Fixed variable type in npc.cpp

[EPuncker]

Pull Request Prelude

• I have followed proper The Forgotten Server code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

Changed from uint to int because we pass -1 at buy/sell

Issues addressed:
Closes #3980

[MillhioreBT]

For consistency with the expected value uint32_t we can't use int32_t since we would lose half of the available numbers, so we should use int64_t in this case

[nekiro]

For consistency with the expected value uint32_t we can't use int32_t since we would lose half of the available numbers, so we should use int64_t in this case

Or stop passing -1

[ramon-bernardo]

🤔

enum.h
struct ShopInfo {
	...
	uint32_t buyPrice = 0;
	uint32_t sellPrice = 0;
	...
};

[ranisalt]

LGTM

[ramon-bernardo]

Shouldn't we use price > 0?

bool Player::updateSaleShopList() {
    ...
    auto it = std::find_if(shopItemList.begin(), shopItemList.end(), [itemId](const ShopInfo& shopInfo) {
        return shopInfo.itemId == itemId && shopInfo.sellPrice != 0;
    });
    ...
}

bool Player::hasShopItemForSale() {
    ...
    return shopInfo.itemId == itemId && shopInfo.buyPrice != 0 && (!itemType.isFluidContainer() || shopInfo.subType == subType);
    ...
}

and price < 1 or price <= 0

void ProtocolGame::sendSaleItemList() {
    ...
    if (shopInfo.sellPrice == 0) { ... }
    ...
    if (shopInfo.sellPrice == 0) { ... }
    ...
}

[marmichalski]

This does not work as you think it does. This first converts both values to the template type (uint32_t). Since the buyPrice/sellPrice can be -1, this will just overflow and return that value instead of 0.

[EPuncker]

@nekiro

[MillhioreBT]

This does not work as you think it does. This first converts both values to the template type (uint32_t). Since the buyPrice/sellPrice can be -1, this will just overflow and return that value instead of 0.

Confirmed!
I guess a more explicit check should be done since buyPrice and sellPrice are of type int64_t

A possible solution:

uint32_t value = std::max<int64_t>(std::min<int64_t>(number, std::numeric_limits<uint32_t>::max()), 0);