Bug: Deleting areas randomly reverts other areas to how they were before.

[ClownMoff]

Version

2.16 Alpha

What happened?

When deleting areas, it randomly reverts a lot of the work you had done in the area to how it was before. This is the second time something like this has happened to me, first one was pretty minor and it just removed not a lot of work but look at what it just did.

As you can see in the video, Control+Z only filled the thing with empty space rather than to bring everything back.

0513.mp4

Reproduction

1. Run StrongDMM
2. In an specific z-level, delete an area

Relevant log output