Another trade signs duplication glitch

[Myszku]

Type of bug

Exploit

/ess dump all output

https://essentialsx.net/dump.html?bytebin=B6eB0S73CH

Error log (if applicable)

https://pastebin.com/wAxAMU2a

Bug description

Apologies in advance for reporting a bug here without knowing exactly how to reproduce it, but unfortunately, the issue is serious, and I would like to ask for your help. Some time ago, I reported a similar bug (#6072) that was fixed, but unfortunately, my players have found another bug that allows item duplication.

Players are using [Trade] signs where they intend to buy a specific item. Another player clicks on the sign with the intention to sell, but the money from the sign and the sold item are not deducted from the player. However, the number of sold items increases.

I'm attaching an excerpt from the trade.log, where a player created a buy sign (trade) with $14,973. After 20 seconds, the sign was destroyed with the exact same amount of $14,973, but the player managed to extract 2,093 diamonds from it.

Players can duplicate any items this way, as long as they have at least one unit of the item and some money to create a buy sign. Please help me resolve this issue.

Steps to reproduce

As above.

Expected behaviour

Fix it.

Actual behaviour

Players duplicate whatever they want.

Additional Information

No response

[mbax]

Note: This server is running 1.18.2. There were lots of nasty duplication-causing bugs in the server itself around 1.16-1.19ish.

[Myszku]

I understand, but the bug I'm describing is specifically related to this plugin and Trade signs. I doubt it has anything to do with the server version.

[Myszku]

I managed to reproduce this bug. You need to create a sign like the one in the attached image:

With it, a simple trade shop will be created that buys items, for example, diamonds. When another player tries to sell items, they receive the message "This sign is full," but the number of purchased diamonds on the sign still increases, and nothing is taken from the player's inventory. When the shop owner destroys the sign, they will receive all those items. The key part here is the third line, it is the one that triggers the bug: $108.5:15000

Here is a link to the video: https://imgur.com/a/uK73lAd
And a new server dump: https://essentialsx.net/dump.html?bytebin=Cwb5vJIBTo