Fix quest system for Classic/Turtle: correct packet formats and log stride

- CMSG_QUESTGIVER_QUERY_QUEST: Classic override omits trailing unk1 byte
  (WotLK sends 13 bytes, Classic servers expect 12 — extra byte caused
  server to silently drop the packet, preventing quest details dialog)
- SMSG_QUESTGIVER_QUEST_DETAILS: Classic override skips informUnit GUID
  (WotLK prepends 8-byte informUnit before questId; Vanilla does not)
- Quest log UPDATE_OBJECT stride: use packetParsers_->questLogStride()
  (WotLK=5 fields/slot, Classic=3 fields/slot)
- handleQuestDetails: route through packetParsers_->parseQuestDetails()
- selectGossipQuest: route through packetParsers_->buildQueryQuestPacket()

include/game/packet_parsers.hpp

@@ -148,6 +148,24 @@ public:
         return GossipMessageParser::parse(packet, data);
     }
 
+    // --- Quest details ---
+
+    /** Build CMSG_QUESTGIVER_QUERY_QUEST.
+     *  WotLK appends a trailing unk1 byte; Vanilla/Classic do not. */
+    virtual network::Packet buildQueryQuestPacket(uint64_t npcGuid, uint32_t questId) {
+        return QuestgiverQueryQuestPacket::build(npcGuid, questId);  // includes unk1
+    }
+
+    /** Parse SMSG_QUESTGIVER_QUEST_DETAILS.
+     *  WotLK has an extra informUnit GUID before questId; Vanilla/Classic do not. */
+    virtual bool parseQuestDetails(network::Packet& packet, QuestDetailsData& data) {
+        return QuestDetailsParser::parse(packet, data);  // WotLK auto-detect
+    }
+
+    /** Stride of PLAYER_QUEST_LOG fields in update-object blocks.
+     *  WotLK: 5 fields per slot, Classic/Vanilla: 3. */
+    virtual uint8_t questLogStride() const { return 5; }
+
     // --- Quest Giver Status ---
 
     /** Read quest giver status from packet.
@@ -304,6 +322,9 @@ public:
     network::Packet buildItemQuery(uint32_t entry, uint64_t guid) override;
     bool parseItemQueryResponse(network::Packet& packet, ItemQueryResponseData& data) override;
     uint8_t readQuestGiverStatus(network::Packet& packet) override;
+    network::Packet buildQueryQuestPacket(uint64_t npcGuid, uint32_t questId) override;
+    bool parseQuestDetails(network::Packet& packet, QuestDetailsData& data) override;
+    uint8_t questLogStride() const override { return 3; }
 };
 
 /**

src/game/game_handler.cpp

@@ -3858,7 +3858,8 @@ void GameHandler::handleUpdateObject(network::Packet& packet) {
                     const uint16_t ufPlayerLevel = fieldIndex(UF::UNIT_FIELD_LEVEL);
                     const uint16_t ufCoinage = fieldIndex(UF::PLAYER_FIELD_COINAGE);
                     const uint16_t ufQuestStart = fieldIndex(UF::PLAYER_QUEST_LOG_START);
-                    const uint16_t ufQuestEnd = ufQuestStart + 25 * 5; // 25 quest slots, stride 5
+                    const uint8_t qStride = packetParsers_ ? packetParsers_->questLogStride() : 5;
+                    const uint16_t ufQuestEnd = ufQuestStart + 25 * qStride; // 25 quest slots
                     for (const auto& [key, val] : block.fields) {
                         if (key == ufPlayerXp) { playerXp_ = val; }
                         else if (key == ufPlayerNextXp) { playerNextLevelXp_ = val; }
@@ -3872,8 +3873,8 @@ void GameHandler::handleUpdateObject(network::Packet& packet) {
                             playerMoneyCopper_ = val;
                             LOG_INFO("Money set from update fields: ", val, " copper");
                         }
-                        // Parse quest log fields (stride 5, 25 slots)
-                        else if (key >= ufQuestStart && key < ufQuestEnd && (key - ufQuestStart) % 5 == 0) {
+                        // Parse quest log fields (stride varies by expansion: 5=WotLK, 3=Classic)
+                        else if (key >= ufQuestStart && key < ufQuestEnd && (key - ufQuestStart) % qStride == 0) {
                             uint32_t questId = val;
                             if (questId != 0) {
                                 // Check if quest is already in log
@@ -8306,7 +8307,9 @@ void GameHandler::selectGossipQuest(uint32_t questId) {
 
 void GameHandler::handleQuestDetails(network::Packet& packet) {
     QuestDetailsData data;
-    if (!QuestDetailsParser::parse(packet, data)) {
+    bool ok = packetParsers_ ? packetParsers_->parseQuestDetails(packet, data)
+                              : QuestDetailsParser::parse(packet, data);
+    if (!ok) {
         LOG_WARNING("Failed to parse SMSG_QUESTGIVER_QUEST_DETAILS");
         return;
     }

src/game/packet_parsers_classic.cpp

@@ -1154,5 +1154,69 @@ uint8_t ClassicPacketParsers::readQuestGiverStatus(network::Packet& packet) {
     }
 }
 
+// ============================================================================
+// Classic CMSG_QUESTGIVER_QUERY_QUEST — Vanilla 1.12 format
+// WotLK appends a trailing unk1 byte; Vanilla servers don't expect it and
+// some reject or misparse the 13-byte packet, preventing quest details from
+// being sent back.  Classic format: guid(8) + questId(4) = 12 bytes.
+// ============================================================================
+network::Packet ClassicPacketParsers::buildQueryQuestPacket(uint64_t npcGuid, uint32_t questId) {
+    network::Packet packet(wireOpcode(Opcode::CMSG_QUESTGIVER_QUERY_QUEST));
+    packet.writeUInt64(npcGuid);
+    packet.writeUInt32(questId);
+    // No trailing unk byte (WotLK-only field)
+    return packet;
+}
+
+// ============================================================================
+// Classic SMSG_QUESTGIVER_QUEST_DETAILS — Vanilla 1.12 format
+// WotLK inserts an informUnit GUID (8 bytes) between npcGuid and questId.
+// Vanilla has: npcGuid(8) + questId(4) + title + details + objectives + ...
+// ============================================================================
+bool ClassicPacketParsers::parseQuestDetails(network::Packet& packet, QuestDetailsData& data) {
+    if (packet.getSize() < 16) return false;
+
+    data.npcGuid = packet.readUInt64();
+    // Vanilla: questId follows immediately — no informUnit GUID
+    data.questId = packet.readUInt32();
+    data.title      = packet.readString();
+    data.details    = packet.readString();
+    data.objectives = packet.readString();
+
+    if (packet.getReadPos() + 5 > packet.getSize()) {
+        LOG_INFO("Quest details classic (short): id=", data.questId, " title='", data.title, "'");
+        return !data.title.empty() || data.questId != 0;
+    }
+
+    /*activateAccept*/ packet.readUInt8();
+    data.suggestedPlayers = packet.readUInt32();
+
+    // Choice reward items: variable count + 3 uint32s each
+    if (packet.getReadPos() + 4 <= packet.getSize()) {
+        uint32_t choiceCount = packet.readUInt32();
+        for (uint32_t i = 0; i < choiceCount && packet.getReadPos() + 12 <= packet.getSize(); ++i) {
+            packet.readUInt32(); // itemId
+            packet.readUInt32(); // count
+            packet.readUInt32(); // displayInfo
+        }
+    }
+
+    // Fixed reward items: variable count + 3 uint32s each
+    if (packet.getReadPos() + 4 <= packet.getSize()) {
+        uint32_t rewardCount = packet.readUInt32();
+        for (uint32_t i = 0; i < rewardCount && packet.getReadPos() + 12 <= packet.getSize(); ++i) {
+            packet.readUInt32(); // itemId
+            packet.readUInt32(); // count
+            packet.readUInt32(); // displayInfo
+        }
+    }
+
+    if (packet.getReadPos() + 4 <= packet.getSize())
+        data.rewardMoney = packet.readUInt32();
+
+    LOG_INFO("Quest details classic: id=", data.questId, " title='", data.title, "'");
+    return true;
+}
+
 } // namespace game
 } // namespace wowee