Good afternoon. I found an error allowing you to dupe. If you are creating an item with a graphical interface, it looks like backpacks. After that, put one item in each of the backpacks. Then, with one backpack, we click several times on another, and the contents of one backpack are copied to another. Please note that you cannot exchange backpacks between each other. Say a player stores ore in one bag and a stone in another. The player will not be able to shift them among themselves, in addition, he will also be able to dupe the contents of one of the bags. This is a mistake on the part of the program, not the one who creates the mod.
Issue comments
Video bug demonstration: https://youtu.be/f6Qm95D_OCs
I was only talking about trying to swap backpacks in inventory. Putting into each other should naturally be prohibited. I'm talking about a different kind of bug. The game does not allow you to swap backpacks in one slot, instead, the game just copies one backpack erasing the old data
Please let me know how to check the video bug demonstration https://youtu.be/f6Qm95D_OCs
Turns out item handler is not synced to the client by default. I will add a "hack" to fix this in the next update.
Proper fix covered by this ticket: https://github.com/MinecraftForge/MinecraftForge/pull/6668
Unfortunately, the "hack" does still cause trouble in some cases. We will have to wait for https://github.com/MinecraftForge/MinecraftForge/pull/6668 likely
You should not be able to place backpack into another. Could you provide example workspace and demo feature how to exploit this?