Fixes bubble/hull shield generators not updating air zones, update_nearby_tiles() cleanup.

code/modules/shieldgen/emergency_shield.dm

@@ -27,16 +27,6 @@
 	if(!height || air_group) return 0
 	else return ..()
 
-//Looks like copy/pasted code... I doubt 'need_rebuild' is even used here - Nodrak
-/obj/machinery/shield/proc/update_nearby_tiles(need_rebuild)
-	if(!air_master)
-		return 0
-
-	air_master.mark_for_update(get_turf(src))
-
-	return 1
-
-
 /obj/machinery/shield/attackby(obj/item/weapon/W as obj, mob/user as mob)
 	if(!istype(W)) return
 
@@ -357,4 +347,4 @@
 		src.icon_state = malfunction ? "shieldonbr":"shieldon"
 	else
 		src.icon_state = malfunction ? "shieldoffbr":"shieldoff"
-	return
+	return

code/modules/shieldgen/energy_field.dm

@@ -13,6 +13,14 @@
 	var/strength = 0
 	var/ticks_recovering = 10
 
+/obj/effect/energy_field/New()
+	..()
+	update_nearby_tiles()
+
+/obj/effect/energy_field/Del()
+	update_nearby_tiles()
+	..()
+
 /obj/effect/energy_field/ex_act(var/severity)
 	Stress(0.5 + severity)
 
@@ -44,12 +52,16 @@
 		strength = 0
 
 	//if we take too much damage, drop out - the generator will bring us back up if we have enough power
+	var/old_density = density
 	if(strength >= 1)
 		invisibility = 0
 		density = 1
 	else if(strength < 1)
 		invisibility = 101
 		density = 0
+	
+	if (density != old_density)
+		update_nearby_tiles()
 
 /obj/effect/energy_field/CanPass(atom/movable/mover, turf/target, height=1.5, air_group = 0)
 	//Purpose: Determines if the object (or airflow) can pass this atom.

code/modules/shieldgen/sheldwallgen.dm

@@ -242,6 +242,7 @@
 
 /obj/machinery/shieldwall/New(var/obj/machinery/shieldwallgen/A, var/obj/machinery/shieldwallgen/B)
 	..()
+	update_nearby_tiles()
 	src.gen_primary = A
 	src.gen_secondary = B
 	if(A && B && A.active && B.active)
@@ -253,6 +254,10 @@
 	else
 		del(src) //need at least two generator posts
 
+/obj/machinery/shieldwall/Del()
+	update_nearby_tiles()
+	..()
+
 /obj/machinery/shieldwall/attack_hand(mob/user as mob)
 	return
 
@@ -321,4 +326,4 @@
 		if (istype(mover, /obj/item/projectile))
 			return prob(10)
 		else
-			return !src.density
+			return !src.density