Merge remote-tracking branch 'upstream/master' into hopefullythefinalhardsync

code/game/turfs/change_turf.dm

@@ -114,6 +114,23 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 
 	return W
 
+/turf/open/ChangeTurf(path, list/new_baseturfs, flags)
+	if ((flags & CHANGETURF_INHERIT_AIR) && ispath(path, /turf/open))
+		SSair.remove_from_active(src)
+		var/stashed_air = air
+		air = null // so that it doesn't get deleted
+		. = ..()
+		if (!. || . == src) // changeturf failed or didn't do anything
+			air = stashed_air
+			return
+		var/turf/open/newTurf = .
+		if (!istype(newTurf.air, /datum/gas_mixture/immutable/space))
+			QDEL_NULL(newTurf.air)
+			newTurf.air = stashed_air
+		SSair.add_to_active(newTurf)
+	else
+		return ..()
+
 // Take off the top layer turf and replace it with the next baseturf down
 /turf/proc/ScrapeAway(amount=1, flags)
 	if(!amount)
@@ -251,7 +268,7 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 /turf/open/AfterChange(flags)
 	..()
 	RemoveLattice()
-	if(!(flags & CHANGETURF_IGNORE_AIR))
+	if(!(flags & (CHANGETURF_IGNORE_AIR | CHANGETURF_INHERIT_AIR)))
 		Assimilate_Air()
 
 //////Assimilate Air//////
@@ -284,4 +301,4 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 
 /turf/proc/ReplaceWithLattice()
 	ScrapeAway()
-	new /obj/structure/lattice(locate(x, y, z))
+	new /obj/structure/lattice(locate(x, y, z))