(Sticky) Pistons with a Data Value of 6 have no texture

In my snapshot world I have used "/setblock ~ ~ ~ piston 6" and "/setblock ~ ~ ~ sticky_piston 6" to create the "Crate" blocks (A block with the Piston head texture on all sides). I have not used the world in a while but I opened it up in 14w17a and those blocks wereusing the "Missing Texture" texture.

What I expected to happen was...:
To walk into my building and see the "Crates".

What actually happened was...:
I walked into my building and found Missing Textures.

Steps to Reproduce:
1. Create a world in a 1.8 snapshot that isn't 14w17a.
2. Use "/setblock ~ ~ ~ piston 6" and "/setblock ~ ~ ~ sticky_piston 6"
3. Load up the world in 14w17a. You will find the missing textures!