This is not a bug since by the game's logic you're actually one block lower - it's just a side effect of how mud, snow layers, soul sand have a different hitbox and a different collision box (which can be seen in the provided screenshots - look at Y values)
The problem is if this incorrect light value enables mobs to spawn on the block when they shouldn't. Which according to one comment in the thread it does.
While in a sense the code is working correctly it can hardly be the intended function since it means that it is impossible to light up and spawn proof these kinds of block without physically blocking spawning.
Tobias Harms
The problem is if this incorrect light value enables mobs to spawn on the block when they shouldn't. Which according to one comment in the thread it does.
While in a sense the code is working correctly it can hardly be the intended function since it means that it is impossible to light up and spawn proof these kinds of block without physically blocking spawning.