From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Josh Roy <joshroy126@gmail.com>
Date: Mon, 23 Jan 2023 19:19:01 -0500
Subject: [PATCH] Remove CraftItemStack#setAmount null assignment

This creates a problem with Paper's item serialization
api where deserialized items, which are internally
created as a CraftItemStack, will be completely lost if
#setAmount(0) is invoked (since the underlying handle
is set to null), while a regular Bukkit ItemStack
simply sets the amount field to zero, retaining the
item's data.

Vanilla treats items with zero amounts the same as items
with less than zero amounts, so this code doesn't create
a problem with operations on the vanilla ItemStack.

diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
index 2a7996f5cfb1eacf098e73f35bafc4327b041c51..fa223d2381986cb260c79f074fb7b123396f1f86 100644
--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
@@ -160,7 +160,7 @@ public final class CraftItemStack extends ItemStack {
         }
 
         this.handle.setCount(amount);
-        if (amount == 0) {
+        if (false && amount == 0) { // Paper - remove CraftItemStack#setAmount null assignment
             this.handle = null;
         }
     }