Mojira Archive
MC-263753

Ultimate Infinite Furnace EXP abuse of shulker box exception

My server is messed up with this stuff and it's breaking the game balance.

PLease fix this as quick as you can!

Also related to MC-264054, the dupe/server lag method.

Check this:
https://www.youtube.com/watch?v=f4ty-PZcvrI

Suppressing Furnace Abuse with Fake Shulker Boxes:

https://www.youtube.com/watch?v=p5awe_hOp08

 

Explanation of the furnace abuse copied from discord:

the furnace breaks, it drops experience orbs frist and updates a comparator before deleting itself. but the shulker box exception can pause code execution and the furnace keeps itself but drop all the EXP. Put the furnace body back in place and the EXP will back again.

Explanation of the shulker box expection copied from discord:

https://cdn.discordapp.com/attachments/952854818265923604/1117718439860113458/2023-06-12_15-25-57.mp4
when shulker boxes calculate their comparator output, it does this logic

it will first cast its tile entity to an inventory, then feed it to a function that calculates the comparator output

(that function already includes casting logic and null checks, so there is no point in doing this cast; other containers don't have the cast too, but shulker boxes do)

therefore, if we can swap the tile entity of a non-inventory to a shulker box, then every time we update a comparator from this shulker box, it will throw a ClassCastException

in the video I swapped the tile entity of a lectern to a shulker box, and achieved this goal

this could work in 1.19, meaning that we will only need one initial OOM to make the ClassCastException suppressor, and then use this cast suppressor to do large scale suppressions

Fixed

turese

2023-06-22, 07:43 AM

2023-08-30, 04:59 PM

2023-08-30, 09:43 AM

1

3

Plausible

Very Important

Platform

Block states

1.20.1

23w35a