From 750b270502f3cfed746099bd04988557f9f4ccf7 Mon Sep 17 00:00:00 2001
From: Kelsi <kelsihates2fa@gmail.com>
Date: Wed, 11 Mar 2026 04:01:07 -0700
Subject: [PATCH] fix: use expansion-aware item size in LootResponseParser for
 Classic/TBC
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The previous per-iteration heuristic (remaining >= 22 → 22 bytes, >= 14 → 14 bytes)
incorrectly parsed Classic/TBC multi-item loots: 2+ items × 14 bytes would
trigger the 22-byte WotLK path for the first item, corrupting subsequent items.

Classic 1.12 and TBC 2.4.3 use 14 bytes/item (slot+itemId+count+displayInfo+slotType).
WotLK 3.3.5a uses 22 bytes/item (adds randomSuffix+randomPropertyId).

Add isWotlkFormat bool parameter to LootResponseParser::parse and pass
isActiveExpansion('wotlk') from handleLootResponse.
---
 include/game/world_packets.hpp |  4 +++-
 src/game/game_handler.cpp      |  5 ++++-
 src/game/world_packets.cpp     | 41 +++++++++++++---------------------
 3 files changed, 22 insertions(+), 28 deletions(-)

diff --git a/include/game/world_packets.hpp b/include/game/world_packets.hpp
index 61d36ebf..539d3b8a 100644
--- a/include/game/world_packets.hpp
+++ b/include/game/world_packets.hpp
@@ -2015,7 +2015,9 @@ public:
 /** SMSG_LOOT_RESPONSE parser */
 class LootResponseParser {
 public:
-    static bool parse(network::Packet& packet, LootResponseData& data);
+    // isWotlkFormat: true for WotLK 3.3.5a (22 bytes/item with randomSuffix+randomProp),
+    //                false for Classic 1.12 and TBC 2.4.3 (14 bytes/item).
+    static bool parse(network::Packet& packet, LootResponseData& data, bool isWotlkFormat = true);
 };
 
 // ============================================================
diff --git a/src/game/game_handler.cpp b/src/game/game_handler.cpp
index bce39d4a..f7f42b59 100644
--- a/src/game/game_handler.cpp
+++ b/src/game/game_handler.cpp
@@ -16164,7 +16164,10 @@ void GameHandler::unstuckHearth() {
 }
 
 void GameHandler::handleLootResponse(network::Packet& packet) {
-    if (!LootResponseParser::parse(packet, currentLoot)) return;
+    // Classic 1.12 and TBC 2.4.3 use 14 bytes/item (no randomSuffix/randomProp fields);
+    // WotLK 3.3.5a uses 22 bytes/item.
+    const bool wotlkLoot = isActiveExpansion("wotlk");
+    if (!LootResponseParser::parse(packet, currentLoot, wotlkLoot)) return;
     lootWindowOpen = true;
     localLootState_[currentLoot.lootGuid] = LocalLootState{currentLoot, false};
 
diff --git a/src/game/world_packets.cpp b/src/game/world_packets.cpp
index 545f2f70..8c7c5ec9 100644
--- a/src/game/world_packets.cpp
+++ b/src/game/world_packets.cpp
@@ -3320,7 +3320,7 @@ network::Packet LootReleasePacket::build(uint64_t lootGuid) {
     return packet;
 }
 
-bool LootResponseParser::parse(network::Packet& packet, LootResponseData& data) {
+bool LootResponseParser::parse(network::Packet& packet, LootResponseData& data, bool isWotlkFormat) {
     data = LootResponseData{};
     if (packet.getSize() - packet.getReadPos() < 14) {
         LOG_WARNING("LootResponseParser: packet too short");
@@ -3332,45 +3332,34 @@ bool LootResponseParser::parse(network::Packet& packet, LootResponseData& data)
     data.gold = packet.readUInt32();
     uint8_t itemCount = packet.readUInt8();
 
+    // Item wire size:
+    //   WotLK 3.3.5a: slot(1)+itemId(4)+count(4)+displayInfo(4)+randSuffix(4)+randProp(4)+slotType(1) = 22
+    //   Classic/TBC:  slot(1)+itemId(4)+count(4)+displayInfo(4)+slotType(1)                          = 14
+    const size_t kItemSize = isWotlkFormat ? 22u : 14u;
+
     auto parseLootItemList = [&](uint8_t listCount, bool markQuestItems) -> bool {
         for (uint8_t i = 0; i < listCount; ++i) {
             size_t remaining = packet.getSize() - packet.getReadPos();
-            if (remaining < 10) {
+            if (remaining < kItemSize) {
                 return false;
             }
 
-            // Prefer the richest format when possible:
-            // 22-byte (WotLK/full): slot+id+count+display+randSuffix+randProp+slotType
-            // 14-byte (compact):    slot+id+count+display+slotType
-            // 10-byte (minimal):    slot+id+count+slotType
-            uint8_t bytesPerItem = 10;
-            if (remaining >= 22) {
-                bytesPerItem = 22;
-            } else if (remaining >= 14) {
-                bytesPerItem = 14;
-            }
-
             LootItem item;
-            item.slotIndex = packet.readUInt8();
-            item.itemId = packet.readUInt32();
-            item.count = packet.readUInt32();
+            item.slotIndex     = packet.readUInt8();
+            item.itemId        = packet.readUInt32();
+            item.count         = packet.readUInt32();
+            item.displayInfoId = packet.readUInt32();
 
-            if (bytesPerItem >= 14) {
-                item.displayInfoId = packet.readUInt32();
-            } else {
-                item.displayInfoId = 0;
-            }
-
-            if (bytesPerItem == 22) {
-                item.randomSuffix = packet.readUInt32();
+            if (isWotlkFormat) {
+                item.randomSuffix     = packet.readUInt32();
                 item.randomPropertyId = packet.readUInt32();
             } else {
-                item.randomSuffix = 0;
+                item.randomSuffix     = 0;
                 item.randomPropertyId = 0;
             }
 
             item.lootSlotType = packet.readUInt8();
-            item.isQuestItem = markQuestItems;
+            item.isQuestItem  = markQuestItems;
             data.items.push_back(item);
         }
         return true;