NOTE: This bug happened when i was in survival, i changed to both spectator and creative to take screenshots. 

What I expected to happen was...:
nothing. Lighting shouldn't change

What actually happened was...:
As i was afk fishing chunks started going dark, THIS IS NOT JUST A VISUAL BUG like it was in previous versions.  it allows mobs to spawn on these sudo light level 0 blocks even if there are torches directly on the block theyre spawning on. 

Steps to Reproduce:
1. stand on the same block for an extended period of time (Multiple hours in real time)
2. walk around either above ground in the day time or bellow ground at any time and notice even if there are torches on blocks they look fully dark.