Duplication Bug - Drop/Pickup

[Danekjovax]

In short:

1. Take an item and drop it on the ground - far enough away to not allow vanilla mechanics to pick it back up.
2. Walk towards dropped item, at the same time as right-clicking item.
3. (Sometimes) Profit!

Works in SSP and SMP, though timing is a lot tighter in the latter due to network latency. This works on single or multiples of the same item, mixed items in same pile, and items with inventories (IE crates/shulker boxes/etc.) and duplicates their inventories to the dupes items!

Here's some shots for proof:

SSP before/after:

SMP before/after:

Original issue post:
Freebi85/Dungeons-Dragons-Space-Shuttles#339

Thank you for your time, and I pray this can be resolved.