Correct non-pushing of partially destroyed doors

src/Dodge/Placement/Instance/Door.hs

@@ -13,7 +13,6 @@ import Dodge.LevelGen.Data
 import Dodge.Creature.Test
 import Dodge.LevelGen.Switch
 
-import Data.Maybe
 import Control.Lens
 import qualified Data.IntMap.Strict as IM
 
@@ -52,7 +51,7 @@ divideDoorPane mid pathing col cond soff speed ppairs g = case ppairs of
   where
     adoor (x,y) = PutSlideDr pathing col thedoor soff x y
     thedoor = defaultDoor & drSpeed .~ speed & drTrigger .~ cond
-        & drSupport .~ SupportedBy (fromJust mid)
+        & drSupport .~ maybe SupportsItself SupportedBy mid
 
 putAutoDoor :: Point2 -> Point2 -> Placement
 putAutoDoor a b = PlacementUsingPos (addZ 0 a)