[MC-214293] Mobs can spawn on top of azaleas and flowering azaleas

Hostile mobs are able to spawn on top of azaleas and flowering azaleas.

To reproduce

Create a world

While in mid-air, type

/fill ~10 ~ ~10 ~-10 ~ ~-10 minecraft:moss_block

While standing on the moss block type

/fill ~10 ~ ~10 ~-10 ~ ~-10 minecraft:flowering_azalea

Set the time to midnight
Use
```
/kill @e[type=!player]
```
→ ❌ Mobs start to spawn on top of the azaleas

Linked issues

relates to 3

MC-174811 Zombified piglins are able to spawn on top of nether wart blocks Resolved

MC-266096 Mobs can spawn on oxidized or waxed copper grates Resolved

MCPE-148731 Hostile mobs can spawn inside azaleas and flowering azaleas Resolved

Attachments

Comments 9

[Mod] markderickson 2021-02-06T06:09:58Z

Can confirm.

Avoma 2021-02-11T16:10:13Z

Can confirm in 21w06a.

[Mod] OcelotOnesie 2021-11-21T22:13:26Z

Reopening, this was not fixed in 21w16a.

MMK21 2021-12-14T19:51:10Z

Affects 1.18.1

Leevi 2021-12-23T21:57:05Z

Still a major problem as of 23/12.

Avoma 2022-03-20T19:15:43Z

Can confirm in 1.18.2 and 22w11a.

Avoma 2022-06-21T16:44:17Z

Can confirm in 1.19 and 22w24a.

AMGAMES04 2023-11-10T14:38:38Z

Can confirm in 23w45a

Rampage455 2024-08-10T21:35:07Z

Is this actually a bug? A code analysis reveals that the only conditions on a block allowing spawning is that it has a solid top surface, and a luminance less than 14. Are we assuming that they are supposed to act like other saplings because they're part of the #minecraft:saplings block group? The block group doesn't appear to affect block properties. Azaleas have a solid top surface, they don't have a luminance, and they don't have an explicit override like some other blocks that restricts spawning. This may be intentional game design.