New Minecraft Arrows Duplication In Snapshot 15W31A (Newest)

When I was playing with the sanpshot when I fired the new potion arrows it got duped!

I though when I went over to pick up my arrow from the ground it would add to my stack of 45 but it made a whole new stack! doubling my previous amount

but it made a whole new stack! doubling my previous amount
Steps to Reproduce:

Step 1: fire an arrow at the ground just one
Step 2:Pick up the arrow from the ground
Step 3: Be confused