[0.17.79] Colliding cliff not marked for removal

[Khagan]

In the attached save, the hovering conbot can't place the rail, since the cliff immediately to the left is blocking it. But the cliff didn't get marked for removal when placing the track ghost (and still doesn't if I repeat the ghost placement).

This seems to be exactly the opposite problem from topic 78504.

screenshot-tick-7921822-cropped.png (511.89 KiB) Viewed 805 times