Mobs don't spawn on snow

[RalphKastro]

I'm not sure if I have a botched install, as something similar has happened before, so if somebody could confirm this as a bug I'd be very grateful.

I was noticing a strange lack of mobs in my current snowy hardcore spawn, so to test it out I made a creative flatland snowy world, and a small fenced area without snow. As expected, mobs only spawned on the uncovered blocks.

[FlowerChild]

Just confirmed this on my end. Looking into it.

[FlowerChild]

Believe it or not, it appears this is vanilla problem specific to superflat worlds. Haven't tried it myself, but I'm pretty sure if you try the same test with vanilla 1.5.2 the same thing will happen.

I believe it would decrease (not eliminate) spawning in snowy areas, or those with a lot of other ground cover like tall grass, in regular worlds though, so I'll see what I can do with it.

EDIT: Yeah, just tried it superflat in vanilla. Same bug.