Regression bug noticed in 0.18.21:
1. stand on solid ground adjacent to void (no tiles)
2. place different terrain down under you such as brick, concrete, refined concrete
3. (bug, shown above): the void expands. walk onto the new landfill area and pick up the brick you placed above, on the place you came from and immediately fill that tile again:
4. repeat 1-3
5. additionally, spamming left and right mouse button while holding the mouse in a stable position can repeat this action very rapidly resulting in cheating in mods that depend on void for permanent generated collision blocking, and ruining the player experience: