The Bug:
Decorations and terrain can generate inside of structures.
Just for clarification reasons, decoration blocks are blocks such as grass, ferns, seagrass, etc...
Here are some examples:
Version: 1.21.4
Seed: -6533926018995126751
Coordinates: /execute in minecraft:overworld run tp @s 171 68 869
Steps to Reproduce:
Generate a world with any of the seeds provided above and teleport to the given coordinates.
Look closely at the terrain/decorations inside the said structure.
Take note as to whether or not decorations and terrain can generate inside of structures.
Observed Behavior:
Decorations and terrain can generate inside of structures.
Expected Behavior:
Decorations and terrain would not be able to generate inside of structures.
Related issues
is duplicated by
relates to
Attachments
Comments


I reopened this report now to be about the new 1.14 villages only, while MC-23830 will be only about the old villages.
Please provide seeds and coordinates where this bug can be seen.

@Marcono1234 https://www.bilibili.com/video/av37606008
Confirmed for 19w14b

still happens in 1.14 307,73,334 SEED: 4878702018839826212
Confirmed for 1.14.1 and 1.14.2 Pre-Release 2

Confirmed for 1.15.2 and 20w10a

Same here. I saw grass in a village house.

In 1.16.1 and 20w29a
Can confirm that this is still an issue. I've attached a screenshot along with a seed and coordinates of this issue occurring.
Seed: -5436467103508185805
Coordinates: /execute in minecraft:overworld run tp @p 21310 69 279 180 -45
Can confirm in 21w03a.
Can confirm in 21w05b.

Grass and stone spawning on ceiling in a mansion, so confirmed for 1.16.5.

This happens because some structures have void blocks inside them, which will keep whatever block was in that place. A lot of them were fixed.
Ideally, there would be an exact list of the structures that have this issue, but that is a lot of work. Structures would need to be manually generated completely submerged in a flat world, to make sure they properly remove the terrain inside.

Does this stretch to include tall grass without dirt or grass under it?

This can be easily reproduced by finding taiga_medium_house_1 or desert_toolsmith_1 in a naturally generated village.

This also affects flowers; can confirm in 1.17.1 and 21w37a.
Can confirm in 1.18 Pre-release 1.
[media][media]Version: 1.18 Pre-release 1
Seed: -4534856491544025661
Coordinates: /execute in minecraft:overworld run tp @s 29243.48 67.00 130.36 -396.48 -14.48

The image 2021-02-14_14.22.03.png actually showcases MC-107594, which has a very different cause.
I'd still link them as related though, as it may look like the same bug to the end user.

Can confirm for 22w07a.

Can confirm in 22w11a. This is interesting, so I revisited the two locations shown in two earlier screenshots, and the grass on the floor seems to be no longer present, but the dirt block inside the house generates as a grass block instead. I set randomTickSpeed to be 0, so the grass block should never change into dirt. I think it's possible that in Avoma's image, the dirt block generated as a grass block, but converted to dirt due to his randomTickSpeed not being 0. Overall, it seems that this bug is "partially fixed", potentially fixed for grass, but not for terrain.

In 22w15a

This can also happen with leaves from trees generating inside of village houses, such as in 1.19 on seed 6325859001 at the coordinates of -1476, 95, -1960.
Can also confirm in 1.19; I found an example of this issue occurring with pillager outposts.
[media]Version: 1.19
Seed: 4373241205666815302
Coordinates: /execute in minecraft:overworld run tp @s -1291.42 102.00 -80357.28 610.24 7.06

1.19
seed:2275652456192416646
676 48 4272
random stone block in shipwreck
[media]
Shipwrecks have specific block spaces (mainly outside) set to void, so it keeps the old blocks. This is very different from what's described in this report.
Please create a separate issue for that, as that is a structure specific issue.

can confirm in 1.19, 1.19.1, 1.19.2, 1.19.3

Can confirm in 23w03a
Seed: 8587948038190963789
XYZ: -7987 97 1903
World type: Default
Image:
I've removed the part from this ticket about leaves from trees generating directly in front of village structures as that problem is tracked separately at MC-190031.

Can confirm in 1.21.4
Seed: -6533926018995126751
XYZ: -896 83 -1348
XYZ: 171 68 869

Can confirm in 1.21.4
seed: 4902607015186956457
-278 68 123
a hay bale in village's house
[media]The same seed
-255 71 80
There is a grass generated in the house, which is also the most common situation of this bug.

Affects 25w02a with the new leaf litter block:
Seed: -1311658802960653969
Position: /execute in minecraft:overworld run tp @s -1086.71 74.86 3481.74 -32.70 50.55