Torches and redstone torches on cobblestone wall appear to be floating

When regular torches or redstone torches are placed on cobblestone or mossy cobblestone walls they appear to be floating unless they are at the end of the wall or at a natural corner. I have been able to reproduce the error in creative and I had noticed it in survival at first.

What I expected to happen was...:
cobblestone wall usually looks raised under torches, no matter whether they are at a corner, end or in the middle of the wall.

What actually happened was...:
cobblestone wall only looked raised in end and corner position under torches, the torches along the straight walls appeared to float in the air above it.

Steps to Reproduce:
1. Place several blocks of cobblestone and/or mossy cobblestone wall next to each other
2. Place torches and/or redstone torches on top of the walls at positions other than corners or ends

Or: load map with cobblestone wall with torches at positions other than corners or ends (this is how I first noticed the glitch after 14w08a)