correct behavior & use of QDEL_NULL_LIST+ odd shim

code/__defines/qdel.dm

@@ -26,8 +26,7 @@
 #define QDEL_IN(item, time) addtimer(CALLBACK(GLOBAL_PROC, .proc/qdel, item), time, TIMER_STOPPABLE)
 #define QDEL_IN_CLIENT_TIME(item, time) addtimer(CALLBACK(GLOBAL_PROC, .proc/qdel, item), time, TIMER_STOPPABLE | TIMER_CLIENT_TIME)
 #define QDEL_NULL(x) if(x) { qdel(x) ; x = null }
-#define QDEL_NULL_LIST QDEL_LIST_NULL
-#define QDEL_LIST_NULL(x) if(x) { for(var/y in x) { qdel(y) } ; x = null }
+#define QDEL_NULL_LIST(x) if (x) { for(var/y in x) { qdel(y) } }; if (x) { x.Cut(); x = null; }
 #define QDEL_LIST(L) if(L) { for(var/I in L) qdel(I); L.Cut(); }
 #define QDEL_LIST_IN(L, time) addtimer(CALLBACK(GLOBAL_PROC, .proc/______qdel_list_wrapper, L), time, TIMER_STOPPABLE)
 #define QDEL_LIST_ASSOC(L) if(L) { for(var/I in L) { qdel(L[I]); qdel(I); } L.Cut(); }

code/_onclick/hud/minihud.dm

@@ -12,7 +12,7 @@
 	unapply_to_hud()
 	if(needs_processing)
 		STOP_PROCESSING(SSprocessing, src)
-	QDEL_LIST_NULL(screenobjs)
+	QDEL_NULL_LIST(screenobjs)
 	return ..()
 
 // Apply to a real /datum/hud

code/game/objects/effects/temporary_visuals/projectiles/tracer.dm

@@ -2,7 +2,7 @@
 	var/list/beam_components = list()
 
 /datum/beam_components_cache/Destroy()
-	QDEL_LIST_NULL(beam_components)
+	QDEL_NULL_LIST(beam_components)
 	return ..()
 
 /proc/generate_tracer_between_points(datum/point/starting, datum/point/ending, datum/beam_components_cache/beam_components, beam_type, color, qdel_in = 5, light_range = 2, light_color_override, light_intensity = 1, instance_key)		//Do not pass z-crossing points as that will not be properly (and likely will never be properly until it's absolutely needed) supported!

code/game/objects/items/weapons/grenades/chem_grenade.dm

@@ -21,7 +21,7 @@
 
 /obj/item/grenade/chem_grenade/Destroy()
 	QDEL_NULL(detonator)
-	QDEL_LIST_NULL(beakers)
+	QDEL_NULL_LIST(beakers)
 	return ..()
 
 /obj/item/grenade/chem_grenade/attack_self(mob/user as mob)

code/modules/assembly/infrared.dm

@@ -39,7 +39,7 @@
 		START_PROCESSING(SSobj, src)
 	else
 		STOP_PROCESSING(SSobj, src)
-		QDEL_LIST_NULL(i_beams)
+		QDEL_NULL_LIST(i_beams)
 	return on
 
 /obj/item/assembly/infra/update_icon()
@@ -54,7 +54,7 @@
 
 /obj/item/assembly/infra/process()
 	if(!on && i_beams)
-		QDEL_LIST_NULL(i_beams)
+		QDEL_NULL_LIST(i_beams)
 		return
 
 	if(!i_beams && secured && (istype(loc, /turf) || (holder && istype(holder.loc, /turf))))
@@ -74,7 +74,7 @@
 		I.visible = visible
 
 /obj/item/assembly/infra/attack_hand()
-	QDEL_LIST_NULL(i_beams)
+	QDEL_NULL_LIST(i_beams)
 	..()
 
 /obj/item/assembly/infra/Move()
@@ -84,19 +84,19 @@
 
 /obj/item/assembly/infra/Moved(atom/old_loc, direction, forced = FALSE)
 	. = ..()
-	QDEL_LIST_NULL(i_beams)
+	QDEL_NULL_LIST(i_beams)
 
 /obj/item/assembly/infra/holder_movement()
 	if(!holder)
 		return FALSE
-	QDEL_LIST_NULL(i_beams)
+	QDEL_NULL_LIST(i_beams)
 	return TRUE
 
 /obj/item/assembly/infra/proc/trigger_beam()
 	if(!process_cooldown())
 		return FALSE
 	pulse(0)
-	QDEL_LIST_NULL(i_beams) //They will get recreated next process() if the situation is still appropriate
+	QDEL_NULL_LIST(i_beams) //They will get recreated next process() if the situation is still appropriate
 	if(!holder)
 		visible_message("[bicon(src)] *beep* *beep*")
 

code/modules/mob/mob_planes.dm

@@ -50,7 +50,7 @@
 
 /datum/plane_holder/Destroy()
 	my_mob = null
-	QDEL_LIST_NULL(plane_masters) //Goodbye my children, be free
+	QDEL_NULL_LIST(plane_masters) //Goodbye my children, be free
 	return ..()
 
 /datum/plane_holder/proc/set_vis(var/which = null, var/state = FALSE)

code/modules/shieldgen/shield_gen.dm

@@ -44,7 +44,7 @@
 	return ..()
 
 /obj/machinery/shield_gen/Destroy()
-	QDEL_LIST_NULL(field)
+	QDEL_NULL_LIST(field)
 	return ..()
 
 /obj/machinery/shield_gen/emag_act(var/remaining_charges, var/mob/user)