What I expected to do:
Plant a mushroom in open sky area, in darkness. It stays... in least till sunup or bonemeal into giant mushroom.

What really happened:
Mushroom pops off, even in middle of night and very dark.

I understand why blocks is permanently 15 if open to sky due to lag on changing all blocks lighting... but..

Mobs can spawn in night even on blocks on "15" light level. Why can't mushrooms be planted? Here is pseudocode on how it should work.

realBlockLightLevel is function that gets block real light level like used for mobs for spawning. blockLightLevel just gets block current light level.
Using . as space

(planted tick functions)
if(openToSky == true)
...if(night == false)
......dropMushroomAsResource
...elseif(realBlockLightLevel >= 13)
......dropMushroomAsResource
elseif(blockLightLevel >= 13)
...dropMushroomAsResource

I do hope its possible. I'm tired of building roofs so I can place wherever giant mushrooms I want by simply just planting in night and using mealbone.