I found a duplication bug related to inventory management

[tawdry bluff]

Steps to reproduce:

1. Fill the inventory completely so there are no empty slots.
2. Have a single item (stack size = 1) in the inventory.
3. Press Shift + Right-click on that item.

Expected result:
Since the item is alone in its slot, nothing should happen, or the game should attempt to split the stack but fail due to the inventory being full.

Actual result:
The item duplicates — instead of splitting, a second copy of the item appears, effectively creating a stack of 2.

Additional notes:
This seems to happen only when the inventory is fully occupied and the item stack size is exactly 1.

[frosty kayak]

this also deletes any item that isnt stackable like weapons

[lime ore]

i want to add to it that it works without the inventory beeing full. the item just has to be placed with shift+left click to the highest place in the inventory as possible. when you click shift+right click it should duplicate too when its a single item.

[main gust]

It works for me with weapons, they are duplicated as well

[frosty kayak]

i tried it with some spare gear and it always got deleted

[main gust]

Not sure, I can dupe weapons. There is also a side effect that upgrades stack on top of each other if you upgrade the duped weapons over and over again

The weapons are stackable for me

Up to 2 at least