Fix for edge case of MatchableTypes being empty

Thanks @ezhevita

Author: JustArchi

ArchiSteamFarm.OfficialPlugins.ItemsMatcher/RemoteCommunication.cs

@@ -233,6 +233,7 @@ internal async Task OnPersonaState(string? nickname = null, string? avatarHash =
 			HashSet<EAssetType> acceptedMatchableTypes = Bot.BotConfig.MatchableTypes.Where(AcceptedMatchableTypes.Contains).ToHashSet();
 
 			if (acceptedMatchableTypes.Count == 0) {
+				// Should never happen, since IsEligibleForListing() check above ensured we have at least one matchable type
 				throw new InvalidOperationException(nameof(acceptedMatchableTypes));
 			}
 
@@ -905,9 +906,8 @@ private async void MatchActively(object? state = null) {
 		HashSet<EAssetType> acceptedMatchableTypes = Bot.BotConfig.MatchableTypes.Where(AcceptedMatchableTypes.Contains).ToHashSet();
 
 		if (acceptedMatchableTypes.Count == 0) {
-			Bot.ArchiLogger.LogNullError(acceptedMatchableTypes);
-
-			return;
+			// Should never happen, since IsEligibleForMatching() check above ensured we have at least one matchable type
+			throw new InvalidOperationException(nameof(acceptedMatchableTypes));
 		}
 
 		if (!await MatchActivelySemaphore.WaitAsync(0).ConfigureAwait(false)) {

ArchiSteamFarm/Steam/Exchange/Trading.cs

@@ -503,7 +503,7 @@ private async Task<ParseTradeResult> ParseTrade(TradeOffer tradeOffer, ISet<(uin
 		}
 
 		// Decline trade if we're requested to handle any not-accepted item type or if it's not fair games/types exchange
-		if (!tradeOffer.IsValidSteamItemsRequest(Bot.BotConfig.MatchableTypes) || !IsFairExchange(tradeOffer.ItemsToGive, tradeOffer.ItemsToReceive)) {
+		if (Bot.BotConfig.MatchableTypes.IsEmpty || !tradeOffer.IsValidSteamItemsRequest(Bot.BotConfig.MatchableTypes) || !IsFairExchange(tradeOffer.ItemsToGive, tradeOffer.ItemsToReceive)) {
 			Bot.ArchiLogger.LogGenericDebug(Strings.FormatBotTradeOfferResult(tradeOffer.TradeOfferID, ParseTradeResult.EResult.Rejected, $"{nameof(tradeOffer.IsValidSteamItemsRequest)} || {nameof(IsFairExchange)}"));
 
 			return ParseTradeResult.EResult.Rejected;