server/1040-Correctly-call-PlayerItemBreakEvent.patch
@@ -0,0 +1,34 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Bjarne Koll <[email protected]>
+Date: Fri, 12 Jul 2024 19:09:44 +0200
+Subject: [PATCH] Correctly call PlayerItemBreakEvent
+
+The minecraft 1.21 update changed the invocation order in
+ItemStack#hurtAndBreak, now first shrinking the itemstack to a count of
+zero and then invoking the break callback.
+
+This leads to spigots logic no longer firing at all. This patch now
+correctly executes on count of zero and temporarily bumps the count to
+one before passing it to event handlers to maintain compatibility with
+the event contracts.
+
+This fix was chosen over invoking the callback prior to shrinking the
+stack to not disrupt potential new vanilla changes that might depend on
+this behaviour.
+
+diff --git a/src/main/java/net/minecraft/world/item/ItemStack.java b/src/main/java/net/minecraft/world/item/ItemStack.java
+index 0f2b3c5ca88478a541bf9e61ae61cc99a7d08836..2c312c0b741fb96a008881e9e01fa660a1fb63ab 100644
+--- a/src/main/java/net/minecraft/world/item/ItemStack.java
++++ b/src/main/java/net/minecraft/world/item/ItemStack.java
+@@ -731,8 +731,10 @@ public final class ItemStack implements DataComponentHolder {
+ 
+             this.hurtAndBreak(amount, worldserver, entity, (item) -> { // Paper - Add EntityDamageItemEvent
+                 // CraftBukkit start - Check for item breaking
+-                if (this.count == 1 && entity instanceof net.minecraft.world.entity.player.Player) {
++                if (this.count == 0 && entity instanceof net.minecraft.world.entity.player.Player) { // Paper - correctly call item break event - run if count reached 0
++                    this.setCount(1); // Paper - correctly call item break event - grow to count 1
+                     org.bukkit.craftbukkit.event.CraftEventFactory.callPlayerItemBreakEvent((net.minecraft.world.entity.player.Player) entity, this);
++                    this.setCount(0); // Paper - correctly call item break event - reset to count 0
+                 }
+                 // CraftBukkit end
+                 if (slot != null) entity.onEquippedItemBroken(item, slot); // Paper - itemstack damage API - do not process entity related callbacks when damaging from API