X-Ray when being inside of a piston head

The bug

If you active a piston head, so it goes inside your head you'll be able to see trough blocks. This can be used to search for caves, mineshafts and much more.

How to reproduce

1. Make a hole thats 1 wide, 3 long, and two height
2. Place a block with redstone torch on it, on one of the sides (See screenshot 'setup torch')
3. Place a piston on the torch, so the piston head will be inside your head
   → Observe how you can look trough blocks, see caves, lava, etc.