Minecraft 1.8, Minecraft 1.8.1-pre4, Minecraft 1.8.1, Minecraft 15w36d, Minecraft 15w42a, Minecraft 15w44a, Minecraft 15w44b, Minecraft 15w45a, Minecraft 15w46a
Somehow, the game consider that a "block" of 7 snow layers is a full block allowing player and snowmen to place a new snow layer block on top of it.
-What I expected to happen was...
That a snow man could not place a snow layer on top of a pile of 7 snow layers. It should place it only on top of a pile of 8 snow layers.
-What actually happened was...
When a snowman walks over a full block then continue over a 7 layer snow layer block, it create a layer of snow floating. Also happens when he jumps on an block of 7 layer of snow. But not when he climb on with slab of lower snow layer block. Somehow, the snowman don't "fall" when passing over a pile of 7 snow layers and drop another snow layer on top as if the 7 snow layers where a complete block. So you have 7 piled snow layer, 1 layer with nothing and 1 layered snow on top.
The player can create the same kind of pile as long as there is a block behind the pile.
Steps to reproduce: (Snowman)
1- Place any block with 2 snow block over it (this will become our snowman later)
2- Place a snow block right in front of our future snowman
3- Create piles of 7 snow layers around the snow block
4- Add the pumpkin to complete the snow man of step 1
5- And push him over the snow block and snow layers.
Voila. Floating snow layer.
Steps to reproduce: (Player)
1- Create a 1 block wide tower of any solid block
2- Create piles of 7 snow layers beside the tower
3- Look at the second block of the tower, on the same side you just put the snow
4- Place the snow layer. The game will allow you to, even if the 8th layer of the snow pile bellow is missing.