[Affecting LIVE Content] Observers output a redstone signal if blocks are cloned and no block updates occur

Release_732213 from 1.2.13-beta-3

Summary: If a tile entity (i.e. a chest) is cloned from another destination to in front of an observer and the observer is pointed to a chest with the exact same contents and data as the chest being cloned, the observer will output a redstone signal despite no block updates actually taking place. The clone command will state that no blocks were cloned as the source and destination blocks are identical.

Impact: This potentially breaks systems where a player interacting with a chest will trigger an observer. (used in Enderman's forest)

Repro Steps:
1) Place an empty chest in front of an observer
2) Place a command block behind the observer with the command /say Triggered
3) Place another empty chest somewhere else away from the observer, but ensure it is facing the same direction as the chest in front of the observer.
4) Observe how both chests are identical...
5) Use the clone command to clone the chest from further away to the chest in front of the observer.
6) Observe how the clone command says "No blocks cloned" as both source and destination are identical.
7) Observe how also the command block was just powered by the observer despite no block updates taking place.

Observed Results: The observer outputs a redstone signal to the command block, despite no block updates occurring. (Or even if there are block updates, since the block has the same data as before the clone command, it should not be triggered and output a signal)

Expected Results: The observer should only output a redstone signal when the block in front of it has changed in some way. Whether that be changing to a different block or changing in data such as the direction of a chest or change in contents of a chest.

Screenshots/Videos attached: No