Some more overmap fixes (#2710)

nsv13/code/controllers/subsystem/starsystem.dm

@@ -296,7 +296,6 @@ Returns a faction datum by its name (case insensitive!)
 	return system
 
 /datum/controller/subsystem/star_system/proc/spawn_ship(obj/structure/overmap/OM, datum/star_system/target_sys, center=FALSE)//Select Ship to Spawn and Location via Z-Trait
-	target_sys.system_contents += OM
 	if(target_sys.occupying_z)
 		var/turf/destination = null
 		if(center)
@@ -689,12 +688,12 @@ Returns a faction datum by its name (case insensitive!)
 	START_PROCESSING(SSfastprocess, src)
 
 /obj/effect/overmap_anomaly/singularity/process()
-	if(!z) //Not in nullspace
+	if(!z || !current_system) //Not in nullspace
 		if(length(affecting))
 			for(var/obj/structure/overmap/OM in affecting)
 				stop_affecting(OM)
 		return
-	for(var/obj/structure/overmap/OM as() in GLOB.overmap_objects) //Has to go through global overmaps due to anomalies not referencing their system - probably something to change one day.
+	for(var/obj/structure/overmap/OM in current_system.system_contents) //This list is not exclusively overmaps so no as() calls.
 		if(LAZYFIND(affecting, OM))
 			continue
 		if(OM.z != z)

nsv13/code/modules/overmap/FTL/ftl_jump.dm

@@ -40,6 +40,9 @@
 	if(istype(OM, /obj/structure/overmap))
 		OM.current_system = src //Debugging purposes only
 		after_enter(OM)
+	else if(istype(OM, /obj/effect/overmap_anomaly))
+		var/obj/effect/overmap_anomaly/anomaly_OM = OM
+		anomaly_OM.current_system = src
 
 /datum/star_system/proc/after_enter(obj/structure/overmap/OM)
 	SEND_SIGNAL(src, COMSIG_STAR_SYSTEM_AFTER_ENTER, OM)

nsv13/code/modules/overmap/physics.dm

@@ -596,6 +596,10 @@ This proc is to be used when someone gets stuck in an overmap ship, gauss, WHATE
 	if(!z || QDELETED(src))
 		return FALSE
 	var/turf/T = get_center()
+	if(!T) //Might be at map edge.
+		T = get_turf(src)
+		if(!T) //Abort.
+			return FALSE
 	var/obj/item/projectile/proj = new proj_type(T)
 	if(ai_aim && !proj.can_home && !proj.hitscan)
 		target = calculate_intercept(target, proj, miss_chance=miss_chance, max_miss_distance=max_miss_distance)