Mobs can spawn on moving blocks (block 36)

I'm unable to reproduce this in 19w42a.

It's easiest to reproduce in an otherwise empty world.
Even if you have a glass floor, I think mobs still try to spawn there and then abort the attempt later.

With a void world (don't simply use the preset the void, mobs can't spawn in the void biome), I was able to reproduce it in 42a easily.

Hmm, yeah, I tested this in an empty flatland world way above the ground, where it didn't work. But I checked again with a plains biome world, and mobs spawned. Not many, but they spawned.

can confirm in 1.18.1

Relates to MC-123217, if it is not to be merged into it.

Hello. I am the one who reported the bug.

MOJANG-san, could you please reconsider the priority of fixing this?

This bug is very troublesome for people who make flying machines. Spawning cannot be stopped by lighting such as sea lanterns and glowstone, or glass blocks. The only blocks that can stop spawning are limited blocks such as bottom slabs. This applies to all circuits that move blocks with pistons.(I am Japanese. Use Google Translate.)