Random field areas with overmap terrain type "nothing" instead of "field"

[i2amroy]

As can be seen in the image above. Appears to function identically to a normal field except for it's type. Possibly related to problems #437 and #426.

[KA101]

Huh. I wonder if that's consistent? I've certainly been in "nothing" areas without encountering worms, but that could be a spawning-artifact.

[i2amroy]

I'm working on checking consistency right now, but am having difficulty tracking down another worm spawn area. Once I find some more results I'll post here with the news.

Ok, turns out it's not related to worm groups. I'll update the original issue report to reflect that.

[VaniBA]

Also while in this "nothing" area, your position is not showed on Map (no blinking @).

[fergus-dall]

Playing around in debug mode, this seems to happen within 5 submaps (2.5 overmap tiles) of an overmap boarder, though usually only on one side of the boarder. I can't find much consistency in which side of the boarder it occurs on.

[fergus-dall]

This is still broken in bbbdab5. Steps to replicate:

1. Reveal the overmap
2. Debug-teleport to the north-most edge of the overmap
3. Move one overmap tile east, west or south (not north)