I was in a creative world with an enchanted sword and this bug came up.

Reproduce it:

1. Play a world on multiplayer or singleplayer.
2. Get a tool or weapon.
3. Enchant it.
4. Make sure that you don't any resource/texture pack which changes the enchant overlay.
5. Note closely the pixels, becomes more noticeable when you move the camera.
6. There is z-fighting.

What I expected to happen:

The enchant overlay works properly.

What happened:

 The enchant overlay was overlapping the item texture.