turns the baseturf var into a part time list (#33705)

code/modules/mapping/mapping_helpers.dm

@@ -13,11 +13,15 @@
 	. = ..()
 	var/area/thearea = get_area(src)
 	for(var/turf/T in get_area_turfs(thearea, z))
-		if(T.baseturf != T.type) //Don't break indestructible walls and the like
-			T.baseturf = baseturf
+		if(T.baseturfs != T.type) //Don't break indestructible walls and the like
+			T.baseturfs = baseturf
 	return INITIALIZE_HINT_QDEL
 
 
+/obj/effect/baseturf_helper/space
+	name = "space baseturf editor"
+	baseturf = /turf/open/space
+
 /obj/effect/baseturf_helper/asteroid
 	name = "asteroid baseturf editor"
 	baseturf = /turf/open/floor/plating/asteroid