Pre 1.14: Terrain inside villager hut

This report is for the old villages before the 1.14 snapshots. See MC-140727 for the same bug with the new 1.14(+) villages.

The bug

Grass can generate inside a villager house. That doesn't seem right.

How to reproduce

This can be in general seen pretty good with a Superflat world filled with water:

minecraft:stone,90*minecraft:water;minecraft:plains;village

Seed: 888005577202285872
/tp @s 629 65 245604 70 10

Seed: -5502958542695102104 (amplified terrain generation)
/tp @s -2890 88 1220 90 10

Affected village parts

might be incomplete

Large L-shaped house

• Row in room, see for example 2013-07-08_09.53.21.png
• 1 × 6 line below top of roof

Small 4 × 4 house without door

Blocks in entrance

Well

Blocks between roof and well

Lanterns (torches on wool)

Only 2 × 3 area instead of 3 × 3 filled with air

Church

Blocks next to torches in bottom floor

4 × 5 house

Possibly too many blocks replaced with air:
Blocks on roof are replaced in L-shape instead of all or none