[BUG] Grass breaks blocks

[BrekiTomasson]

If you have a grass block with one block of air above it, and then any block above that, then any "tall grass" that grows in that spot will replace the block in question. So there needs to be an air-check for two blocks above grass before allowing tall grass to grow in a spot.

[BrekiTomasson]

Any news on this? It's fairly easy to test, just set up a bunch of grass blocks, leave one block of air above it and then place, for example, oak slabs in the space above that air block. Try it yourself by running these three commands (without moving between them, of course ;) ). You'll get a 30x30 area of grass blocks with one space and one layer of oak slabs above that, 10 blocks above you:

/fill ~ ~10 ~ ~30 ~10 ~30 minecraft:grass_block
/fill ~ ~11 ~ ~30 ~11 ~30 minecraft:air
/fill ~ ~12 ~ ~30 ~12 ~30 minecraft:oak_slab[type=bottom]

Wait long enough and you'll see this happening: