Placing a +DATA chest to the left of the original chest causes the contents of the original chest to disappear

Summary:

If you use Ctrl and middle mouse button to duplicate a chest and place it to the left of the original chest, the contents of the original chest will disappear.

Steps to Reproduce:

1. Open a superflat world and turn on creative mode.

2. Take a chest and a snowball.

3. Put your chest down and put the snowball in it.

4. Use Ctrl and Middle Mouse Button to duplicate the chest and place it on the left side of the original chest.

5. Open the chest on the right.

Observed Results:

You can't see anything in the chest.

Expected Results:

You should see a snowball in the chest.