Merge pull request #2550

code/modules/mapping/mapping_helpers.dm

@@ -49,3 +49,21 @@
 /obj/effect/baseturf_helper/lava_land/surface
 	name = "lavaland baseturf editor"
 	baseturf = /turf/open/lava/smooth/lava_land_surface
+
+
+//Contains the list of planetary z-levels defined by the planet_z helper.
+GLOBAL_LIST_EMPTY(z_is_planet)
+
+/obj/effect/mapping_helpers/planet_z //adds the map it is on to the z_is_planet list
+	name = "planet z helper"
+	icon = 'icons/obj/items_and_weapons.dmi'
+	icon_state = "syndballoon"
+	layer = POINT_LAYER
+
+/obj/effect/mapping_helpers/planet_z/Initialize()
+	. = ..()
+	var/turf/T = get_turf(src)
+	if(!turf_z_is_planet(T))
+		GLOB.z_is_planet["[T.z]"] = list()
+	qdel(src)
+