Clicking other potion effect arrows in creative menu with one in your hand adds more arrows, and doesn't discard them.

What I expected to happen was...:
The arrows would be discarded.

What actually happened was...:*
Clicking other potion effect arrows produces more of the ones in your hand, instead of discarding them,

Steps to Reproduce:
1. Pick up a potion effect arrow in the creative inventory and place it in your hotbar.
2. pick the arrows up and click a different type of potion effect arrow.
3. The arrows will not be discarded, but add more of the same one, even if you are not clicking the same type.