[MC-77772] Mobs sink into blocks after falling with falling_block entity instead of landing on them

The bug

Mobs will sink into blocks instead of landing on them when falling with falling_block entities below them, unlike players that get pushed out.

How to reproduce

Build a sand or gravel tower
Spawn a mob on top of the tower
Remove one sand or gravel under the tower
→ ❌ The mob will sink into the block and on the second time will suffocate

Linked issues

is duplicated by 2

MC-106835 Mob goes inside the sand block with pistons sand and mob Resolved

MC-162643 Entities fall into gravity effected blocks Resolved

Attachments

MC-77772.mp4

Comments 17

Tomáš Misař 2015-02-22T06:22:00Z

Is there anyone with same problem?

Aaron Rhodes 2015-02-23T01:11:56Z

This might be caused by falling sand falling slower than mobs/players. The mob/player will land before the sand does, causing the mob/player to appear to sink into the sand.

KevinTheDruid 2016-10-07T17:01:18Z

I have this problem in 16w40a.
Place a 3x3 array of sand with a piston under the centre block.
Stand on the centre block.
When the piston activates for a short period (1 game tick, powered using observer block) the player ends up inside the sand block.

KevinTheDruid 2016-10-27T17:47:45Z

Confirmed for 16w43a

KevinTheDruid 2016-11-11T18:51:19Z

Confirmed for Minecraft 1.11 Pre-Release 1

7 more comments

Aaron Rhodes 2017-01-02T18:57:45Z

This is caused by the falling sand not becoming solid before the mob or player lands. What's happening is that the player is falling on a falling block entity, not on a solid sand block, and therefore goes through the block instead of landing on it. There is also the issue of the player or mob accelerating faster than falling block entities. This can be seen by placing a solid block high in the air with a sand block above it and a mob on the sand block. When you remove the solid block, you will see that the mob falls past the falling block. I'm not sure if there would be any issues or if it would be possible, but maybe giving falling blocks the same boundary effects as regular blocks would fix the problem. The issue seems to be an unintended side effect of an intended feature.