I was testing the new arrows added in snapshot 15w31a, when I realized that picked up arrows multiplied. This only happens when using potion arrows.

What I expected to happen was...:
When I picked up a single arrow, it should have dropped only one arrow.

What actually happened was...:
Instead, it dropped as many arrows as were in the biggest stack in the inventory.

Steps to Reproduce:
1. Grab yourself any kind of potion arrows.
2. Fire a single one.
3. Notice that you pick up as many arrows as they were in the biggest stack in the inventory before you fired the arrow. (This happens even if the potion arrows are in the second hand slot)