Mapgen: "Switch doesn't handle case f_null"

[mkrutov]

Describe the bug

Attach save file

Corryton_II.tar.gz

Steps to reproduce

1. load save
2. walk 10 steps left

Expected behavior

not erroring out

Screenshots

No response

Versions and configuration

• OS: Linux
  • OS Version: LSB Version: n/a; Distributor ID: openSUSE; Description: openSUSE Tumbleweed; Release: 20250929; Codename: n/a;
• Game Version: cdda-experimental-2025-11-03-1054 a5d2554 [64-bit]
• Graphics Version: Tiles
• Game Language: System language []
• Mods loaded: [
  Dark Days Ahead [dda],
  Disable NPC Needs [no_npc_food],
  Portal Storms Ignore NPCs [personal_portal_storms],
  Xedra Evolved [xedra_evolved],
  DinoMod [DinoMod],
  Bombastic Perks [bombastic_perks]
  ]

Additional context

No response