Cloning items (trade sign)

[luqsq]

Type of bug

Exploit

/ess dump all output

Error while creating dump...

Error log (if applicable)

No response

Bug description

We can cloning items (which don't stack) via "Trade" signs on version 1.12-1.18

https://www.youtube.com/watch?v=wJB_RvHu7gU

Steps to reproduce

https://www.youtube.com/watch?v=wJB_RvHu7gU

Expected behaviour

fix it?

Actual behaviour

.

[luqsq]

https://bytebin.lucko.me/blzqHo9bxr

[luqsq]

New 1.17 server (only 3 plugins: EssentialsX, Vault, LuckPerms)

https://www.youtube.com/watch?v=Q1ezmx5sEU0
https://www.youtube.com/watch?v=CpPtUUlOOmk

For example:
"lava_bucket " -> I can copy
"lavabucket "-> I CAN'T copy

[luqsq]

ess dump:
https://essentialsx.net/dump.html?id=c4ad8313f2154e378c62ae3a0a40a64b

[Evidentsinger14]

Additional information:
Was successfully able to replicate on the Latest Paper 1.17.1, and Paper 1.18.1, using Build 2.19.2

For Triage team: Note the amount of free spaces in your inventory. For the number on the sign, subtract 10 from it. You should have least that many slots in your inventory (Tested with 20 items on sign, and 10 slots in inventory. Tested with 30 items on sign, and 20 inventory slots)

Dump: https://essentialsx.net/dump.html?id=babd8e35ee4e4595a277be8968d3470c
Video: https://youtu.be/4bypTS8QlqM

Exact steps to replicate: (after perms have been given, and sign enabled)

1. Get 30 Non-Stackable items
2. Get 16 stone blocks (enough to leave at least 10 items in the sign when you break it)
3. Create trade sign, as shown in videos
4. Use your filler items, and put 1 in each slot
5. Try to break Sign
6. Profit