[Bug] Item Purchase Offset when multiple buyers are buying at the same time. (#4628)

* [Bug] Item Purchase Offset when multiple buyers are buying at the same time.

- Much of the code lifted from TAKP/P2002 and adapted
- Needs Testing
- This should help prevent situations where multiple people are purchasing items from a merchant and both attempt to purchase the same temp merchant or limited item, it should result in the later person recieving a notice that the item no longer exists and refreshes the merchant table.
- Updated strings

* fix formatting

* Push

* Update client.cpp

* Update database_update_manifest.cpp

* Update database_update_manifest.cpp

* Update database_update_manifest.cpp

* Update client.cpp

---------

Co-authored-by: Kinglykrab <kinglykrab@gmail.com>
Co-authored-by: Akkadius <akkadius1@gmail.com>

common/database/database_update_manifest.cpp

@@ -6394,7 +6394,7 @@ ALTER TABLE `trader`
 	ManifestEntry{
 		.version = 9297,
 		.description = "2024_01_22_sharedbank_guid_primary_key.sql",
-		.check = "SHOW COLUMN FROM `sharedbank` LIKE 'guid'",
+		.check = "SHOW COLUMNS FROM `sharedbank` LIKE 'guid'",
 		.condition = "empty",
 		.match = "",
 		.sql = R"(
@@ -6423,7 +6423,7 @@ ADD PRIMARY KEY (`account_id`, `slot_id`);
 		.version = 9298,
 		.description = "2024_10_24_inventory_changes.sql",
 		.check = "SHOW COLUMNS FROM `inventory` LIKE 'character_id'",
-		.condition = "missing",
+		.condition = "empty",
 		.match = "",
 		.sql = R"(
 ALTER TABLE `inventory`
@@ -6480,7 +6480,8 @@ UPDATE `inventory` SET `slot_id` = ((`slot_id` - 2261) + 10810) WHERE `slot_id`
 UPDATE `sharedbank` SET `slot_id` = ((`slot_id` - 2531) + 11010) WHERE `slot_id` BETWEEN 2531 AND 2540; -- Shared Bank Bag 1
 UPDATE `sharedbank` SET `slot_id` = ((`slot_id` - 2541) + 11210) WHERE `slot_id` BETWEEN 2541 AND 2550; -- Shared Bank Bag 2
 )",
-		.content_schema_update = false
+		.content_schema_update = false,
+		.force_interactive = true
 	},
 	ManifestEntry{
 		.version = 9299,

zone/client.cpp

@@ -13543,9 +13543,22 @@ std::string Client::GetBandolierItemName(uint8 bandolier_slot, uint8 slot_id)
 	if (
 		!EQ::ValueWithin(bandolier_slot, 0, 3) ||
 		!EQ::ValueWithin(slot_id, 0, 3)
-	) {
+		) {
 		return std::string();
 	}
 
 	return GetPP().bandoliers[bandolier_slot].Items[slot_id].Name;
 }
+
+void Client::SendMerchantEnd()
+{
+	SetMerchantSessionEntityID(0);
+
+	if (ClientVersion() == EQ::versions::ClientVersion::RoF2 && RuleB(Parcel, EnableParcelMerchants)) {
+		DoParcelCancel();
+		SetEngagedWithParcelMerchant(false);
+	}
+
+	EQApplicationPacket empty(OP_ShopEndConfirm);
+	QueuePacket(&empty);
+}

zone/client.h

@@ -1828,6 +1828,8 @@ public:
 
 	uint32 trapid; //ID of trap player has triggered. This is cleared when the player leaves the trap's radius, or it despawns.
 
+	void SendMerchantEnd();
+
 	Raid *p_raid_instance;
 
 	inline uint32 GetPotionBeltItemIcon(uint8 slot_id)

zone/client_packet.cpp

@@ -13952,14 +13952,7 @@ void Client::Handle_OP_Shielding(const EQApplicationPacket *app)
 
 void Client::Handle_OP_ShopEnd(const EQApplicationPacket *app)
 {
-    if (ClientVersion() == EQ::versions::ClientVersion::RoF2 && RuleB(Parcel, EnableParcelMerchants)) {
-        DoParcelCancel();
-        SetEngagedWithParcelMerchant(false);
-    }
-
-	EQApplicationPacket empty(OP_ShopEndConfirm);
-	QueuePacket(&empty);
-	return;
+	SendMerchantEnd();
 }
 
 void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
@@ -13980,14 +13973,16 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 	bool tmpmer_used = false;
 	Mob* tmp = entity_list.GetMob(mp->npcid);
 
-	if (tmp == 0 || !tmp->IsNPC() || tmp->GetClass() != Class::Merchant)
-		return;
-
-	if (mp->quantity < 1) return;
-
-	//you have to be somewhat close to them to be properly using them
-	if (DistanceSquared(m_Position, tmp->GetPosition()) > USE_NPC_RANGE2)
+	if (
+		tmp == 0 ||
+		!tmp->IsNPC() ||
+		tmp->GetClass() != Class::Merchant ||
+		mp->quantity < 1 ||
+		DistanceSquared(m_Position, tmp->GetPosition()) > USE_NPC_RANGE2
+	) {
+		SendMerchantEnd();
 		return;
+	}
 
 	merchantid = tmp->CastToNPC()->MerchantType;
 
@@ -14021,36 +14016,34 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 			}
 		}
 	}
+
 	item = database.GetItem(item_id);
+
 	if (!item) {
 		//error finding item, client didnt get the update packet for whatever reason, roleplay a tad
-		Message(Chat::Yellow, "%s tells you 'Sorry, that item is for display purposes only.' as they take the item off the shelf.", tmp->GetCleanName());
-		auto delitempacket = new EQApplicationPacket(OP_ShopDelItem, sizeof(Merchant_DelItem_Struct));
-		Merchant_DelItem_Struct* delitem = (Merchant_DelItem_Struct*)delitempacket->pBuffer;
-		delitem->itemslot = mp->itemslot;
-		delitem->npcid = mp->npcid;
-		delitem->playerid = mp->playerid;
-		delitempacket->priority = 6;
-		entity_list.QueueCloseClients(tmp, delitempacket); //que for anyone that could be using the merchant so they see the update
-		safe_delete(delitempacket);
+		MessageString(Chat::White, ALREADY_SOLD);
+		entity_list.SendMerchantInventory(tmp, mp->itemslot, true);
+		SendMerchantEnd();
 		return;
 	}
-	if (CheckLoreConflict(item))
-	{
-		Message(Chat::Yellow, "You can only have one of a lore item.");
+
+	if (CheckLoreConflict(item)) {
+		MessageString(Chat::White, DUPE_LORE_MERCHANT,tmp->GetCleanName(),item->Name);
 		return;
 	}
-	if (tmpmer_used && (mp->quantity > prevcharges || item->MaxCharges > 1))
-	{
-		if (prevcharges > item->MaxCharges && item->MaxCharges > 1)
+
+	if (tmpmer_used && (mp->quantity > prevcharges || item->MaxCharges > 1)) {
+		if (prevcharges > item->MaxCharges && item->MaxCharges > 1) {
 			mp->quantity = item->MaxCharges;
-		else
+		} else {
 			mp->quantity = prevcharges;
+		}
 	}
 
 	// Item's stackable, but the quantity they want to buy exceeds the max stackable quantity.
-	if (item->Stackable && mp->quantity > item->StackSize)
+	if (item->Stackable && mp->quantity > item->StackSize) {
 		mp->quantity = item->StackSize;
+	}
 
 	auto outapp = new EQApplicationPacket(OP_ShopPlayerBuy, sizeof(Merchant_Sell_Struct));
 	Merchant_Sell_Struct* mpo = (Merchant_Sell_Struct*)outapp->pBuffer;
@@ -14061,10 +14054,11 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 
 	int16 freeslotid = INVALID_INDEX;
 	int16 charges = 0;
-	if (item->Stackable || tmpmer_used)
+	if (item->Stackable || tmpmer_used) {
 		charges = mp->quantity;
-	else if ( item->MaxCharges >= 1)
+	} else if ( item->MaxCharges >= 1) {
 		charges = item->MaxCharges;
+	}
 
 	EQ::ItemInstance* inst = database.CreateItem(item, charges);
 
@@ -14079,23 +14073,24 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 		single_price *= Client::CalcPriceMod(tmp, false);
 	}
 
-	if (item->MaxCharges > 1)
+	if (item->MaxCharges > 1) {
 		mpo->price = single_price;
-	else
+	} else {
 		mpo->price = single_price * mp->quantity;
+	}
 
-	if (mpo->price < 0)
-	{
+	if (mpo->price < 0)	{
+		MessageString(Chat::White, ALREADY_SOLD);
 		safe_delete(outapp);
 		safe_delete(inst);
+		SendMerchantEnd();
 		return;
 	}
 
 	// this area needs some work..two inventory insertion check failure points
 	// below do not return player's money..is this the intended behavior?
 
-	if (!TakeMoneyFromPP(mpo->price))
-	{
+	if (!TakeMoneyFromPP(mpo->price)) {
 		auto message = fmt::format(
 			"Vendor Cheat attempted to buy qty [{}] of item_id [{}] item_name[{}] that cost [{}] copper but only has platinum [{}] gold [{}] silver [{}] copper [{}]",
 			mpo->quantity,
@@ -14115,8 +14110,10 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 	}
 
 	bool stacked = TryStacking(inst);
-	if (!stacked)
+
+	if (!stacked) {
 		freeslotid = m_inv.FindFreeSlot(false, true, item->Size);
+	}
 
 	// shouldn't we be reimbursing if these two fail?
 
@@ -14130,8 +14127,7 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 		}
 	}
 
-	if (!stacked && freeslotid == INVALID_INDEX)
-	{
+	if (!stacked && freeslotid == INVALID_INDEX) {
 		Message(Chat::Red, "You do not have room for any more items.");
 		safe_delete(outapp);
 		safe_delete(inst);
@@ -14142,11 +14138,12 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 	if (!stacked && inst) {
 		PutItemInInventory(freeslotid, *inst);
 		SendItemPacket(freeslotid, inst, ItemPacketTrade);
-	}
-	else if (!stacked) {
+	} else if (!stacked) {
 		LogError("OP_ShopPlayerBuy: item->ItemClass Unknown! Type: [{}]", item->ItemClass);
 	}
+
 	QueuePacket(outapp);
+
 	if (inst && tmpmer_used) {
 		int32 new_charges = prevcharges - mp->quantity;
 		zone->SaveTempItem(merchantid, tmp->GetNPCTypeID(), item_id, new_charges);
@@ -14159,8 +14156,7 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 			delitempacket->priority = 6;
 			entity_list.QueueClients(tmp, delitempacket); //que for anyone that could be using the merchant so they see the update
 			safe_delete(delitempacket);
-		}
-		else {
+		} else {
 			// Update the charges/quantity in the merchant window
 			inst->SetCharges(new_charges);
 			inst->SetPrice(single_price);
@@ -14219,6 +14215,7 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 	safe_delete(inst);
 	safe_delete(outapp);
 }
+
 void Client::Handle_OP_ShopPlayerSell(const EQApplicationPacket *app)
 {
 	if (app->size != sizeof(Merchant_Purchase_Struct)) {
@@ -14522,6 +14519,8 @@ void Client::Handle_OP_ShopRequest(const EQApplicationPacket *app)
 
 	if (action == MerchantActions::Open) {
 		BulkSendMerchantInventory(merchant_id, tmp->GetNPCTypeID());
+		SetMerchantSessionEntityID(tmp->GetID());
+
 		if ((tabs_to_display & Parcel) == Parcel) {
 			SendBulkParcels();
 		}

zone/entity.cpp

@@ -5950,3 +5950,53 @@ std::vector<NPC*> EntityList::GetExcludedNPCsByIDs(std::vector<uint32> npc_ids)
 
 	return v;
 }
+
+void EntityList::SendMerchantEnd(Mob* merchant)
+{
+	for (const auto& e : client_list) {
+		Client* c = e.second;
+
+		if (!c) {
+			continue;
+		}
+
+		if (c->GetMerchantSessionEntityID() == merchant->GetID()) {
+			c->SendMerchantEnd();
+		}
+	}
+}
+
+void EntityList::SendMerchantInventory(Mob* m, int32 slot_id, bool is_delete)
+{
+	if (!m || !m->IsNPC()) {
+		return;
+	}
+
+	for (const auto& e : client_list) {
+		Client* c = e.second;
+
+		if (!c) {
+			continue;
+		}
+
+		if (c->GetMerchantSessionEntityID() == m->GetID()) {
+			if (!is_delete) {
+				c->BulkSendMerchantInventory(m->CastToNPC()->MerchantType, m->GetNPCTypeID());
+			} else {
+				auto app = new EQApplicationPacket(OP_ShopDelItem, sizeof(Merchant_DelItem_Struct));
+				auto d   = (Merchant_DelItem_Struct*)app->pBuffer;
+
+				d->itemslot   = slot_id;
+				d->npcid      = m->GetID();
+				d->playerid   = c->GetID();
+
+				app->priority = 6;
+
+				c->QueuePacket(app);
+				safe_delete(app);
+			}
+		}
+	}
+
+	return;
+}

zone/entity.h

@@ -578,6 +578,9 @@ public:
 
 	int MovePlayerCorpsesToGraveyard(bool force_move_from_instance = false);
 
+	void SendMerchantEnd(Mob* merchant);
+	void SendMerchantInventory(Mob* m, int32 slot_id = -1, bool is_delete = false);
+
 protected:
 	friend class Zone;
 	void	Depop(bool StartSpawnTimer = false);

zone/mob.cpp

@@ -493,6 +493,8 @@ Mob::Mob(
 	m_AllowBeneficial = false;
 	m_DisableMelee    = false;
 
+	SetMerchantSessionEntityID(0);
+
 	for (int i = 0; i < EQ::skills::HIGHEST_SKILL + 2; i++) {
 		SkillDmgTaken_Mod[i] = 0;
 	}

zone/mob.h

@@ -1387,6 +1387,9 @@ public:
 	std::string GetRacePlural();
 	std::string GetClassPlural();
 
+	inline void SetMerchantSessionEntityID(uint16 value) { m_merchant_session_entity_id = value; }
+	inline uint16 GetMerchantSessionEntityID() { return m_merchant_session_entity_id; }
+
 	//Command #Tune functions
 	void TuneGetStats(Mob* defender, Mob *attacker);
 	void TuneGetACByPctMitigation(Mob* defender, Mob *attacker, float pct_mitigation, int interval = 10, int max_loop = 1000, int atk_override = 0, int Msg = 0);
@@ -1920,6 +1923,8 @@ protected:
 
 	MobMovementManager *mMovementManager;
 
+	uint16 m_merchant_session_entity_id;
+
 private:
 	Mob* target;
 	EQ::InventoryProfile m_inv;

zone/string_ids.h

@@ -286,6 +286,7 @@
 #define BEGINS_TO_SHINE				1238	//Your %1 begins to shine.
 #define CANT_FIND_PLAYER			1276 	//I can't find a player named %1!
 #define SURNAME_REJECTED			1374	//Your new surname was rejected. Please try a different name.
+#define ALREADY_SOLD				1376	//The item you were interested in has already been sold.
 #define GUILD_DISBANDED				1377    //Your guild has been disbanded!  You are no longer a member of any guild.
 #define DUEL_DECLINE				1383	//%1 has declined your challenge to duel to the death.
 #define DUEL_ACCEPTED				1384	//%1 has already accepted a duel with someone else.
@@ -308,6 +309,7 @@
 #define PLAYER_CHARMED				1461	//You lose control of yourself!
 #define TRADER_BUSY					1468	//That Trader is currently with a customer. Please wait until their transaction is finished.
 #define SENSE_CORPSE_DIRECTION		1563	//You sense a corpse in this direction.
+#define DUPE_LORE_MERCHANT			1573	//%1 tells you, 'You already have the lore item, %2, on your person, on your shroud, in the bank, in a real estate, or as an augment in another item.  You cannot have more than one of a particular lore item at a time.'
 #define QUEUED_TELL					2458	//[queued]
 #define QUEUE_TELL_FULL				2459	//[zoing and queue is full]
 #define TRADER_BUSY_TWO             3192    //Sorry, that action cannot be performed while trading.