Potential cause found for the AH "items not selling" bug

[Veracor]

The bug where items refuse to sell unless you relist them for slightly different prices has been a topic of discussion many times in the HC Discord and other places.  Many have assumed it was a database error or something getting lost in communication between servers since the code seemed fine, and the solution was to take the item back and relist it for a couple of inf higher/lower, and just deal with losing inf from the relisting fee.

 

Well, I just found one way to replicate it: the "block" happens when someone attempts to buy the same items they're selling, causing everyone else's items behind it to not sell for that exact price.

 

To test this, I logged on three accounts and then drained one item down to 0 sellers and 0 bids.  I did this with the small dual inspiration "Shielded" for testing:

 

Account (A) then bid 12 inf on one and also posted one for 12 inf.

Account (B) then bid 12 inf on one.

This screenshot shows Account (B)'s window not successfully buying it:

 

Account (C) then made a 12 inf bid on it.

Account (A) then rescinded its own 12 inf bid.

The moment (A) rescinded its own bid, (A)'s inspiration sold to Account (C):

 

So that may explain some situations when people are posting a bunch of ATOs for 7000000 or something and not getting sales, but people posting for something like 7000005 are.  But the testing didn't stop there!

 

Here, Account (A) listed its inspiration again with no bids from (B) or (C), but this time (A) bid for 12000 inf instead of the 12 inf it's listing at:

 

Account (B) could only buy the inspiration if it beat (A)'s stuck bid, even though (A)'s listing price was far lower than the bids:

 

This pretty much lets sellers of low-supply items bypass listing fees by bidding the price they want to get and then listing their item for 1 inf, since nobody can beat their own bid because the AH does not let players sell to themselves and this causes the queue to get stuck.  This facet of the bug is not much of an exploit since it's just a 5% fee, but there might be additional shenanigans that I haven't thought of.

 

The predicted fix would be to the auction server's code to make the queue jump over entries where the buyer and seller are the same person.  However, it would probably be enough of a fix to just put a PSA or something on the AH's interface to simply not bid on your own items.

 

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Edit: And one other thing I noticed when doing these tests is that I could:

 

(A) "stucks" the supply of the item with a bid and then lists 10 of the items.

(B) and (C) both bid for 10 of the items, for the stuck price.

(A) rescinds its stuck bid.

(B) and (C) share the 10 items at complete random.

 

I don't know about selling (it should be a queue), but buying apparently does not care about the order of the bidders.

Edited September 13, 2020 by Veracor

[Keen]

8 minutes ago, Veracor said:

...not bid on your own items

That probably includes items that share inventory.

 

Practical example: I got a crafted, Level 50 PvP IO that I don't want, because I use Attuned. So I list the crafted IO then bid on the same attuned one. Since they share inventory, that might count as "bidding on your own item".

[Veracor]

5 minutes ago, Keen said:

That probably includes items that share inventory.

Yes, I did not explicitly test for fungibility with this bug, but I see no reason why it wouldn't happen as they're just all put into the same buckets and then converted based on what's being requested by the AH UI or the buyer themself.

 

So items that can be exchanged with each other on the AH, as well as items being bought/sold in bulk like boosters and such, are more susciptible to having "stuck" prices among the sellers (and I would imagine 99% of these are accidental).  Inspirations was perhaps a poor choice for testing this with since they're not fungible, but they were easy to get an undesirable item to 0 sellers 0 bids for testing (and that nobody else would make bids on or posting new ones while testing).

Edited September 12, 2020 by Veracor

[EmmySky]

And thanks @Veracor for buying my stock..I thought those would never move 😁

[Xanatos]

I just did the following on the test server on an item that was 0/0 selling/bids:

 

Account A bids 2bil for item
Account A lists item for 1inf
Account B bids 2bil for item, cannot buy
Account C lists item for 10inf
Account C's item is sold to Account A for 2bil
Account A's item is sold to Account B for 2bil

 

The "lock" only applies on Account A's items. Other accounts are still free to sell the item for a lower price.

Edited September 14, 2020 by Xanatos