Two-Block Tall Flowers Drop Two Items When Block Below them is Broken

When the dirt below a two-block tall flower is broken, the flower drops two flowers instead of one, allowing duplicating.

I expected the flower to only drop one item, but instead it dropped two.

This bug works for world generated flowers and also flowers placed by hand. This bug has been in several snapshots before this one and has not yet been fixed.

Steps to Reproduce:
1. Place or find a two-block tall flower.
2. Break the block below the flower.
3. Flower drops two items.