[MC-93271] Mushroom island ocean overlapping other biomes causing mobs to spawn on mushroom islands

The bug

Since the "Update that changed the world", mushroom island shore biome have not been generating properly around the edge of a mushroom biome.

How to reproduce

Seed: -640796280
Coordinates: /tp @s 29898.93 78.00 -8592.22 493.80 67.95

Linked issues

is duplicated by

MC-189753 Mushroom Island having mob spawning.

relates to

MC-236649 Mushroom islands sometimes don't generate properly

MC-126778 Phantoms can spawn above mushroom islands / mushroom fields

Attachments

Minecraft 1.16 Pre-release 5 - Singleplayer 2020-06-15 12-37-44.mp4

Comments

Kris Green 2016-02-12T02:35:54Z

i am also having this problem. there are supposed to be 3 mushroom islands on my map on X box One. but all i can find are oceans there no mycelium

seed: -1120300048038858764

user-f2760 2016-03-13T16:22:15Z

The enviroment is supposed to contain pc details

monkeybee 2016-03-13T17:49:44Z

oh sry my bad 😞 dont think it will matter to this bug but ill go find them now (any chance of a template so me know what it is accertly u want )

user-f2760 2016-03-13T17:54:02Z

just put down anything that relates to your pc enviroment
OS type/version
java version
drivers
etc

monkeybee 2016-03-13T18:00:28Z

ok apart form the OS me copyed what it says in the f3 screen on minecraft me think thats every thing u asked for sry if its not

user-f2760 2016-03-13T18:03:47Z

it's good now

user-2a4c8 2018-03-14T17:10:29Z

Seed: 16
World creation version: 18w11a
Area: West

wobst.michael 2018-03-14T17:42:31Z

@unknown, please provide coordinates...

violine1101 2018-03-14T18:19:17Z

Another example:

Seed: 108301
Location: 1758 / 1029
Version: 18w11a

Kraif 2018-08-27T16:08:59Z

Confirmed for 1.13.1.

Conem 2020-06-13T21:00:31Z

Confirmed in 1.16-pre5.

Butrint 2020-06-15T13:20:17Z

confirmed in 1.16-pre5 added a mp4 files showing mobs spawning in those grass_blocks
and a screenshot showing the grass_blocks within Minecraft:ocean biome instead of mushroom_field_shore.
seed : 1869945237501097058
coordinates : -2717 81 -3462

dagreenkat 2020-08-07T23:57:02Z

Confirmed in 1.16.1 on seed -350501890505856 near -323 85 -1315 in biome "mushroom_field_shore"

monkeybee 2020-10-13T23:20:26Z

comfirmed for 1.16.3 (cant give seed dont know it on smp)

Avoma 2020-12-13T17:29:05Z

Can confirm in 20w49a using the provided seed and coordinates.

Avoma 2021-01-24T11:57:37Z

Can confirm in 21w03a.

Avoma 2021-02-06T17:40:27Z

Can confirm in 21w05b.

Avoma 2021-02-19T15:46:06Z

Can confirm in 21w07a.

Marty McFly 2021-06-19T15:57:42Z

Affects 1.17

user-aa418 2021-08-14T18:16:52Z

Can confirm in 1.17.1.

monkeybee 2021-11-13T22:46:42Z

its still a thing in 1.18 pre1
seed -5730231953357368694
cords 7269 68 -25

Avoma 2022-07-26T12:10:04Z

Can confirm in 1.19.

[media]

Version: 1.19

Seed: -953538683905638291
Coordinates: /execute in minecraft:overworld run tp @s -808.79 73.86 1998.77 -409.87 45.17

Avoma 2022-09-15T14:35:27Z

Can confirm in 1.19.2.

Version: 1.19.2

Seed: -2178309719778189280
Coordinates: /execute in minecraft:overworld run tp @s -5792.10 69.25 -1546.76 -397.40 34.06

Cries 2022-11-21T20:29:59Z

I suspect this may also be an issue on Bedrock since I've had monsters spawn on my Bedrock mushroom island too, but Bedrock doesn't have any way to view what biome I'm in so I can't prove it.

Cries 2022-11-21T20:34:36Z

Is this also related to biome smoothing on the Y-axis?

Screenshot using MiniHUD to show ocean biome overlapping Mushroom Fields biome which allows monsters to spawn on a mooshroom island.

[media]

monkeybee 2023-05-23T13:00:46Z

its still a thing in 1.19.4

seed : -9175794540101132335

tp : /tp -1258 64 -4490