Can't Right-click to take half of the items in the brewing stand.

What I expected to happen was...:
When I right click on the effecting material (For example: sugar) to take half of it- it will.

What actually happened was...:
It gave me all the items but it looked like 1 item only. until I tried to take it again.

Steps to Reproduce:
1. Put a few items in the brewing stand(the top slot).
2. Right-click these items.
3. Put it in your inventory/