Convert turfs to use add_overlays(), eliminating the turf_overlay_holder!

- Converted as much as I could find about turf overlays to use add_overlay().
- This should be enough to stop BYOND from crashing, so we can eliminate the turf_overlay_holder hack.
- This also lets us remove the anti-corruption hacks from walls and open space.
- ZAS gas overlays can use priority overlays, so this also fixes the gas-goes-away-when-crowbarring-plating issue.
- Stuff like that

code/ZAS/Turf.dm

@@ -6,9 +6,9 @@
 
 /turf/simulated/proc/update_graphic(list/graphic_add = null, list/graphic_remove = null)
 	if(LAZYLEN(graphic_add))
-		overlays += graphic_add
+		add_overlay(graphic_add, priority = TRUE)
 	if(LAZYLEN(graphic_remove))
-		overlays -= graphic_remove
+		cut_overlay(graphic_remove, priority = TRUE)
 
 /turf/proc/update_air_properties()
 	var/block = c_airblock(src)

code/_helpers/unsorted.dm

@@ -800,7 +800,6 @@ proc/GaussRandRound(var/sigma,var/roundto)
 						var/old_dir1 = T.dir
 						var/old_icon_state1 = T.icon_state
 						var/old_icon1 = T.icon
-						var/old_overlays = T.overlays.Copy()
 						var/old_underlays = T.underlays.Copy()
 						var/old_decals = T.decals ? T.decals.Copy() : null
 
@@ -808,11 +807,9 @@ proc/GaussRandRound(var/sigma,var/roundto)
 						X.set_dir(old_dir1)
 						X.icon_state = old_icon_state1
 						X.icon = old_icon1
-						X.overlays = old_overlays
+						X.copy_overlays(T, TRUE)
 						X.underlays = old_underlays
 						X.decals = old_decals
-						if(old_decals)
-							X.apply_decals()
 
 					//Move the air from source to dest
 					var/turf/simulated/ST = T
@@ -838,14 +835,10 @@ proc/GaussRandRound(var/sigma,var/roundto)
 					if(shuttlework)
 						var/turf/simulated/shuttle/SS = T
 						SS.landed_holder.leave_turf()
-
 					else if(turftoleave)
 						T.ChangeTurf(turftoleave)
-						T.apply_decals()
-
 					else
 						T.ChangeTurf(get_base_turf_by_area(T))
-						T.apply_decals()
 
 					refined_src -= T
 					refined_trg -= B

code/controllers/subsystems/floor_decals.dm

@@ -1,28 +0,0 @@
-//
-// Floor Decals Initialization Subsystem
-// This is part of the giant decal hack that works around a BYOND bug where DreamDaemon will crash if you
-// update overlays on turfs too much.
-// The master_controller on Polaris used to init decals prior to initializing areas (which initilized turfs)
-// Now that we switched to subsystems we still want to do the same thing, so this takes care of it.
-//
-SUBSYSTEM_DEF(floor_decals)
-	name = "Floor Decals"
-	init_order = INIT_ORDER_DECALS
-	flags = SS_NO_FIRE
-
-/datum/controller/subsystem/floor_decals/Initialize(timeofday)
-	if(floor_decals_initialized)
-		return ..()
-	to_world_log("Initializing Floor Decals")
-	admin_notice("<span class='danger'>Initializing Floor Decals</span>", R_DEBUG)
-	var/list/turfs_with_decals = list()
-	for(var/obj/effect/floor_decal/D in world)
-		var/T = D.add_to_turf_decals()
-		if(T) turfs_with_decals |= T
-		CHECK_TICK
-	for(var/item in turfs_with_decals)
-		var/turf/T = item
-		if(T.decals) T.apply_decals()
-		CHECK_TICK
-	floor_decals_initialized = TRUE
-	return ..()

code/game/turfs/flooring/flooring_decals.dm

@@ -14,17 +14,29 @@ var/list/floor_decals = list()
 	if(newcolour) color = newcolour
 	..(newloc)
 
-// Hack to workaround byond crash bug
 /obj/effect/floor_decal/initialize()
-	if(!floor_decals_initialized || !loc || QDELETED(src))
-		return
 	add_to_turf_decals()
-	var/turf/T = get_turf(src)
-	if(T) //VOREStation Edit
-		T.apply_decals()
 	initialized = TRUE
 	return INITIALIZE_HINT_QDEL
 
+// This is a separate proc from initialize() to facilitiate its caching and other stuff.  Look into it someday.
+/obj/effect/floor_decal/proc/add_to_turf_decals()
+	if(supplied_dir)
+		set_dir(supplied_dir) // TODO - Why can't this line be done in initialize/New()?
+	var/turf/T = get_turf(src)
+	if(istype(T, /turf/simulated/floor) || istype(T, /turf/unsimulated/floor) || istype(T, /turf/simulated/shuttle/floor))
+		var/cache_key = "[alpha]-[color]-[dir]-[icon_state]-[T.layer]"
+		var/image/I = floor_decals[cache_key]
+		if(!I)
+			I = image(icon = icon, icon_state = icon_state, dir = dir)
+			I.layer = T.layer
+			I.color = color
+			I.alpha = alpha
+			floor_decals[cache_key] = I
+		LAZYADD(T.decals, I) // Add to its decals list (so it remembers to re-apply after it cuts overlays)
+		T.add_overlay(I) // Add to its current overlays too.
+		return T
+
 /obj/effect/floor_decal/reset
 	name = "reset marker"
 

code/game/turfs/flooring/flooring_premade.dm

@@ -230,9 +230,8 @@
 	oxygen = 0
 	nitrogen = 0
 
-/turf/simulated/floor/reinforced/n20/New()
+/turf/simulated/floor/reinforced/n20/initialize()
-	..()
+	. = ..()
-	sleep(-1)
 	if(!air) make_air()
 	air.adjust_gas("sleeping_agent", ATMOSTANK_NITROUSOXIDE)
 
@@ -411,11 +410,11 @@
     . = ..()
 
 /turf/snow/update_icon()
-    overlays.Cut()
+    cut_overlays()
     for(var/d in crossed_dirs)
         var/amt = crossed_dirs[d]
 
         for(var/i in 1 to amt)
-            overlays += icon(icon, "footprint[i]", text2num(d))
+            add_overlay(image(icon, "footprint[i]", text2num(d)))
 
 //**** Here ends snow ****

code/game/turfs/flooring/turf_overlay_holder.dm

@@ -1,95 +0,0 @@
-//
-// Initialize floor decals!	 Woo! This is crazy.
-//
-
-var/global/floor_decals_initialized = FALSE
-
-// The Turf Decal Holder
-// Since it is unsafe to add overlays to turfs, we hold them here for now.
-// Since I want this object to basically not exist, I am modeling it in part after lighting_overlay
-/atom/movable/turf_overlay_holder
-	name = "turf overlay holder"
-	density = 0
-	simulated = 0
-	anchored = 1
-	layer = TURF_LAYER
-	icon = null
-	icon_state = null
-	mouse_opacity = 0
-	// auto_init = 0
-
-/atom/movable/turf_overlay_holder/initialize()
-	// doesn't need special init
-	initialized = TRUE
-	return INITIALIZE_HINT_NORMAL
-
-/atom/movable/turf_overlay_holder/New(var/atom/newloc)
-	..()
-	verbs.Cut()
-	var/turf/T = loc
-	T.overlay_holder = src
-
-/atom/movable/turf_overlay_holder/Destroy()
-	if(loc)
-		var/turf/T = loc
-		if(T.overlay_holder == src)
-			T.overlay_holder = null
-	. = ..()
-
-// Variety of overrides so the overlays don't get affected by weird things.
-/atom/movable/turf_overlay_holder/ex_act()
-	return
-
-/atom/movable/turf_overlay_holder/singularity_act()
-	return
-
-/atom/movable/turf_overlay_holder/singularity_pull()
-	return
-
-/atom/movable/turf_overlay_holder/forceMove()
-	return 0 //should never move
-
-/atom/movable/turf_overlay_holder/Move()
-	return 0
-
-/atom/movable/turf_overlay_holder/throw_at()
-	return 0
-
-/obj/effect/floor_decal/proc/add_to_turf_decals()
-	if(src.supplied_dir) src.set_dir(src.supplied_dir)
-	var/turf/T = get_turf(src)
-	if(istype(T, /turf/simulated/floor) || istype(T, /turf/unsimulated/floor) || istype(T, /turf/simulated/shuttle/floor))
-		var/cache_key = "[src.alpha]-[src.color]-[src.dir]-[src.icon_state]-[T.layer]"
-		var/image/I = floor_decals[cache_key]
-		if(!I)
-			I = image(icon = src.icon, icon_state = src.icon_state, dir = src.dir)
-			I.layer = T.layer
-			I.color = src.color
-			I.alpha = src.alpha
-			floor_decals[cache_key] = I
-		if(!T.decals) T.decals = list()
-		//world.log << "About to add img:\ref[I] onto decals at turf:\ref[T] ([T.x],[T.y],[T.z]) which has appearance:\ref[T.appearance] and decals.len=[T.decals.len]"
-		T.decals += I
-		return T
-	// qdel(D)
-	src.loc = null
-	src.tag = null
-
-// Changes to turf to let us do this
-/turf
-	var/atom/movable/turf_overlay_holder/overlay_holder = null
-
-// After a turf change, destroy the old overlay holder since we will have lost access to it.
-/turf/post_change()
-	var/atom/movable/turf_overlay_holder/TOH = locate(/atom/movable/turf_overlay_holder, src)
-	if(TOH)
-		qdel(TOH)
-	..()
-
-/turf/proc/apply_decals()
-	if(decals)
-		if(!overlay_holder)
-			overlay_holder = new(src)
-		overlay_holder.overlays = src.decals
-	else if(overlay_holder)
-		overlay_holder.overlays.Cut()

code/game/turfs/simulated.dm

@@ -21,16 +21,15 @@
 	spawn(0)
 		wet = wet_val
 		if(wet_overlay)
-			overlays -= wet_overlay
+			cut_overlay(wet_overlay)
-			wet_overlay = null
+		wet_overlay = image('icons/effects/water.dmi', icon_state = "wet_floor")
-		wet_overlay = image('icons/effects/water.dmi',src,"wet_floor")
+		add_overlay(wet_overlay)
-		overlays += wet_overlay
 		sleep(800)
 		if(wet == 2)
 			sleep(3200)
 		wet = 0
 		if(wet_overlay)
-			overlays -= wet_overlay
+			cut_overlay(wet_overlay)
 			wet_overlay = null
 
 /turf/simulated/proc/freeze_floor()
@@ -38,14 +37,14 @@
 		return
 	wet = 3 // icy
 	if(wet_overlay)
-		overlays -= wet_overlay
+		cut_overlay(wet_overlay)
 		wet_overlay = null
 	wet_overlay = image('icons/turf/overlays.dmi',src,"snowfloor")
-	overlays += wet_overlay
+	add_overlay(wet_overlay)
 	spawn(5 MINUTES)
 		wet = 0
 		if(wet_overlay)
-			overlays -= wet_overlay
+			cut_overlay(wet_overlay)
 			wet_overlay = null
 
 /turf/simulated/clean_blood()

code/game/turfs/simulated/floor.dm

@@ -60,7 +60,7 @@
 //This proc auto corrects the grass tiles' siding.
 /turf/simulated/floor/proc/make_plating(var/place_product, var/defer_icon_update)
 
-	overlays.Cut()
+	cut_overlays()
 	// VOREStation Edit - We are flooring switching to plating, swap out old_decals for decals.
 	if(flooring)
 		var/tmp/list/underfloor_decals = old_decals

code/game/turfs/simulated/floor_icon.dm

@@ -15,7 +15,7 @@ var/image/no_ceiling_image = null
 	if(lava)
 		return
 
-	overlays.Cut()
+	cut_overlays()
 
 	if(flooring)
 		// Set initial icon and strings.
@@ -38,17 +38,17 @@ var/image/no_ceiling_image = null
 				var/turf/simulated/floor/T = get_step(src, step_dir)
 				if(!istype(T) || !T.flooring || T.flooring.name != flooring.name)
 					has_border |= step_dir
-					overlays |= get_flooring_overlay("[flooring.icon_base]-edge-[step_dir]", "[flooring.icon_base]_edges", step_dir)
+					add_overlay(get_flooring_overlay("[flooring.icon_base]-edge-[step_dir]", "[flooring.icon_base]_edges", step_dir))
 
 			// There has to be a concise numerical way to do this but I am too noob.
 			if((has_border & NORTH) && (has_border & EAST))
-				overlays |= get_flooring_overlay("[flooring.icon_base]-edge-[NORTHEAST]", "[flooring.icon_base]_edges", NORTHEAST)
+				add_overlay(get_flooring_overlay("[flooring.icon_base]-edge-[NORTHEAST]", "[flooring.icon_base]_edges", NORTHEAST))
 			if((has_border & NORTH) && (has_border & WEST))
-				overlays |= get_flooring_overlay("[flooring.icon_base]-edge-[NORTHWEST]", "[flooring.icon_base]_edges", NORTHWEST)
+				add_overlay(get_flooring_overlay("[flooring.icon_base]-edge-[NORTHWEST]", "[flooring.icon_base]_edges", NORTHWEST))
 			if((has_border & SOUTH) && (has_border & EAST))
-				overlays |= get_flooring_overlay("[flooring.icon_base]-edge-[SOUTHEAST]", "[flooring.icon_base]_edges", SOUTHEAST)
+				add_overlay(get_flooring_overlay("[flooring.icon_base]-edge-[SOUTHEAST]", "[flooring.icon_base]_edges", SOUTHEAST))
 			if((has_border & SOUTH) && (has_border & WEST))
-				overlays |= get_flooring_overlay("[flooring.icon_base]-edge-[SOUTHWEST]", "[flooring.icon_base]_edges", SOUTHWEST)
+				add_overlay(get_flooring_overlay("[flooring.icon_base]-edge-[SOUTHWEST]", "[flooring.icon_base]_edges", SOUTHWEST))
 
 			if(flooring.flags & TURF_HAS_CORNERS)
 				// As above re: concise numerical way to do this.
@@ -56,37 +56,36 @@ var/image/no_ceiling_image = null
 					if(!(has_border & EAST))
 						var/turf/simulated/floor/T = get_step(src, NORTHEAST)
 						if(!(istype(T) && T.flooring && T.flooring.name == flooring.name))
-							overlays |= get_flooring_overlay("[flooring.icon_base]-corner-[NORTHEAST]", "[flooring.icon_base]_corners", NORTHEAST)
+							add_overlay(get_flooring_overlay("[flooring.icon_base]-corner-[NORTHEAST]", "[flooring.icon_base]_corners", NORTHEAST))
 					if(!(has_border & WEST))
 						var/turf/simulated/floor/T = get_step(src, NORTHWEST)
 						if(!(istype(T) && T.flooring && T.flooring.name == flooring.name))
-							overlays |= get_flooring_overlay("[flooring.icon_base]-corner-[NORTHWEST]", "[flooring.icon_base]_corners", NORTHWEST)
+							add_overlay(get_flooring_overlay("[flooring.icon_base]-corner-[NORTHWEST]", "[flooring.icon_base]_corners", NORTHWEST))
 				if(!(has_border & SOUTH))
 					if(!(has_border & EAST))
 						var/turf/simulated/floor/T = get_step(src, SOUTHEAST)
 						if(!(istype(T) && T.flooring && T.flooring.name == flooring.name))
-							overlays |= get_flooring_overlay("[flooring.icon_base]-corner-[SOUTHEAST]", "[flooring.icon_base]_corners", SOUTHEAST)
+							add_overlay(get_flooring_overlay("[flooring.icon_base]-corner-[SOUTHEAST]", "[flooring.icon_base]_corners", SOUTHEAST))
 					if(!(has_border & WEST))
 						var/turf/simulated/floor/T = get_step(src, SOUTHWEST)
 						if(!(istype(T) && T.flooring && T.flooring.name == flooring.name))
-							overlays |= get_flooring_overlay("[flooring.icon_base]-corner-[SOUTHWEST]", "[flooring.icon_base]_corners", SOUTHWEST)
+							add_overlay(get_flooring_overlay("[flooring.icon_base]-corner-[SOUTHWEST]", "[flooring.icon_base]_corners", SOUTHWEST))
 
-	// Hack workaround to byond crash bug
+	// Re-apply floor decals
-	//if(decals && decals.len)
+	if(LAZYLEN(decals))
-		//overlays |= decals
+		add_overlay(decals)
-	apply_decals()
 
 	if(is_plating() && !(isnull(broken) && isnull(burnt))) //temp, todo
 		icon = 'icons/turf/flooring/plating.dmi'
 		icon_state = "dmg[rand(1,4)]"
 	else if(flooring)
 		if(!isnull(broken) && (flooring.flags & TURF_CAN_BREAK))
-			overlays |= get_flooring_overlay("[flooring.icon_base]-broken-[broken]","broken[broken]") // VOREStation Edit - Eris overlays
+			add_overlay(get_flooring_overlay("[flooring.icon_base]-broken-[broken]","broken[broken]")) // VOREStation Edit - Eris overlays
 		if(!isnull(burnt) && (flooring.flags & TURF_CAN_BURN))
-			overlays |= get_flooring_overlay("[flooring.icon_base]-burned-[burnt]","burned[burnt]") // VOREStation Edit - Eris overlays
+			add_overlay(get_flooring_overlay("[flooring.icon_base]-burned-[burnt]","burned[burnt]")) // VOREStation Edit - Eris overlays
 
 	if(weather_overlay)
-		overlays += weather_overlay
+		add_overlay(weather_overlay)
 
 	if(update_neighbors)
 		for(var/turf/simulated/floor/F in range(src, 1))
@@ -97,7 +96,7 @@ var/image/no_ceiling_image = null
 	// Show 'ceilingless' overlay.
 	var/turf/above = GetAbove(src)
 	if(above && isopenspace(above) && !istype(src, /turf/simulated/floor/outdoors)) // This won't apply to outdoor turfs since its assumed they don't have a ceiling anyways.
-		overlays |= no_ceiling_image
+		add_overlay(no_ceiling_image)
 
 /turf/simulated/floor/proc/get_flooring_overlay(var/cache_key, var/icon_base, var/icon_dir = 0)
 	if(!flooring_cache[cache_key])

code/game/turfs/simulated/floor_types.dm

@@ -15,17 +15,19 @@
 	var/list/decals
 
 	New(var/location = null, var/turf/simulated/shuttle/turf)
+		..(null)
 		my_turf = turf
 
 /obj/landed_holder/proc/land_on(var/turf/T)
 	//Gather destination information
-	var/old_dest_type = T.type
+	var/obj/landed_holder/new_holder = new(null)
-	var/old_dest_dir = T.dir
+	new_holder.turf_type = T.type
-	var/old_dest_icon_state = T.icon_state
+	new_holder.dir = T.dir
-	var/old_dest_icon = T.icon
+	new_holder.icon = T.icon
-	var/list/old_dest_overlays = T.overlays.Copy()
+	new_holder.icon_state =  T.icon_state
-	var/list/old_dest_underlays = T.underlays.Copy()
+	new_holder.copy_overlays(T, TRUE)
-	var/list/old_dest_decals = T.decals ? T.decals.Copy() : null
+	new_holder.underlays = T.underlays.Copy()
+	new_holder.decals = T.decals ? T.decals.Copy() : null
 
 	//Set the destination to be like us
 	T.Destroy()
@@ -33,7 +35,7 @@
 	new_dest.set_dir(my_turf.dir)
 	new_dest.icon_state = my_turf.icon_state
 	new_dest.icon = my_turf.icon
-	new_dest.overlays = my_turf.overlays
+	new_dest.copy_overlays(my_turf, TRUE)
 	new_dest.underlays = my_turf.underlays
 	new_dest.decals = my_turf.decals
 	//Shuttle specific stuff
@@ -43,18 +45,9 @@
 	new_dest.join_flags = my_turf.join_flags
 	new_dest.join_group = my_turf.join_group
 
-	if(new_dest.decals)
+	// Associate the holder with the new turf.
-		new_dest.apply_decals()
+	new_holder.my_turf = new_dest
-
+	new_dest.landed_holder = new_holder
-	//Tell the new turf about what was there before
-	new_dest.landed_holder = new(turf = new_dest)
-	new_dest.landed_holder.turf_type = old_dest_type
-	new_dest.landed_holder.dir = old_dest_dir
-	new_dest.landed_holder.icon = old_dest_icon
-	new_dest.landed_holder.icon_state = old_dest_icon_state
-	new_dest.landed_holder.overlays = old_dest_overlays
-	new_dest.landed_holder.underlays = old_dest_underlays
-	new_dest.landed_holder.decals = old_dest_decals
 
 	//Update underlays if necessary (interior corners won't have changed).
 	if(new_dest.takes_underlays && !new_dest.interior_corner)
@@ -70,11 +63,9 @@
 		new_source.set_dir(dir)
 		new_source.icon_state = icon_state
 		new_source.icon = icon
-		new_source.overlays = overlays
+		new_source.copy_overlays(src, TRUE)
 		new_source.underlays = underlays
 		new_source.decals = decals
-		if(new_source.decals)
-			new_source.apply_decals()
 	else
 		new_source = my_turf.ChangeTurf(get_base_turf_by_area(my_turf),,1)
 

code/game/turfs/simulated/outdoors/outdoors.dm

@@ -44,7 +44,9 @@ var/list/outdoor_turfs = list()
 		planet_controller.unallocateTurf(src)
 	else // This is happening during map gen, if there's no planet_controller (hopefully).
 		outdoor_turfs -= src
-	qdel(weather_overlay)
+	if(weather_overlay)
+		cut_overlay(weather_overlay)
+		qdel_null(weather_overlay)
 	update_icon()
 
 /turf/simulated/post_change()
@@ -67,15 +69,14 @@ var/list/outdoor_turfs = list()
 					var/image/I = image(icon = 'icons/turf/outdoors_edge.dmi', icon_state = "[T.get_edge_icon_state()]-edge", dir = checkdir)
 					I.plane = 0
 					turf_edge_cache[cache_key] = I
-				overlays += turf_edge_cache[cache_key]
+				add_overlay(turf_edge_cache[cache_key])
 
 /turf/simulated/proc/get_edge_icon_state()
 	return icon_state
 
 /turf/simulated/floor/outdoors/update_icon()
-	overlays.Cut()
-	update_icon_edge()
 	..()
+	update_icon_edge()
 
 /turf/simulated/floor/outdoors/mud
 	name = "mud"

code/game/turfs/simulated/outdoors/snow.dm

@@ -17,10 +17,9 @@
 	. = ..()
 
 /turf/simulated/floor/outdoors/snow/update_icon()
-	overlays.Cut()
 	..()
 	for(var/d in crossed_dirs)
-		overlays += image(icon = 'icons/turf/outdoors.dmi', icon_state = "snow_footprints", dir = text2num(d))
+		add_overlay(image(icon = 'icons/turf/outdoors.dmi', icon_state = "snow_footprints", dir = text2num(d)))
 
 /turf/simulated/floor/outdoors/snow/attackby(var/obj/item/W, var/mob/user)
 	if(istype(W, /obj/item/weapon/shovel))

code/game/turfs/simulated/wall_icon.dm

@@ -47,36 +47,36 @@
 	if(!damage_overlays[1]) //list hasn't been populated
 		generate_overlays()
 
-	overlays.Cut()
+	cut_overlays()
 	var/image/I
 
 	if(!density)
 		I = image('icons/turf/wall_masks.dmi', "[material.icon_base]fwall_open")
 		I.color = material.icon_colour
-		overlays += I
+		add_overlay(I)
 		return
 
 	for(var/i = 1 to 4)
 		I = image('icons/turf/wall_masks.dmi', "[material.icon_base][wall_connections[i]]", dir = 1<<(i-1))
 		I.color = material.icon_colour
-		overlays += I
+		add_overlay(I)
 
 	if(reinf_material)
 		if(construction_stage != null && construction_stage < 6)
 			I = image('icons/turf/wall_masks.dmi', "reinf_construct-[construction_stage]")
 			I.color = reinf_material.icon_colour
-			overlays += I
+			add_overlay(I)
 		else
 			if("[reinf_material.icon_reinf]0" in icon_states('icons/turf/wall_masks.dmi'))
 				// Directional icon
 				for(var/i = 1 to 4)
 					I = image('icons/turf/wall_masks.dmi', "[reinf_material.icon_reinf][wall_connections[i]]", dir = 1<<(i-1))
 					I.color = reinf_material.icon_colour
-					overlays += I
+					add_overlay(I)
 			else
 				I = image('icons/turf/wall_masks.dmi', reinf_material.icon_reinf)
 				I.color = reinf_material.icon_colour
-				overlays += I
+				add_overlay(I)
 
 	if(damage != 0)
 		var/integrity = material.integrity
@@ -87,7 +87,7 @@
 		if(overlay > damage_overlays.len)
 			overlay = damage_overlays.len
 
-		overlays += damage_overlays[overlay]
+		add_overlay(damage_overlays[overlay])
 	return
 
 /turf/simulated/wall/proc/generate_overlays()

code/game/turfs/simulated/wall_types.dm

@@ -224,15 +224,7 @@
 
 /turf/simulated/shuttle/wall/voidcraft/update_icon()
 	if(stripe_color)
-		overlays = list() //VOREStation Edit - Another place with overlay nonsense.
+		cut_overlays()
 		var/image/I = image(icon = src.icon, icon_state = "o_[icon_state]")
 		I.color = stripe_color
-		//VOREStation Add - Shenanigans around this because of the bullshit byond bug
+		add_overlay(I)
-		var/pre_overlays = overlays.len
-		overlays.Add(I)
-		var/post_overlays = overlays.len
-		if(post_overlays != (pre_overlays + 1))
-			world.log << "Corrupted overlays on [x],[y],[z] voidcraft wall"
-			new type(src)
-			return
-		//VOREStation Add End

code/game/turfs/simulated/wall_types_vr.dm

@@ -26,7 +26,7 @@
 var/list/flesh_overlay_cache = list()
 
 /turf/simulated/flesh/update_icon(var/update_neighbors)
-	overlays.Cut()
+	cut_overlays()
 
 	if(density)
 		icon = 'icons/turf/stomach_vr.dmi'
@@ -37,7 +37,7 @@ var/list/flesh_overlay_cache = list()
 				var/place_dir = turn(direction, 180)
 				if(!flesh_overlay_cache["flesh_side_[place_dir]"])
 					flesh_overlay_cache["flesh_side_[place_dir]"] = image('icons/turf/stomach_vr.dmi', "flesh_side", dir = place_dir)
-				T.overlays += flesh_overlay_cache["flesh_side_[place_dir]"]
+				add_overlay(flesh_overlay_cache["flesh_side_[place_dir]"])
 
 	if(update_neighbors)
 		for(var/direction in alldirs)

code/game/turfs/simulated/water.dm

@@ -16,7 +16,6 @@
 	update_icon()
 
 /turf/simulated/floor/water/update_icon()
-	overlays.Cut()
 	..() // To get the edges.
 	icon_state = water_state
 	var/image/floorbed_sprite = image(icon = 'icons/turf/outdoors.dmi', icon_state = under_state)
@@ -129,16 +128,16 @@ var/list/shoreline_icon_cache = list()
 // Water sprites are really annoying, so let BYOND sort it out.
 /turf/simulated/floor/water/shoreline/update_icon()
 	underlays.Cut()
-	overlays.Cut()
+	cut_overlays()
 	..() // Get the underlay first.
 	var/cache_string = "[initial(icon_state)]_[water_state]_[dir]"
 	if(cache_string in shoreline_icon_cache) // Check to see if an icon already exists.
-		overlays += shoreline_icon_cache[cache_string]
+		add_overlay(shoreline_icon_cache[cache_string])
 	else // If not, make one, but only once.
 		var/icon/shoreline_water = icon(src.icon, "shoreline_water", src.dir)
 		var/icon/shoreline_subtract = icon(src.icon, "[initial(icon_state)]_subtract", src.dir)
 		shoreline_water.Blend(shoreline_subtract,ICON_SUBTRACT)
 
 		shoreline_icon_cache[cache_string] = shoreline_water
-		overlays += shoreline_icon_cache[cache_string]
+		add_overlay(shoreline_icon_cache[cache_string])
 

code/game/turfs/snow/snow.dm

@@ -26,12 +26,12 @@
     . = ..()
 
 /turf/snow/update_icon()
-    overlays.Cut()
+    cut_overlays()
     for(var/d in crossed_dirs)
         var/amt = crossed_dirs[d]
 
         for(var/i in 1 to amt)
-            overlays += icon(icon, "footprint[i]", text2num(d))
+            add_overlay(image(icon, "footprint[i]", text2num(d)))
 
 /turf/snow/snow2
 	name = "snow"

code/game/turfs/space/cracked_asteroid.dm

@@ -10,7 +10,8 @@
 /turf/space/cracked_asteroid/is_space() // So people don't start floating when standing on it.
 	return FALSE
 
-/turf/space/cracked_asteroid/New()
+// u wot m8? ~Leshana
-	..()
+// /turf/space/cracked_asteroid/New()
-	spawn(2 SECONDS)
+// 	..()
-		overlays.Cut()
+// 	spawn(2 SECONDS)
+// 		overlays.Cut()

code/game/turfs/unsimulated/beach.dm

@@ -17,7 +17,7 @@
 
 /turf/unsimulated/beach/water/New()
 	..()
-	overlays += image("icon"='icons/misc/beach.dmi',"icon_state"="water2","layer"=MOB_LAYER+0.1)
+	add_overlay(image("icon"='icons/misc/beach.dmi',"icon_state"="water2","layer"=MOB_LAYER+0.1))
 
 /turf/simulated/floor/beach
 	name = "Beach"
@@ -56,4 +56,4 @@
 
 /turf/simulated/floor/beach/water/New()
 	..()
-	overlays += image("icon"='icons/misc/beach.dmi',"icon_state"="water5","layer"=MOB_LAYER+0.1)
+	add_overlay(image("icon"='icons/misc/beach.dmi',"icon_state"="water5","layer"=MOB_LAYER+0.1))

code/modules/holodeck/HolodeckObjects.dm

@@ -107,7 +107,7 @@
 /turf/simulated/floor/holofloor/desert/New()
 	..()
 	if(prob(10))
-		overlays += "asteroid[rand(0,9)]"
+		add_overlay("asteroid[rand(0,9)]")
 
 /obj/structure/holostool
 	name = "stool"

code/modules/multiz/turf.dm

@@ -73,7 +73,7 @@
 * Update icon and overlays of open space to be that of the turf below, plus any visible objects on that turf.
 */
 /turf/simulated/open/update_icon()
-	overlays = list() // Edit - Overlays are being crashy when modified.
+	cut_overlays() // Edit - Overlays are being crashy when modified.
 	update_icon_edge()// Add - Get grass into open spaces and whatnot.
 	var/turf/below = GetBelow(src)
 	if(below)
@@ -86,12 +86,7 @@
 			bottom_turf.plane = src.plane
 			bottom_turf.color = below.color
 			underlays = list(bottom_turf)
-		// Hack workaround to byond crash bug - Include the magic overlay holder object.
+		copy_overlays(below)
-		overlays += below.overlays
-		// if(below.overlay_holder)
-		// 	overlays += (below.overlays + below.overlay_holder.overlays)
-		// else
-		// 	overlays += below.overlays
 
 		// get objects (not mobs, they are handled by /obj/zshadow)
 		var/list/o_img = list()
@@ -104,16 +99,10 @@
 			temp2.overlays += O.overlays
 			// TODO Is pixelx/y needed?
 			o_img += temp2
-		var/overlays_pre = overlays.len
+		add_overlay(o_img)
-		overlays += o_img
-		var/overlays_post = overlays.len
-		if(overlays_post != (overlays_pre + o_img.len)) //Here we go!
-			world.log << "Corrupted openspace turf at [x],[y],[z] being replaced. Pre: [overlays_pre], Post: [overlays_post]"
-			new /turf/simulated/open(src)
-			return //Let's get out of here.
 
 		if(!below_is_open)
-			overlays += over_OS_darkness
+			add_overlay(over_OS_darkness)
 
 		return 0
 	return PROCESS_KILL

maps/tether/submaps/beach/_beach.dm

@@ -147,7 +147,7 @@
 
 /turf/simulated/floor/beach/coastwater/New()
 	..()
-	overlays += image("icon"='icons/misc/beach.dmi',"icon_state"="water","layer"=MOB_LAYER+0.1)
+	add_overlay(image("icon"='icons/misc/beach.dmi',"icon_state"="water","layer"=MOB_LAYER+0.1))
 
 // -- Areas -- //
 

vorestation.dme

@@ -196,7 +196,6 @@
 #include "code\controllers\subsystems\air.dm"
 #include "code\controllers\subsystems\airflow.dm"
 #include "code\controllers\subsystems\atoms.dm"
-#include "code\controllers\subsystems\floor_decals.dm"
 #include "code\controllers\subsystems\garbage.dm"
 #include "code\controllers\subsystems\lighting.dm"
 #include "code\controllers\subsystems\machines.dm"
@@ -1211,7 +1210,6 @@
 #include "code\game\turfs\flooring\flooring_premade.dm"
 #include "code\game\turfs\flooring\flooring_vr.dm"
 #include "code\game\turfs\flooring\shuttle_vr.dm"
-#include "code\game\turfs\flooring\turf_overlay_holder.dm"
 #include "code\game\turfs\initialization\init.dm"
 #include "code\game\turfs\initialization\maintenance.dm"
 #include "code\game\turfs\simulated\floor.dm"