From 1e244a126dc4d240eea58d2155b34970f00fdf21 Mon Sep 17 00:00:00 2001
From: Nassim Jahnke <nassim@njahnke.dev>
Date: Fri, 7 Jun 2024 13:51:28 +0200
Subject: [PATCH] Handle optional item cost nullability

---
 .../rewriter/BlockItemPacketRewriter1_20_5.java           | 8 +++++++-
 .../com/viaversion/viaversion/rewriter/ItemRewriter.java  | 7 +++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java
index b26e360b6..2c37b7de5 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java
@@ -307,7 +307,13 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
                 final Item output = handleNonEmptyItemToClient(wrapper.user(), wrapper.read(Types.ITEM1_20_2));
                 wrapper.write(Types1_20_5.ITEM, output);
 
-                final Item secondInput = handleItemToClient(wrapper.user(), wrapper.read(Types.ITEM1_20_2));
+                Item secondInput = wrapper.read(Types.ITEM1_20_2);
+                if (secondInput != null) {
+                    secondInput = handleItemToClient(wrapper.user(), secondInput);
+                    if (secondInput.isEmpty()) {
+                        secondInput = null;
+                    }
+                }
                 wrapper.write(Types1_20_5.OPTIONAL_ITEM_COST, secondInput);
 
                 wrapper.passthrough(Types.BOOLEAN); // Out of stock
diff --git a/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java b/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
index f770f39da..80003cdf2 100644
--- a/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
+++ b/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
@@ -296,8 +296,11 @@ public class ItemRewriter<C extends ClientboundPacketType, S extends Serverbound
 
                 handleClientboundItem(wrapper); // Result
 
-                final Item secondInput = wrapper.read(optionalCostType);
-                wrapper.write(mappedOptionalCostType, handleItemToClient(wrapper.user(), secondInput));
+                Item secondInput = wrapper.read(optionalCostType);
+                if (secondInput != null) {
+                    handleItemToClient(wrapper.user(), secondInput);
+                }
+                wrapper.write(mappedOptionalCostType, secondInput);
 
                 wrapper.passthrough(Types.BOOLEAN); // Out of stock
                 wrapper.passthrough(Types.INT); // Number of trade uses