Bundle can be used for massive general item duplication

The bug

Due to some weird behavior of another bug, bundles are able to be stacked to 16. Using these bundles on items duplicates the item, since it creates 16 bundles containing the item.

How to reproduce

1. Right click on 2 or more bundles to get a bundle holding more than 1 bundle
2. Have a full inventory
3. Right click on the bundle to empty contents
4. Pick up the bundle stack off the ground. Notice how it is stacked
5. Now right click using these bundles on another item
   → The item has spread to all of the bundles, thus duplicating it