Too remove potential excessive garbage collection per tick. We will be reusing lists for overlays instead of deleting and creating them.

the .Cut() proc on a list will empty a list by default. This also will set the len to 0.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@5465 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/objects/items/bodybag.dm

@@ -61,7 +61,7 @@
 		else if(istype(W, /obj/item/weapon/wirecutters))
 			user << "You cut the tag off the bodybag"
 			src.name = "body bag"
-			src.overlays = null
+			src.overlays.Cut()
 			return
 
 

code/game/objects/items/devices/PDA/PDA.dm

@@ -682,7 +682,7 @@ var/global/list/obj/item/device/pda/PDAs = list()
 //EXTRA FUNCTIONS===================================
 
 	if (mode == 2||mode == 21)//To clear message overlays.
-		overlays = null
+		overlays.Cut()
 
 	if ((honkamt > 0) && (prob(60)))//For clown virus.
 		honkamt--
@@ -781,7 +781,7 @@ var/global/list/obj/item/device/pda/PDAs = list()
 			L << "\icon[P] <b>Message from [src.owner] ([ownjob]), </b>\"[t]\" (<a href='byond://?src=\ref[P];choice=Message;skiprefresh=1;target=\ref[src]'>Reply</a>)"
 
 		log_pda("[usr] (PDA: [src.name]) sent \"[t]\" to [P.name]")
-		P.overlays = null
+		P.overlays.Cut()
 		P.overlays += image('icons/obj/pda.dmi', "pda-r")
 	else
 		U << "<span class='notice'>ERROR: Server isn't responding.</span>"

code/game/objects/items/devices/paicard.dm

@@ -110,12 +110,12 @@
 
 /obj/item/device/paicard/proc/removePersonality()
 	src.pai = null
-	src.overlays = null
+	src.overlays.Cut()
 	src.overlays += "pai-off"
 
 /obj/item/device/paicard/proc/setEmotion(var/emotion)
 	if(pai)
-		src.overlays = null
+		src.overlays.Cut()
 		switch(emotion)
 			if(1) src.overlays += "pai-happy"
 			if(2) src.overlays += "pai-cat"

code/game/objects/items/devices/transfer_valve.dm

@@ -115,7 +115,7 @@
 			toggle = 1
 
 /obj/item/device/transfer_valve/update_icon()
-	overlays = null
+	overlays.Cut()
 	underlays = null
 
 	if(!tank_one && !tank_two && !attached_device)

code/game/objects/items/robot/robot_parts.dm

@@ -73,7 +73,7 @@
 	src.updateicon()
 
 /obj/item/robot_parts/robot_suit/proc/updateicon()
-	src.overlays = null
+	src.overlays.Cut()
 	if(src.l_arm)
 		src.overlays += "l_arm+o"
 	if(src.r_arm)

code/game/objects/items/shooting_range.dm

@@ -36,7 +36,7 @@
 		if (istype(W, /obj/item/weapon/weldingtool))
 			var/obj/item/weapon/weldingtool/WT = W
 			if(WT.remove_fuel(0, user))
-				overlays = null
+				overlays.Cut()
 				usr << "You slice off [src]'s uneven chunks of aluminum and scorch marks."
 				return
 

code/game/objects/items/tk_grab.dm

@@ -97,7 +97,7 @@
 
 
 	update_icon()
-		overlays = null
+		overlays.Cut()
 		if(focus && focus.icon && focus.icon_state)
 			overlays += icon(focus.icon,focus.icon_state)
 		return

code/game/objects/items/weapons/flamethrower.dm

@@ -48,7 +48,7 @@
 
 
 /obj/item/weapon/flamethrower/update_icon()
-	overlays = null
+	overlays.Cut()
 	if(igniter)
 		overlays += "+igniter[status]"
 	if(ptank)

code/game/objects/items/weapons/kitchen.dm

@@ -222,7 +222,7 @@
 /obj/item/weapon/tray/attack(mob/living/carbon/M as mob, mob/living/carbon/user as mob)
 
 	// Drop all the things. All of them.
-	overlays = null
+	overlays.Cut()
 	for(var/obj/item/I in carrying)
 		I.loc = M.loc
 		carrying.Remove(I)
@@ -391,7 +391,7 @@
 		foundtable = 1
 		break
 
-	overlays = null
+	overlays.Cut()
 
 	for(var/obj/item/I in carrying)
 		I.loc = loc

code/game/objects/items/weapons/secstorage/secstorage.dm

@@ -106,7 +106,7 @@
 		emagged = 1
 		src.overlays += image('icons/obj/storage.dmi', icon_sparking)
 		sleep(6)
-		src.overlays = null
+		src.overlays.Cut()
 		overlays += image('icons/obj/storage.dmi', icon_locking)
 		locked = 0
 		if(istype(W, /obj/item/weapon/melee/energy/blade))
@@ -225,7 +225,7 @@
 				src.l_set = 1
 			else if ((src.code == src.l_code) && (src.emagged == 0) && (src.l_set == 1))
 				src.locked = 0
-				src.overlays = null
+				src.overlays.Cut()
 				overlays += image('icons/obj/storage.dmi', icon_opened)
 				src.code = null
 			else
@@ -233,7 +233,7 @@
 		else
 			if ((href_list["type"] == "R") && (src.emagged == 0) && (!src.l_setshort))
 				src.locked = 1
-				src.overlays = null
+				src.overlays.Cut()
 				src.code = null
 				src.close(usr)
 			else