Fixes tiny door zones

Fixes #8987 by deferring the update of self-zone-blocked turfs until after non-self-zone-block turfs have updated (and thus have valid zones).

code/ZAS/Controller.dm

@@ -154,7 +154,18 @@ Total Unsimulated Turfs: [world.maxx*world.maxy*world.maxz - simulated_turf_coun
 		#ifdef ZASDBG
 		var/updated = 0
 		#endif
+		
+		//defer updating of self-zone-blocked turfs until after all other turfs have been updated.
+		//this hopefully ensures that non-self-zone-blocked turfs adjacent to self-zone-blocked ones
+		//have valid zones when the self-zone-blocked turfs update.
+		var/list/deferred = list()
+		
 		for(var/turf/T in updating)
+			//check if the turf is self-zone-blocked
+			if(T.c_airblock(T) & ZONE_BLOCKED)
+				deferred += T
+				continue
+			
 			T.update_air_properties()
 			T.post_update_air_properties()
 			T.needs_air_update = 0
@@ -164,6 +175,15 @@ Total Unsimulated Turfs: [world.maxx*world.maxy*world.maxz - simulated_turf_coun
 			#endif
 			//sleep(1)
 
+		for(var/turf/T in deferred)
+			T.update_air_properties()
+			T.post_update_air_properties()
+			T.needs_air_update = 0
+			#ifdef ZASDBG
+			T.overlays -= mark
+			updated++
+			#endif
+
 		#ifdef ZASDBG
 		if(updated != updating.len)
 			tick_progress = "[updating.len - updated] tiles left unupdated."
@@ -307,7 +327,7 @@ Total Unsimulated Turfs: [world.maxx*world.maxy*world.maxz - simulated_turf_coun
 
 /datum/controller/air_system/proc/mark_edge_sleeping(connection_edge/E)
 	#ifdef ZASDBG
-	ASSERT(istype(E)
+	ASSERT(istype(E))
 	#endif
 	if(E.sleeping) return
 	active_edges.Remove(E)
@@ -315,7 +335,7 @@ Total Unsimulated Turfs: [world.maxx*world.maxy*world.maxz - simulated_turf_coun
 
 /datum/controller/air_system/proc/mark_edge_active(connection_edge/E)
 	#ifdef ZASDBG
-	ASSERT(istype(E)
+	ASSERT(istype(E))
 	#endif
 	if(!E.sleeping) return
 	active_edges.Add(E)