Picking up backpack with full inventory deletes backpack

[Neohedron512]

Describe the bug

When you have no inventory space, and attempt to pick up a backpack, you "collect" it, but it isn't added to your inventory, nor is it added to your backpack slots. Learned this the hard way after dying and trying to pick up my inventory.

To Reproduce

1. Fill your inventory completely
2. Spawn a backpack with any contents
3. Attempt to pick it up

Expected behavior

Backpacks should either not be picked up when your inventory is full, or attempt to be inserted to your backpack slots when picked up with a full inventory.

Mod Version

3.0.3

Minecraft Version

1.21.1

Modloader

Neoforge 21.1.218

Crash Log (if applicable)

No response

Additional context

The backpack does not appear in the player's nbt anywhere.

[MrCrayfish]

I cannot reproduce the issue. Here is my test, and unless I did something wrong, please let me know. I've also shown that in creative mode items are picked up regardless if you inventory is full, and will delete the items. This is just normal vanilla behaviour, and not specific to backpacks.

2026-03-15.12-42-30.mp4