The bug

Shift clicking the result of a cartography table while holding an item with the cursor will delete this item.

How to reproduce

1. Create a filled map
2. Give yourself paper
3. Give yourself an unrelated item, for example stone
4. Put the map and paper in the cartography table
5. Pick up the unrelated item
6. Shift click the result map while still holding the item
   → The held item is deleted