This is a bug where when lava/water is placed atop snow, it floats above it instead of replacing it

Put the summary of the bug you're having here

What I expected to happen was...:
When i place lava/water on top of snow it would replace it

What actually happened was...:
It floated on top of it without replacement of snow

Steps to Reproduce:
1. Get lava/water bucket in hand
2. Find snowy area
3. Place water/lava on top of snow