From 7ab0c41be6fcf0c3cea0231a20a46973975bedf8 Mon Sep 17 00:00:00 2001
From: Nassim Jahnke <jahnke.nassim@gmail.com>
Date: Wed, 8 Jun 2022 10:07:47 +0200
Subject: [PATCH] Fix villager trade offers Fixes #2919

---
 .../viaversion/viaversion/BungeePlugin.java   |  2 +-
 .../packets/InventoryPackets.java             | 30 ++++++++++++++++++-
 .../viaversion/rewriter/ItemRewriter.java     | 26 ++++++++++++++++
 3 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/bungee/src/main/java/com/viaversion/viaversion/BungeePlugin.java b/bungee/src/main/java/com/viaversion/viaversion/BungeePlugin.java
index 11e7dcce1..badb52042 100644
--- a/bungee/src/main/java/com/viaversion/viaversion/BungeePlugin.java
+++ b/bungee/src/main/java/com/viaversion/viaversion/BungeePlugin.java
@@ -56,7 +56,7 @@ public class BungeePlugin extends Plugin implements ViaPlatform<ProxiedPlayer>,
     @Override
     public void onLoad() {
         try {
-            ProtocolConstants.class.getField("MINECRAFT_1_18");
+            ProtocolConstants.class.getField("MINECRAFT_1_19");
         } catch (NoSuchFieldException e) {
             getLogger().warning("      / \\");
             getLogger().warning("     /   \\");
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_19to1_18_2/packets/InventoryPackets.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_19to1_18_2/packets/InventoryPackets.java
index f8aea24f5..c8abce709 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_19to1_18_2/packets/InventoryPackets.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_19to1_18_2/packets/InventoryPackets.java
@@ -38,7 +38,6 @@ public final class InventoryPackets extends ItemRewriter<Protocol1_19To1_18_2> {
     public void registerPackets() {
         registerSetCooldown(ClientboundPackets1_18.COOLDOWN);
         registerWindowItems1_17_1(ClientboundPackets1_18.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY_VAR_INT, Type.FLAT_VAR_INT_ITEM);
-        registerTradeList(ClientboundPackets1_18.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
         registerSetSlot1_17_1(ClientboundPackets1_18.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
         registerAdvancements(ClientboundPackets1_18.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
         registerEntityEquipmentArray(ClientboundPackets1_18.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
@@ -64,6 +63,35 @@ public final class InventoryPackets extends ItemRewriter<Protocol1_19To1_18_2> {
 
         registerWindowPropertyEnchantmentHandler(ClientboundPackets1_18.WINDOW_PROPERTY);
 
+        protocol.registerClientbound(ClientboundPackets1_18.TRADE_LIST, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                map(Type.VAR_INT); // Container id
+                handler(wrapper -> {
+                    final int size = wrapper.read(Type.UNSIGNED_BYTE);
+                    wrapper.write(Type.VAR_INT, size);
+                    for (int i = 0; i < size; i++) {
+                        handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // First item
+                        handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
+
+                        if (wrapper.read(Type.BOOLEAN)) {
+                            handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
+                        } else {
+                            wrapper.write(Type.FLAT_VAR_INT_ITEM, null);
+                        }
+
+                        wrapper.passthrough(Type.BOOLEAN); // Out of stock
+                        wrapper.passthrough(Type.INT); // Uses
+                        wrapper.passthrough(Type.INT); // Max uses
+                        wrapper.passthrough(Type.INT); // Xp
+                        wrapper.passthrough(Type.INT); // Special price diff
+                        wrapper.passthrough(Type.FLOAT); // Price multiplier
+                        wrapper.passthrough(Type.INT); //Demand
+                    }
+                });
+            }
+        });
+
         protocol.registerServerbound(ServerboundPackets1_19.PLAYER_DIGGING, new PacketRemapper() {
             @Override
             public void registerMap() {
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 54faaf15e..90bce2191 100644
--- a/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
+++ b/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
@@ -240,6 +240,32 @@ public abstract class ItemRewriter<T extends Protocol> extends RewriterBase<T> i
         });
     }
 
+    public void registerTradeList1_19(ClientboundPacketType packetType, Type<Item> type) {
+        protocol.registerClientbound(packetType, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                handler(wrapper -> {
+                    wrapper.passthrough(Type.VAR_INT); // Container id
+                    int size = wrapper.passthrough(Type.VAR_INT);
+                    for (int i = 0; i < size; i++) {
+                        handleItemToClient(wrapper.passthrough(type)); // Input
+                        handleItemToClient(wrapper.passthrough(type)); // Output
+                        handleItemToClient(wrapper.passthrough(type)); // Second Item
+
+                        wrapper.passthrough(Type.BOOLEAN); // Trade disabled
+                        wrapper.passthrough(Type.INT); // Number of tools uses
+                        wrapper.passthrough(Type.INT); // Maximum number of trade uses
+
+                        wrapper.passthrough(Type.INT); // XP
+                        wrapper.passthrough(Type.INT); // Special price
+                        wrapper.passthrough(Type.FLOAT); // Price multiplier
+                        wrapper.passthrough(Type.INT); // Demand
+                    }
+                });
+            }
+        });
+    }
+
     public void registerAdvancements(ClientboundPacketType packetType, Type<Item> type) {
         protocol.registerClientbound(packetType, new PacketRemapper() {
             @Override