Placing blocks may drop the player underground

[SodiumZH]

I was fixing a creeper pit and found the player very likely to drop inside the ground surface, especially when placing a dirt block closely to the player itself.
When dropped underground, it will be difficult to escape by myself. Trying digging upside will dramatically make me drop deeper.

Seemingly collision detection of the flatened ground surface encountered some issues. When a player is stuck partly into the surface due to the surface change on the player's position (caused by a close block-placing), the player lose its collision onto the surface planes and detects nothing below its feet. The figure below is my guess:

[SodiumZH]

I removed NoCube and checked the ground, finding there wasn't any hole on the ground (after escaping from the solid blocks).
I'm not sure if sand falling is another cause of this issue...

[Cadiboo]

Is this on 1.19?

[SodiumZH]

Is this on 1.19?

It's on 1.12.2. For higher versions I did't test.

[SodiumZH]

To reproduce this issue:

1. In survival mode, ignite a TNT on the ground to make a pit;
2. Try fixing it with dirt blocks with the player standing inside or around the pit.

[Cadiboo]

I believe this has been fixed in newer versions (1.16.5 onwards)

[Cadiboo]

I am planning to backport fixes from 1.16.5+ to 1.12.2 some time in future but currently there is no roadmap for this.