Duplication issue with nearly full inventory and shift-click

[Belgabor]

Sometimes the easy crafting table does not properly recognize that there is not enough room for intermediate surplus items (could also affect side products, like empty buckets). If you craft the item by shift-clicking, no resources will be consumed.

http://imgur.com/a/BBbjW

[Belgabor]

I think this happens when the table would need exactly that one free slot you are shift-clicking into for extra material.