Entities standing on mud or soul sand next to lava are set on fire and take damage

I was trying to remove some annoying lava in the nether and was working near some soulsand. I happened to walk on it, and I found myself on fire. I tried again, and found that by walking/sneaking on an edge next to lava, it would cause me to catch on fire. This may occur with farmland as well... This is especially dangerous in the nether, as being on fire can easily be fatal.

What I expected to happen was...:
Walking on soulsand over the edge of lava would behave just like any other block.

What actually happened was...:
Walking on soulsand over the edge of lava caused me to catch fire.

Steps to Reproduce:
1: Have soulsand.
2: Make sure lava is touching the soulsand, on the same level.
3: Walk up to the edge and overhang the lava, while still on the soulsand, without slipping.
4: Notice how you are now on fire.