Add custom code to disable selling for vendors meeting specific criteria

In our case, we are keying off of stamina having a value of 789
Big thanks to Kayen for the code!

zone/client_packet.cpp

@@ -12361,6 +12361,7 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 	std::cout << "At 1: " << t1.getDuration() << std::endl;
 	return;
 }
+
 void Client::Handle_OP_ShopPlayerSell(const EQApplicationPacket *app)
 {
 	if (app->size != sizeof(Merchant_Purchase_Struct)) {
@@ -12373,9 +12374,24 @@ void Client::Handle_OP_ShopPlayerSell(const EQApplicationPacket *app)
 
 	Mob* vendor = entity_list.GetMob(mp->npcid);
 
+
 	if (vendor == 0 || !vendor->IsNPC() || vendor->GetClass() != MERCHANT)
 		return;
 
+	//CUSTOM - Prevent merchant from buying any items from players
+	if (vendor->GetSTA() == 789){ //Can change to this to whatever
+		EQApplicationPacket* outapp = new EQApplicationPacket(OP_ShopPlayerSell, sizeof(Merchant_Purchase_Struct));
+		Merchant_Purchase_Struct* mco = (Merchant_Purchase_Struct*)outapp->pBuffer;
+		mco->npcid = vendor->GetID();
+		mco->itemslot = -1;
+		mco->quantity = 0;
+		mco->price = 0;
+		QueuePacket(outapp);
+		safe_delete(outapp);
+		return;
+	}
+	//CUSTOM - End
+
 	//you have to be somewhat close to them to be properly using them
 	if (DistanceSquared(m_Position, vendor->GetPosition()) > USE_NPC_RANGE2)
 		return;