fix: NPCs drop gold on the ground when selling loot

src/creatures/npcs/npc.cpp

@@ -458,6 +458,39 @@ void Npc::onPlayerSellAllLoot(uint32_t playerId, uint16_t itemId, bool ignore, u
 		const auto preSize = container->size();
 		const uint64_t preTotal = totalPrice;
 
+		bool hasSellable = false;
+		const auto &shopVector = getShopItemVector(player->getGUID());
+		for (ContainerIterator it = container->iterator(); it.hasNext(); it.advance()) {
+			const auto &item = *it;
+			if (!item) {
+				continue;
+			}
+			uint32_t sellPriceCandidate = 0;
+			const ItemType &itemType = Item::items[item->getID()];
+			for (const ShopBlock &shopBlock : shopVector) {
+				if (itemType.id == shopBlock.itemId && shopBlock.itemSellPrice != 0) {
+					sellPriceCandidate = shopBlock.itemSellPrice;
+					break;
+				}
+			}
+			if (sellPriceCandidate == 0) {
+				continue;
+			}
+			if (item->getTier() > 0 || item->hasImbuements()) {
+				continue;
+			}
+			if (const auto &child = item->getContainer()) {
+				if (child->size() > 0) {
+					continue;
+				}
+			}
+			if (!item->hasMarketAttributes()) {
+				continue;
+			}
+			hasSellable = true;
+			break;
+		}
+
 		phmap::flat_hash_map<uint16_t, uint16_t> toSell;
 		uint32_t MAX_BATCH_SIZE = 10;
 		uint32_t processedCount = 0;
@@ -516,10 +549,22 @@ void Npc::onPlayerSellAllLoot(uint32_t playerId, uint16_t itemId, bool ignore, u
 		auto ss = std::stringstream();
 		if (!madeProgress) {
 			if (totalPrice == 0) {
-				ss << "You have no sellable items in your loot pouch.";
-				player->sendTextMessage(MESSAGE_FAILURE, ss.str());
+				if (preSize == 0) {
+					ss << "You have no items in your loot pouch.";
+					player->sendTextMessage(MESSAGE_FAILURE, ss.str());
+				} else if (!hasSellable) {
+					ss << "You have no sellable items in your loot pouch.";
+					player->sendTextMessage(MESSAGE_FAILURE, ss.str());
+				} else {
+					ss << "You don't have enough space. Free up space in your bag.";
+					player->sendTextMessage(MESSAGE_FAILURE, ss.str());
+				}
 			} else {
-				ss << "Finished selling. Some items in your loot pouch could not be sold.";
+				ss << "Sale stopped. Some items in your loot bag could not be sold. Make sure you have enough space in your bag.";
+				player->sendTextMessage(MESSAGE_ADMINISTRATOR, ss.str());
+				ss.str("");
+				ss.clear();
+				ss << "You sold all of the items from your loot pouch for " << totalPrice << " gold.";
 				player->sendTextMessage(MESSAGE_LOOK, ss.str());
 			}
 		} else {
@@ -559,6 +604,61 @@ void Npc::onPlayerSellItem(const std::shared_ptr<Player> &player, uint16_t itemI
 		return;
 	}
 
+	// Pre-check: compute how many items can be sold in this call (eligible) without removing yet
+	uint32_t eligibleCount = 0;
+	for (const auto &item : player->getInventoryItemsFromId(itemId, ignore)) {
+		if (!item || item->getTier() > 0 || item->hasImbuements()) {
+			continue;
+		}
+		if (const auto &container = item->getContainer()) {
+			if (container->size() > 0) {
+				continue;
+			}
+		}
+		if (parent && item->getParent() != parent) {
+			continue;
+		}
+		if (!item->hasMarketAttributes()) {
+			continue;
+		}
+		eligibleCount += item->getItemCount();
+		if (eligibleCount >= amount) {
+			break;
+		}
+	}
+
+	const uint32_t willRemove = std::min<uint32_t>(amount, eligibleCount);
+	if (willRemove == 0) {
+		return;
+	}
+
+	// Capacity and backpack space check for gold payouts (when not using autobank)
+	if (getCurrency() == ITEM_GOLD_COIN && !g_configManager().getBoolean(AUTOBANK)) {
+		const uint64_t prospectiveTotal = static_cast<uint64_t>(sellPrice) * static_cast<uint64_t>(willRemove);
+		uint32_t crystalCoins = static_cast<uint32_t>(prospectiveTotal / 10000);
+		uint32_t remainder = static_cast<uint32_t>(prospectiveTotal % 10000);
+		uint32_t platinumCoins = remainder / 100;
+		uint32_t goldCoins = remainder % 100;
+
+		// Number of stacks that will be created (each stack up to 100)
+		auto stacksNeeded = static_cast<uint16_t>((crystalCoins + 99) / 100 + (platinumCoins + 99) / 100 + (goldCoins + 99) / 100);
+		const uint16_t freeSlots = player->getFreeBackpackSlots();
+		if (stacksNeeded > 0 && freeSlots < stacksNeeded) {
+			player->sendCancelMessage(RETURNVALUE_NOTENOUGHROOM);
+			return;
+		}
+
+		// Capacity check (approximate by coin unit weights)
+		const uint32_t goldWeight = Item::items[ITEM_GOLD_COIN].weight;
+		const uint32_t platWeight = Item::items[ITEM_PLATINUM_COIN].weight;
+		const uint32_t crysWeight = Item::items[ITEM_CRYSTAL_COIN].weight;
+		const uint64_t totalWeight = static_cast<uint64_t>(goldCoins) * goldWeight + static_cast<uint64_t>(platinumCoins) * platWeight + static_cast<uint64_t>(crystalCoins) * crysWeight;
+		if (player->getFreeCapacity() < totalWeight) {
+			player->sendCancelMessage(RETURNVALUE_NOTENOUGHCAPACITY);
+			return;
+		}
+	}
+
 	auto toRemove = amount;
 	for (const auto &item : player->getInventoryItemsFromId(itemId, ignore)) {
 		if (!item || item->getTier() > 0 || item->hasImbuements()) {