I've just received trade offer from Endorlight game which used different combinations of classID/instanceID for the same items, such as <1450080555, 246376127> and <1450080555, 0> for Birdy trading card.
This is the first time I've seen something like that, as up to this point all classID + instanceID matched nicely. It's not good because it results in possibly wrong results regarding numbers of the same cards.
It's not any major problem scamming-wise, as ASF does other checks (including appID checks) so in worst case we could accept a trade that is not neutral+ for us, such as 1 -> 2 dupes one.
This commit fixes wrong logic for that particular trade I've encountered, and many similar ones, but I have no idea if we can really base key on classID only.
Number seems big enough to fit all steam items, but if there ever happens item that will have same classID as other one, we'll be in deep sh*t.
I ran a test on my Steam account with 7.5k+ items and didn't find any item which could cause such conflict, so I can at least assume that the issue doesn't exist for majority of Steam users.
Sadly there doesn't seem to be any good way to solve it either, as if such conflicts happens, then we will have 3 items such as <7, 1>, <7, 4> and <7, 0>. We can't know if 0 should be 1 or 4 (thanks GabeN).
This seems to be best solution for that problem, and until we find clasID conflict, we can sleep in peace.
Previously we had rather half-blind mechanism of trying to play given games, expecting a disconnect, and reconnecting in AccountPlayingDelay minutes. Now instead we have proper event-based handling - ASF listens on each PlayingSessionState event and updates availability of farming accordingly, not only resuming farming immediately after it's possible, but also limiting number of reconnects and other issues which could be caused by previous approach.
I bet this can be even further improved to not receive LoggedInElsewhere and disconnect error when user starts playing a game, but that's misc compared to gigantic improvement in this commit
