Before the Nether Update, I was able to take Book and Quills from a chest, in which the book and quill was constantly being replaced by another book and quill for an infinite source. Moving forward to the Nether Update launch, I cannot take the book and quill out of the chest.

Steps to Reproduce:
1. Have a Repeating Command Block on Always Active with the following command: "/replaceitem block ~ ~1 ~ slot.container 0 stick".
2. Place a chest on top of the command block.
3. Look inside the chest. There should be a stick in the first (0) slot. When you try to quick move or grab the stick with your cursor, it disappears.

Expected Results:

I am able to take out the stick, and there should be another stick in the same slot of the chest because of the command block.

Observed Results:

The stick you tried to take from the chest disappears, however, the stick is still being replaced in the "0" slot of the chest.