From 166dc90e1cc0f370d3e60c5ef76c69543210e685 Mon Sep 17 00:00:00 2001
From: Josh Roy <10731363+JRoy@users.noreply.github.com>
Date: Tue, 24 Jan 2023 09:30:51 -0500
Subject: [PATCH] Remove CraftItemStack#setAmount null assignment (#8807)

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.
---
 .../Add-Raw-Byte-Entity-Serialization.patch   |  5 ++--
 ...Add-Raw-Byte-ItemStack-Serialization.patch |  3 +-
 ...tItemStack-setAmount-null-assignment.patch | 30 +++++++++++++++++++
 3 files changed, 33 insertions(+), 5 deletions(-)
 create mode 100644 patches/server/Remove-CraftItemStack-setAmount-null-assignment.patch

diff --git a/patches/server/Add-Raw-Byte-Entity-Serialization.patch b/patches/server/Add-Raw-Byte-Entity-Serialization.patch
index 70438a6db6..4074e099d1 100644
--- a/patches/server/Add-Raw-Byte-Entity-Serialization.patch
+++ b/patches/server/Add-Raw-Byte-Entity-Serialization.patch
@@ -49,7 +49,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 --- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
 +++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
 @@ -0,0 +0,0 @@ public final class CraftMagicNumbers implements UnsafeValues {
-         return CraftItemStack.asCraftMirror(net.minecraft.world.item.ItemStack.of((CompoundTag) converted.getValue()));
+         return CraftItemStack.asCraftMirror(net.minecraft.world.item.ItemStack.of(ca.spottedleaf.dataconverter.minecraft.MCDataConverter.convertTag(ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry.ITEM_STACK, compound, dataVersion, getDataVersion())));
      }
  
 +    @Override
@@ -69,8 +69,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +
 +        CompoundTag compound = deserializeNbtFromBytes(data);
 +        int dataVersion = compound.getInt("DataVersion");
-+        Dynamic<Tag> converted = DataFixers.getDataFixer().update(References.ENTITY_TREE, new Dynamic<>(NbtOps.INSTANCE, compound), dataVersion, getDataVersion());
-+        compound = (CompoundTag) converted.getValue();
++        compound = ca.spottedleaf.dataconverter.minecraft.MCDataConverter.convertTag(ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry.ENTITY, compound, dataVersion, getDataVersion());
 +        if (!preserveUUID) compound.remove("UUID"); // Generate a new UUID so we don't have to worry about deserializing the same entity twice
 +        return net.minecraft.world.entity.EntityType.create(compound, ((org.bukkit.craftbukkit.CraftWorld) world).getHandle())
 +            .orElseThrow(() -> new IllegalArgumentException("An ID was not found for the data. Did you downgrade?")).getBukkitEntity();
diff --git a/patches/server/Add-Raw-Byte-ItemStack-Serialization.patch b/patches/server/Add-Raw-Byte-ItemStack-Serialization.patch
index d39f4869d4..e02614e295 100644
--- a/patches/server/Add-Raw-Byte-ItemStack-Serialization.patch
+++ b/patches/server/Add-Raw-Byte-ItemStack-Serialization.patch
@@ -29,8 +29,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +
 +        CompoundTag compound = deserializeNbtFromBytes(data);
 +        int dataVersion = compound.getInt("DataVersion");
-+        Dynamic<Tag> converted = DataFixers.getDataFixer().update(References.ITEM_STACK, new Dynamic<Tag>(NbtOps.INSTANCE, compound), dataVersion, getDataVersion());
-+        return CraftItemStack.asCraftMirror(net.minecraft.world.item.ItemStack.of((CompoundTag) converted.getValue()));
++        return CraftItemStack.asCraftMirror(net.minecraft.world.item.ItemStack.of(ca.spottedleaf.dataconverter.minecraft.MCDataConverter.convertTag(ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry.ITEM_STACK, compound, dataVersion, getDataVersion())));
 +    }
 +
 +    private byte[] serializeNbtToBytes(CompoundTag compound) {
diff --git a/patches/server/Remove-CraftItemStack-setAmount-null-assignment.patch b/patches/server/Remove-CraftItemStack-setAmount-null-assignment.patch
new file mode 100644
index 0000000000..6741ed5cda
--- /dev/null
+++ b/patches/server/Remove-CraftItemStack-setAmount-null-assignment.patch
@@ -0,0 +1,30 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Josh Roy <10731363+JRoy@users.noreply.github.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 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
++++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
+@@ -0,0 +0,0 @@ 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;
+         }
+     }