I didn't see this in the bug overview/sumary thing, so I am assuming noone has posted this already.
Whilst I was crafting, say i was making a wolf necklace requiring 1 thread and 10 wolf teeth...
If i had 11 wolf teeth, it would consume only 1 and i would still have 10.
This also happened with making cloth, requiring 5 thread. I had 7 thread, and i got a cloth, leaving 5 thread in my inventory.
I then crafted 2 more thread with 1 fibre, and did it again succussfully another 10 or so times in a row, costing me only 22 threads instead of 55 threads, which is a HUGE difference. It always seemed to drop it to a multiple of the required amount. This could be used to break the market on much higher tier/more difficult items to craft with multiple rare drops of the same type required.
I don't know if it was the cause of another bug i found though... I couldn't figure out how to auto loot corpses, so I was manually dragging the meat and stuff into my inven. If i had a stack of 9 in my inventory, and dragged a stack of say 4 on top of it, i would end up with a stack of 10 and no second stack of 3. The item i dragged wouldn't end up back in the creatures inventory either... just... gone. It happened with any pair of stacks that would total to over 10, not just a stack of 9 in my inven and a stack of 2 or higher on the creature. I am pretty sure it didnt happen with chests though.