[MIRROR] Transit space refactor (#7130)

* Transit space refactor

* Update bitfields.dm

code/modules/shuttle/docking.dm

@@ -16,7 +16,7 @@
 
 	// The area that gets placed under where the shuttle moved from
 	var/underlying_area_type = SHUTTLE_DEFAULT_UNDERLYING_AREA
-	
+
 	if(old_dock) //Dock overwrites
 		underlying_area_type = old_dock.area_type
 
@@ -105,7 +105,7 @@
 	list/areas_to_move,
 	rotation,
 	)
-	
+
 	for(var/i in 1 to old_turfs.len)
 		CHECK_TICK
 		var/turf/oldT = old_turfs[i]
@@ -173,7 +173,7 @@
 	movement_direction,
 	area/underlying_old_area,
 	)
-	
+
 	underlying_old_area.afterShuttleMove()
 
 	// Parallax handling

code/modules/shuttle/shuttle.dm

@@ -202,7 +202,7 @@
 
 /obj/docking_port/stationary/transit
 	name = "In Transit"
-	var/list/turf/assigned_turfs = list()
+	var/datum/turf_reservation/reserved_area
 	var/area/shuttle/transit/assigned_area
 	var/obj/docking_port/mobile/owner
 
@@ -210,14 +210,6 @@
 	. = ..()
 	SSshuttle.transit += src
 
-/obj/docking_port/stationary/transit/proc/dezone()
-	for(var/i in 1 to assigned_turfs.len)
-		var/turf/T = assigned_turfs[i]
-		if(istype(T, /turf/open/space/transit))
-			T.ChangeTurf(/turf/open/space)
-			T.assemble_baseturfs(initial(T.baseturfs))
-			T.flags_1 |= UNUSED_TRANSIT_TURF_1
-
 /obj/docking_port/stationary/transit/Destroy(force=FALSE)
 	if(force)
 		if(get_docked())
@@ -227,11 +219,10 @@
 			if(owner.assigned_transit == src)
 				owner.assigned_transit = null
 			owner = null
-		if(assigned_turfs)
-			dezone()
-			assigned_turfs.Cut()
-		assigned_turfs = null
-	. = ..()
+		if(!QDELETED(reserved_area))
+			qdel(reserved_area)
+		reserved_area = null
+	return ..()
 
 /obj/docking_port/mobile
 	name = "shuttle"
@@ -282,7 +273,7 @@
 		SSshuttle.mobile -= src
 		destination = null
 		previous = null
-		assigned_transit = null
+		QDEL_NULL(assigned_transit)		//don't need it where we're goin'!
 		shuttle_areas = null
 		remove_ripples()
 	. = ..()
@@ -433,7 +424,7 @@
 		underlying_area_type = current_dock.area_type
 
 	var/list/old_turfs = return_ordered_turfs(x, y, z, dir)
-	
+
 	var/area/underlying_area
 	for(var/i in GLOB.sortedAreas)
 		var/area/place = i
@@ -451,7 +442,7 @@
 		underlying_area.contents += oldT
 		oldT.change_area(old_area, underlying_area)
 		oldT.empty(FALSE)
-		
+
 		// Here we locate the bottomost shuttle boundary and remove all turfs above it
 		var/list/baseturf_cache = oldT.baseturfs
 		for(var/k in 1 to length(baseturf_cache))