Fix a ton of harddels (#17803)

* Fix a ton of harddels

* Out of scope

* Stupid

code/datums/datum.dm

@@ -100,21 +100,26 @@
 	if(dc)
 		var/all_components = dc[/datum/component]
 		if(length(all_components))
-			for(var/I in all_components)
-				var/datum/component/C = I
-				qdel(C, FALSE, TRUE)
+			for(var/datum/component/component as anything in all_components)
+				qdel(component, FALSE, TRUE)
 		else
 			var/datum/component/C = all_components
 			qdel(C, FALSE, TRUE)
 		dc.Cut()
 
+	clear_signal_refs()
+
+	return QDEL_HINT_QUEUE
+
+///Only override this if you know what you're doing. You do not know what you're doing
+///This is a threat
+/datum/proc/clear_signal_refs()
 	var/list/lookup = comp_lookup
 	if(lookup)
 		for(var/sig in lookup)
 			var/list/comps = lookup[sig]
 			if(length(comps))
-				for(var/i in comps)
-					var/datum/component/comp = i
+				for(var/datum/component/comp as anything in comps)
 					comp.UnregisterSignal(src, sig)
 			else
 				var/datum/component/comp = comps
@@ -124,8 +129,6 @@
 	for(var/target in signal_procs)
 		UnregisterSignal(target, signal_procs[target])
 
-	return QDEL_HINT_QUEUE
-
 #ifdef DATUMVAR_DEBUGGING_MODE
 /datum/proc/save_vars()
 	cached_vars = list()

code/datums/hud.dm

@@ -65,14 +65,17 @@ GLOBAL_LIST_INIT(huds, list(
 	GLOB.all_huds -= src
 	return ..()
 
-/datum/atom_hud/proc/remove_hud_from(mob/M)	// this is called when something disables HUD
+/datum/atom_hud/proc/remove_hud_from(mob/M, absolute = FALSE)
 	if(!M || !hudusers[M])
 		return
-	if (!--hudusers[M])
+	if (absolute || !--hudusers[M])
+		UnregisterSignal(M, COMSIG_PARENT_QDELETING)
 		var/M_is_silicon = FALSE
 		if(do_silicon_check && istype(M, /mob/living/silicon))
 			M_is_silicon = TRUE
 		hudusers -= M
+		if(next_time_allowed[M])
+			next_time_allowed -= M
 		if(queued_to_see[M])
 			queued_to_see -= M
 		else
@@ -111,6 +114,7 @@ GLOBAL_LIST_INIT(huds, list(
 		return
 	if(!hudusers[M])
 		hudusers[M] = 1
+		RegisterSignal(M, COMSIG_PARENT_QDELETING, .proc/unregister_mob)
 		var/M_is_silicon = FALSE
 		if(do_silicon_check && istype(M, /mob/living/silicon))
 			M_is_silicon = TRUE
@@ -130,6 +134,10 @@ GLOBAL_LIST_INIT(huds, list(
 	else
 		hudusers[M]++		// the hell does this do?
 
+/datum/atom_hud/proc/unregister_mob(datum/source, force)
+	SIGNAL_HANDLER
+	remove_hud_from(source, TRUE)
+
 /datum/atom_hud/proc/show_hud_images_after_cooldown(M, M_is_silicon)
 	if(queued_to_see[M])
 		queued_to_see -= M

code/datums/mind.dm

@@ -89,15 +89,16 @@
 	/// The timer for the afk verb
 	var/afk_verb_timer
 
-/datum/mind/New(key)
-	src.key = key
+/datum/mind/New(_key)
+	key = _key
 	soulOwner = src
 	martial_art = default_martial_art
 
 /datum/mind/Destroy()
 	SSticker.minds -= src
-	if(islist(antag_datums))
-		QDEL_LIST(antag_datums)
+	QDEL_NULL(antag_hud)
+	QDEL_LIST(antag_datums)
+	QDEL_NULL(language_holder)
 	current = null
 	soulOwner = null
 	return ..()

code/game/area/areas.dm

@@ -263,6 +263,7 @@ GLOBAL_LIST_EMPTY(teleportlocs)
 /area/Destroy()
 	if(GLOB.areas_by_type[type] == src)
 		GLOB.areas_by_type[type] = null
+	GLOB.sortedAreas -= src
 	GLOB.areas -= src
 	STOP_PROCESSING(SSobj, src)
 	return ..()

code/game/atoms.dm

@@ -206,16 +206,18 @@
   */
 /atom/Destroy()
 	if(alternate_appearances)
-		for(var/K in alternate_appearances)
-			var/datum/atom_hud/alternate_appearance/AA = alternate_appearances[K]
-			AA.remove_from_hud(src)
+		for(var/current_alternate_appearance in alternate_appearances)
+			var/datum/atom_hud/alternate_appearance/selected_alternate_appearance = alternate_appearances[current_alternate_appearance]
+			selected_alternate_appearance.remove_from_hud(src)
 
 	if(reagents)
 		qdel(reagents)
 
 	orbiters = null // The component is attached to us normaly and will be deleted elsewhere
 
-	LAZYCLEARLIST(overlays)
+	// Checking length(overlays) before cutting has significant speed benefits
+	if (length(overlays))
+		overlays.Cut()
 	LAZYCLEARLIST(priority_overlays)
 
 	for(var/i in targeted_by)
@@ -225,6 +227,8 @@
 	targeted_by = null
 
 	QDEL_NULL(light)
+	if (length(light_sources))
+		light_sources.Cut()
 
 	return ..()
 

code/game/atoms_movable.dm

@@ -72,9 +72,45 @@
 	if(light_system == MOVABLE_LIGHT)
 		AddComponent(/datum/component/overlay_lighting)
 
-/atom/movable/Destroy()
+/atom/movable/Destroy(force)
+	QDEL_NULL(proximity_monitor)
+	QDEL_NULL(language_holder)
 	QDEL_NULL(em_block)
-	return ..()
+
+	unbuckle_all_mobs(force = TRUE)
+
+	if(loc)
+		//Restore air flow if we were blocking it (movables with ATMOS_PASS_PROC will need to do this manually if necessary)
+		if(((CanAtmosPass == ATMOS_PASS_DENSITY && density) || CanAtmosPass == ATMOS_PASS_NO) && isturf(loc))
+			CanAtmosPass = ATMOS_PASS_YES
+			air_update_turf(TRUE)
+		loc.handle_atom_del(src)
+
+	invisibility = INVISIBILITY_ABSTRACT
+
+	if(pulledby)
+		pulledby.stop_pulling()
+	if(pulling)
+		stop_pulling()
+
+	if(orbiting)
+		orbiting.end_orbit(src)
+		orbiting = null
+	
+	LAZYCLEARLIST(client_mobs_in_contents)
+
+	. = ..()
+
+	for(var/movable_content in contents)
+		qdel(movable_content)
+	
+	moveToNullspace()
+
+	vis_locs = null //clears this atom out of all viscontents
+
+	// Checking length(vis_contents) before cutting has significant speed benefits
+	if (length(vis_contents))
+		vis_contents.Cut()
 
 /atom/movable/proc/update_emissive_block()
 	if(blocks_emissive != EMISSIVE_BLOCK_GENERIC)
@@ -438,30 +474,6 @@
 	SSdemo.mark_dirty(src)
 	return TRUE
 
-/atom/movable/Destroy(force)
-	QDEL_NULL(proximity_monitor)
-	QDEL_NULL(language_holder)
-
-	unbuckle_all_mobs(force=1)
-
-	. = ..()
-	if(loc)
-		//Restore air flow if we were blocking it (movables with ATMOS_PASS_PROC will need to do this manually if necessary)
-		if(((CanAtmosPass == ATMOS_PASS_DENSITY && density) || CanAtmosPass == ATMOS_PASS_NO) && isturf(loc))
-			CanAtmosPass = ATMOS_PASS_YES
-			air_update_turf(TRUE)
-		loc.handle_atom_del(src)
-	for(var/atom/movable/AM in contents)
-		qdel(AM)
-	moveToNullspace()
-	invisibility = INVISIBILITY_ABSTRACT
-	if(pulledby)
-		pulledby.stop_pulling()
-
-	if(orbiting)
-		orbiting.end_orbit(src)
-		orbiting = null
-
 // Make sure you know what you're doing if you call this, this is intended to only be called by byond directly.
 // You probably want CanPass()
 /atom/movable/Cross(atom/movable/AM)

code/game/objects/effects/anomalies.dm

@@ -52,7 +52,7 @@
 /obj/effect/anomaly/Destroy()
 	GLOB.poi_list.Remove(src)
 	STOP_PROCESSING(SSobj, src)
-	qdel(countdown)
+	QDEL_NULL(countdown)
 	return ..()
 
 /obj/effect/anomaly/proc/anomalyEffect(delta_time)

code/game/objects/items/chrono_eraser.dm

@@ -133,6 +133,10 @@
 	if(istype(C))
 		gun = C.gun
 
+/obj/item/projectile/energy/chrono_beam/Destroy()
+	gun = null
+	return ..()
+
 /obj/item/projectile/energy/chrono_beam/on_hit(atom/target)
 	if(target && gun && isliving(target))
 		var/obj/structure/chrono_field/F = new(target.loc, target, gun)
@@ -151,7 +155,9 @@
 		gun = loc
 	. = ..()
 
-
+/obj/item/ammo_casing/energy/chrono_beam/Destroy()
+	gun = null
+	return ..()
 
 
 

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

@@ -14,6 +14,10 @@
 	var/valve_open = FALSE
 	var/toggle = TRUE
 
+/obj/item/transfer_valve/Destroy()
+	attached_device = null
+	return ..()
+
 /obj/item/transfer_valve/IsAssemblyHolder()
 	return TRUE
 
@@ -246,4 +250,4 @@
 				attached_device = null
 				. = TRUE
 
-	update_icon()
+	update_icon()

code/game/objects/items/melee/energy.dm

@@ -229,6 +229,10 @@
 	spark_system.set_up(5, 0, src)
 	spark_system.attach(src)
 
+/obj/item/melee/transforming/energy/blade/Destroy()
+	QDEL_NULL(spark_system)
+	return ..()
+
 /obj/item/melee/transforming/energy/blade/transform_weapon(mob/living/user, supress_message_text)
 	return
 

code/game/objects/items/melee/misc.dm

@@ -498,7 +498,7 @@
 	if(!iscarbon(user))
 		target.LAssailant = null
 	else
-		target.LAssailant = user
+		target.LAssailant = WEAKREF(user)
 	cooldown_check = world.time + cooldown
 
 /obj/item/melee/classic_baton/telescopic/contractor_baton/get_wait_description()

code/game/objects/structures/beds_chairs/bed.dm

@@ -173,7 +173,7 @@
 	anchored = FALSE
 	buildstacktype = /obj/item/stack/sheet/mineral/wood
 	buildstackamount = 10
-	var/mob/living/owner = null
+	var/owned = FALSE
 
 /obj/structure/bed/dogbed/ian
 	desc = "Ian's bed! Looks comfy."
@@ -200,10 +200,14 @@
 	name = "Birdboat's bed"
 	anchored = TRUE
 
+///Used to set the owner of a dogbed, returns FALSE if called on an owned bed or an invalid one, TRUE if the possesion succeeds
 /obj/structure/bed/dogbed/proc/update_owner(mob/living/M)
-	owner = M
+	if(owned || type != /obj/structure/bed/dogbed) //Only marked beds work, this is hacky but I'm a hacky man
+		return FALSE //Failed
+	owned = TRUE
 	name = "[M]'s bed"
 	desc = "[M]'s bed! Looks comfy."
+	return TRUE //Let any callers know that this bed is ours now
 
 /obj/structure/bed/dogbed/buckle_mob(mob/living/M, force, check_loc)
 	. = ..()

code/game/turfs/turf.dm

@@ -121,6 +121,13 @@ GLOBAL_LIST_EMPTY(station_turfs)
 	requires_activation = FALSE
 	..()
 
+/// WARNING WARNING
+/// Turfs DO NOT lose their signals when they get replaced, REMEMBER THIS
+/// It's possible because turfs are fucked, and if you have one in a list and it's replaced with another one, the list ref points to the new turf
+/// We do it because moving signals over was needlessly expensive, and bloated a very commonly used bit of code
+/turf/clear_signal_refs()
+	return
+
 /turf/attack_hand(mob/user)
 	. = ..()
 	if(SEND_SIGNAL(user, COMSIG_MOB_ATTACK_HAND_TURF, src) & COMPONENT_NO_ATTACK_HAND)

code/modules/antagonists/abductor/equipment/gland.dm

@@ -148,8 +148,8 @@
 	owner.vomit(20)
 
 	var/mob/living/simple_animal/slime/Slime = new(get_turf(owner), "grey")
-	Slime.Friends = list(owner)
-	Slime.Leader = owner
+	Slime.set_friends(list(owner))
+	Slime.set_leader(owner)
 
 /obj/item/organ/heart/gland/mindshock
 	true_name = "neural crosstalk uninhibitor"

code/modules/antagonists/blob/blobstrains/_blobstrain.dm

@@ -22,6 +22,10 @@ GLOBAL_LIST_INIT(valid_blobstrains, subtypesof(/datum/blobstrain) - list(/datum/
 		stack_trace("blobstrain created without overmind")
 	overmind = new_overmind
 
+/datum/blobstrain/Destroy()
+	overmind = null
+	return ..()
+
 /datum/blobstrain/proc/on_gain()
 	overmind.color = complementary_color
 	point_rate = point_rate * overmind.basemodifier

code/modules/antagonists/blob/overmind.dm

@@ -175,6 +175,7 @@ GLOBAL_LIST_EMPTY(blob_nodes)
 	SSticker.force_ending = 1
 
 /mob/camera/blob/Destroy()
+	QDEL_NULL(blobstrain)
 	for(var/BL in GLOB.blobs)
 		var/obj/structure/blob/B = BL
 		if(B && B.overmind == src)

code/modules/antagonists/disease/disease_disease.dm

@@ -12,6 +12,7 @@
 
 /datum/disease/advance/sentient_disease/Destroy()
 	. = ..()
+	overmind = null
 	GLOB.sentient_disease_instances -= src
 
 /datum/disease/advance/sentient_disease/remove_disease()

code/modules/antagonists/disease/disease_mob.dm

@@ -73,10 +73,12 @@ the new instance inside the host to be updated to the template's stats.
 /mob/camera/disease/Destroy()
 	. = ..()
 	QDEL_NULL(adaptation_menu_action)
+	disease_template = null
 	for(var/V in GLOB.sentient_disease_instances)
 		var/datum/disease/advance/sentient_disease/S = V
 		if(S.overmind == src)
 			S.overmind = null
+	browser = null
 
 /mob/camera/disease/Login()
 	..()

code/modules/assembly/assembly.dm

@@ -28,6 +28,10 @@
 
 	var/next_activate = 0 //When we're next allowed to activate - for spam control
 
+/obj/item/assembly/Destroy()
+	holder = null
+	return ..()
+
 /obj/item/assembly/get_part_rating()
 	return 1
 
@@ -132,4 +136,4 @@
 	return src
 
 /obj/item/assembly/ui_state(mob/user)
-	return GLOB.hands_state
+	return GLOB.hands_state

code/modules/atmospherics/machinery/portable/portable_atmospherics.dm

@@ -24,11 +24,9 @@
 	return 1
 
 /obj/machinery/portable_atmospherics/Destroy()
-	SSair.atmos_machinery -= src
-
 	disconnect()
-	qdel(air_contents)
-	air_contents = null
+	QDEL_NULL(air_contents)
+	SSair.atmos_machinery -= src
 
 	return ..()
 

code/modules/awaymissions/mission_code/Cabin.dm

@@ -25,7 +25,7 @@
 	var/active = 1
 
 /obj/structure/firepit/Initialize()
-	..()
+	. = ..()
 	toggleFirepit()
 
 /obj/structure/firepit/interact(mob/living/user)

code/modules/clothing/spacesuits/chronosuit.dm

@@ -65,6 +65,7 @@
 
 /obj/item/clothing/suit/space/chronos/Destroy()
 	dropped()
+	QDEL_NULL(teleport_now)
 	return ..()
 
 /obj/item/clothing/suit/space/chronos/emp_act(severity)
@@ -330,6 +331,10 @@
 	check_flags = AB_CHECK_CONSCIOUS //|AB_CHECK_INSIDE
 	var/obj/item/clothing/suit/space/chronos/chronosuit = null
 
+/datum/action/innate/chrono_teleport/Destroy()
+	chronosuit = null
+	return ..()
+
 /datum/action/innate/chrono_teleport/IsAvailable()
 	return (chronosuit && chronosuit.activated && chronosuit.camera && !chronosuit.teleporting)
 

code/modules/clothing/spacesuits/hardsuit.dm

@@ -1030,11 +1030,7 @@
 	allowed = list(/obj/item/gun, /obj/item/ammo_box, /obj/item/ammo_casing, /obj/item/melee/baton, /obj/item/melee/transforming/energy/sword/saber, /obj/item/restraints/handcuffs, /obj/item/tank/internals)
 	helmettype = /obj/item/clothing/head/helmet/space/hardsuit/shielded/syndi
 	slowdown = 0
-
-
-/obj/item/clothing/suit/space/hardsuit/shielded/syndi/Initialize()
-	jetpack = new /obj/item/tank/jetpack/suit(src)
-	. = ..()
+	jetpack = /obj/item/tank/jetpack/suit
 
 /obj/item/clothing/head/helmet/space/hardsuit/shielded/syndi
 	name = "blood-red hardsuit helmet"

code/modules/clothing/suits/toggles.dm

@@ -130,11 +130,11 @@
 	. = ..()
 
 /obj/item/clothing/suit/space/hardsuit/Destroy()
-	if(helmet)
+	if(!QDELETED(helmet))
 		helmet.suit = null
-		qdel(helmet)
+		QDEL_NULL(helmet)
 	if(jetpack && istype(jetpack))
-		qdel(jetpack)
+		QDEL_NULL(jetpack)
 	return ..()
 
 /obj/item/clothing/head/helmet/space/hardsuit/Destroy()

code/modules/fields/timestop.dm

@@ -42,7 +42,7 @@
 		timestop()
 
 /obj/effect/timestop/Destroy()
-	qdel(chronofield)
+	QDEL_NULL(chronofield)
 	return ..()
 
 /obj/effect/timestop/proc/timestop()

code/modules/food_and_drinks/kitchen_machinery/food_cart.dm

@@ -25,6 +25,7 @@
 
 /obj/machinery/food_cart/Destroy()
 	QDEL_NULL(mixer)
+	stored_food.Cut()
 	return ..()
 
 /obj/machinery/food_cart/ui_interact(mob/user)

code/modules/mining/laborcamp/laborstacker.dm

@@ -31,6 +31,13 @@ GLOBAL_LIST(labor_sheet_values)
 			sheet_list += list(list("ore" = initial(sheet.name), "value" = initial(sheet.point_value)))
 		GLOB.labor_sheet_values = sortList(sheet_list, /proc/cmp_sheet_list)
 
+/obj/machinery/mineral/labor_claim_console/Destroy()
+	QDEL_NULL(Radio)
+	if(stacking_machine)
+		stacking_machine.console = null
+		stacking_machine = null
+	return ..()
+
 /proc/cmp_sheet_list(list/a, list/b)
 	return a["value"] - b["value"]
 
@@ -109,9 +116,7 @@ GLOBAL_LIST(labor_sheet_values)
 /obj/machinery/mineral/labor_claim_console/proc/locate_stacking_machine()
 	stacking_machine = locate(/obj/machinery/mineral/stacking_machine, get_step(src, machinedir))
 	if(stacking_machine)
-		stacking_machine.CONSOLE = src
-	else
-		qdel(src)
+		stacking_machine.console = src
 
 /obj/machinery/mineral/labor_claim_console/emag_act(mob/user)
 	if(!(obj_flags & EMAGGED))

code/modules/mining/lavaland/necropolis_chests.dm

@@ -340,6 +340,12 @@ GLOBAL_LIST_EMPTY(aide_list)
 	var/obj/item/warp_cube/linked
 	var/teleporting = FALSE
 
+/obj/item/warp_cube/Destroy()
+	if(!QDELETED(linked))
+		qdel(linked)
+	linked = null
+	return ..()
+
 /obj/item/warp_cube/attack_self(mob/user)
 	var/turf/current_location = get_turf(user)//yogs added a current location check that was totally ripped from the hand tele code honk
 	var/area/current_area = current_location.loc //yogs more location check stuff

code/modules/mining/machine_stacking.dm

@@ -14,7 +14,7 @@
 	. = ..()
 	machine = locate(/obj/machinery/mineral/stacking_machine, get_step(src, machinedir))
 	if (machine)
-		machine.CONSOLE = src
+		machine.console = src
 
 /obj/machinery/mineral/stacking_unit_console/ui_interact(mob/user)
 	. = ..()
@@ -84,7 +84,7 @@
 	circuit = /obj/item/circuitboard/machine/stacking_machine
 	input_dir = EAST
 	output_dir = WEST
-	var/obj/machinery/mineral/stacking_unit_console/CONSOLE
+	var/obj/machinery/mineral/stacking_unit_console/console
 	var/stk_types = list()
 	var/stk_amt   = list()
 	var/stack_list[0] //Key: Type.  Value: Instance of type.
@@ -177,8 +177,8 @@
 /obj/machinery/mineral/stacking_machine/multitool_act(mob/living/user, obj/item/multitool/M)
 	if(istype(M))
 		if(istype(M.buffer, /obj/machinery/mineral/stacking_unit_console) && !panel_open)
-			CONSOLE = M.buffer
-			CONSOLE.machine = src
+			console = M.buffer
+			console.machine = src
 			to_chat(user, span_notice("You link [src] to the console in [M]'s buffer."))
 			return TRUE
 	if(panel_open)

code/modules/mob/dead/observer/observer.dm

@@ -164,6 +164,13 @@ GLOBAL_VAR_INIT(observer_default_invisibility, INVISIBILITY_OBSERVER)
 	addtimer(CALLBACK(src, /atom/proc/update_atom_colour), 10)
 
 /mob/dead/observer/Destroy()
+	if(data_huds_on)
+		remove_data_huds()
+	
+	// Update our old body's medhud since we're abandoning it
+	if(isliving(mind?.current))
+		mind.current.med_hud_set_status()
+
 	GLOB.ghost_images_default -= ghostimage_default
 	QDEL_NULL(ghostimage_default)
 

code/modules/mob/living/living.dm

@@ -25,21 +25,23 @@
 	med_hud_set_status()
 
 /mob/living/Destroy()
-	if(LAZYLEN(status_effects))
-		for(var/s in status_effects)
-			var/datum/status_effect/S = s
-			if(S.on_remove_on_mob_delete) //the status effect calls on_remove when its mob is deleted
-				qdel(S)
-			else
-				S.be_replaced()
+	for(var/datum/status_effect/effect as anything in status_effects)
+		// The status effect calls on_remove when its mob is deleted
+		if(effect.on_remove_on_mob_delete)
+			qdel(effect)
+		else
+			effect.be_replaced()
+	
 	if(ranged_ability)
 		ranged_ability.remove_ranged_ability(src)
+
 	if(buckled)
 		buckled.unbuckle_mob(src,force=1)
 
 	remove_from_all_data_huds()
 	GLOB.mob_living_list -= src
 	QDEL_LIST(diseases)
+	QDEL_LIST(surgeries)
 	return ..()
 
 /mob/living/onZImpact(turf/T, levels)
@@ -283,7 +285,7 @@
 		if(!iscarbon(src))
 			M.LAssailant = null
 		else
-			M.LAssailant = usr
+			M.LAssailant = WEAKREF(usr)
 		if(isliving(M))
 			var/mob/living/L = M
 			//Share diseases that are spread by touch

code/modules/mob/living/simple_animal/friendly/dog.dm

@@ -123,8 +123,7 @@
 	. = ..()
 	var/dog_area = get_area(src)
 	for(var/obj/structure/bed/dogbed/D in dog_area)
-		if(!D.owner)
-			D.update_owner(src)
+		if(D.update_owner(src)) //No muscling in on my turf you fucking parrot
 			break
 
 /mob/living/simple_animal/pet/dog/corgi/Initialize()

code/modules/mob/living/simple_animal/slime/life.dm

@@ -51,13 +51,13 @@
 			break
 
 		if(Target.health <= -70 || Target.stat == DEAD)
-			Target = null
+			set_target(null)
 			AIproc = 0
 			break
 
 		if(Target)
 			if(locate(/mob/living/simple_animal/slime) in Target.buckled_mobs)
-				Target = null
+				set_target(null)
 				AIproc = 0
 				break
 			if(!AIproc)
@@ -97,7 +97,7 @@
 				// Bug of the month candidate: slimes were attempting to move to target only if it was directly next to them, which caused them to target things, but not approach them
 					step_to(src, Target)
 			else
-				Target = null
+				set_target(null)
 				AIproc = 0
 				break
 
@@ -188,12 +188,10 @@
 	if(M.stat == DEAD) // our victim died
 		if(!client)
 			if(!rabid && !attacked)
-				if(M.LAssailant && M.LAssailant != M)
+				var/mob/last_to_hurt = M.LAssailant?.resolve()
+				if(last_to_hurt && last_to_hurt != M)
 					if(prob(50))
-						if(!(M.LAssailant in Friends))
-							Friends[M.LAssailant] = 1
-						else
-							++Friends[M.LAssailant]
+						add_friendship(last_to_hurt, 1)
 		else
 			to_chat(src, "<i>This subject does not have a strong enough life energy anymore...</i>")
 
@@ -309,7 +307,7 @@
 			--target_patience
 			if (target_patience <= 0 || SStun > world.time || Discipline || attacked || docile) // Tired of chasing or something draws out attention
 				target_patience = 0
-				Target = null
+				set_target(null)
 
 		if(AIproc && SStun > world.time)
 			return
@@ -324,7 +322,7 @@
 		if(hungry == 2 && !client) // if a slime is starving, it starts losing its friends
 			if(Friends.len > 0 && prob(1))
 				var/mob/nofriend = pick(Friends)
-				--Friends[nofriend]
+				add_friendship(nofriend, -1)
 
 		if(!Target)
 			if(will_hunt() && hungry || attacked || rabid) // Only add to the list if we need to
@@ -363,16 +361,16 @@
 
 				if(targets.len > 0)
 					if(attacked || rabid || hungry == 2)
-						Target = targets[1] // I am attacked and am fighting back or so hungry I don't even care
+						set_target(targets[1]) // I am attacked and am fighting back or so hungry I don't even care
 					else
 						for(var/mob/living/carbon/C in targets)
 							if(!Discipline && prob(5))
 								if(ishuman(C) || isalienadult(C))
-									Target = C
+									set_target(C)
 									break
 
 							if(islarva(C) || ismonkey(C))
-								Target = C
+								set_target(C)
 								break
 
 			if (Target)
@@ -446,13 +444,13 @@
 					if (Leader == who) // Already following him
 						to_say = pick("Yes...", "Lead...", "Follow...")
 					else if (Friends[who] > Friends[Leader]) // VIVA
-						Leader = who
+						set_leader(who)
 						to_say = "Yes... I follow [who]..."
 					else
 						to_say = "No... I follow [Leader]..."
 				else
 					if (Friends[who] >= SLIME_FRIENDSHIP_FOLLOW)
-						Leader = who
+						set_leader(who)
 						to_say = "I follow..."
 					else // Not friendly enough
 						to_say = pick("No...", "I no follow...")
@@ -460,27 +458,27 @@
 				if (buckled) // We are asked to stop feeding
 					if (Friends[who] >= SLIME_FRIENDSHIP_STOPEAT)
 						Feedstop()
-						Target = null
+						set_target(null)
 						if (Friends[who] < SLIME_FRIENDSHIP_STOPEAT_NOANGRY)
-							--Friends[who]
+							add_friendship(who, -1)
 							to_say = "Grrr..." // I'm angry but I do it
 						else
 							to_say = "Fine..."
 				else if (Target) // We are asked to stop chasing
 					if (Friends[who] >= SLIME_FRIENDSHIP_STOPCHASE)
-						Target = null
+						set_target(null)
 						if (Friends[who] < SLIME_FRIENDSHIP_STOPCHASE_NOANGRY)
-							--Friends[who]
+							add_friendship(who, -1)
 							to_say = "Grrr..." // I'm angry but I do it
 						else
 							to_say = "Fine..."
 				else if (Leader) // We are asked to stop following
 					if (Leader == who)
 						to_say = "Yes... I stay..."
-						Leader = null
+						set_target(null)
 					else
 						if (Friends[who] > Friends[Leader])
-							Leader = null
+							set_target(null)
 							to_say = "Yes... I stop..."
 						else
 							to_say = "No... keep follow..."
@@ -502,7 +500,7 @@
 						to_say = "No... won't stay..."
 			else if (findtext(phrase, "attack"))
 				if (rabid && prob(20))
-					Target = who
+					set_target(who)
 					AIprocess() //Wake up the slime's Target AI, needed otherwise this doesn't work
 					to_say = "ATTACK!?!?"
 				else if (Friends[who] >= SLIME_FRIENDSHIP_ATTACK)
@@ -510,14 +508,14 @@
 						if (findtext(phrase, lowertext(L.name)))
 							if (isslime(L))
 								to_say = "NO... [L] slime friend"
-								--Friends[who] //Don't ask a slime to attack its friend
+								add_friendship(who, -1) //Don't ask a slime to attack its friend
 							else if(!Friends[L] || Friends[L] < 1)
-								Target = L
+								set_target(L)
 								AIprocess()//Wake up the slime's Target AI, needed otherwise this doesn't work
 								to_say = "Ok... I attack [Target]"
 							else
 								to_say = "No... like [L] ..."
-								--Friends[who] //Don't ask a slime to attack its friend
+								add_friendship(who, -1) //Don't ask a slime to attack its friend
 							break
 				else
 					to_say = "No... no listen"

code/modules/mob/living/simple_animal/slime/slime.dm

@@ -1,3 +1,5 @@
+#define SLIME_CARES_ABOUT(to_check) (to_check && (to_check == Target || to_check == Leader || (to_check in Friends)))
+
 /mob/living/simple_animal/slime
 	name = "grey baby slime (123)"
 	icon = 'icons/mob/slimes.dmi'
@@ -107,6 +109,9 @@
 	for (var/A in actions)
 		var/datum/action/AC = A
 		AC.Remove(src)
+	set_target(null)
+	set_leader(null)
+	clear_friends()
 	return ..()
 
 /mob/living/simple_animal/slime/proc/set_colour(new_colour)
@@ -362,10 +367,7 @@
 				if(S.next_step(user,user.a_intent))
 					return 1
 	if(istype(W, /obj/item/stack/sheet/mineral/plasma) && !stat) //Let's you feed slimes plasma.
-		if (user in Friends)
-			++Friends[user]
-		else
-			Friends[user] = 1
+		add_friendship(user, 1)
 		to_chat(user, span_notice("You feed the slime the plasma. It chirps happily."))
 		var/obj/item/stack/sheet/mineral/plasma/S = W
 		S.use(1)
@@ -433,7 +435,7 @@
 	adjustBruteLoss(rand(15,20))
 	if(!client)
 		if(Target) // Like cats
-			Target = null
+			set_target(null)
 			++Discipline
 	return
 
@@ -478,8 +480,7 @@
 			if(Discipline == 1)
 				attacked = 0
 
-	if(Target)
-		Target = null
+	set_target(null)
 	if(buckled)
 		Feedstop(silent = TRUE) //we unbuckle the slime from the mob it latched onto.
 
@@ -509,5 +510,57 @@
 /mob/living/simple_animal/slime/can_be_implanted()
 	return TRUE
 
+/mob/living/simple_animal/slime/proc/set_target(new_target)
+	var/old_target = Target
+	Target = new_target
+	if(old_target && !SLIME_CARES_ABOUT(old_target))
+		UnregisterSignal(old_target, COMSIG_PARENT_QDELETING)
+	if(Target)
+		RegisterSignal(Target, COMSIG_PARENT_QDELETING, .proc/clear_memories_of, override = TRUE)
+
+/mob/living/simple_animal/slime/proc/set_leader(new_leader)
+	var/old_leader = Leader
+	Leader = new_leader
+	if(old_leader && !SLIME_CARES_ABOUT(old_leader))
+		UnregisterSignal(old_leader, COMSIG_PARENT_QDELETING)
+	if(Leader)
+		RegisterSignal(Leader, COMSIG_PARENT_QDELETING, .proc/clear_memories_of, override = TRUE)
+
+/mob/living/simple_animal/slime/proc/add_friendship(new_friend, amount = 1)
+	if(!Friends[new_friend])
+		Friends[new_friend] = 0
+	Friends[new_friend] += amount
+	if(new_friend)
+		RegisterSignal(new_friend, COMSIG_PARENT_QDELETING, .proc/clear_memories_of, override = TRUE)
+
+/mob/living/simple_animal/slime/proc/set_friendship(new_friend, amount = 1)
+	Friends[new_friend] = amount
+	if(new_friend)
+		RegisterSignal(new_friend, COMSIG_PARENT_QDELETING, .proc/clear_memories_of, override = TRUE)
+
+/mob/living/simple_animal/slime/proc/remove_friend(friend)
+	Friends -= friend
+	if(friend && !SLIME_CARES_ABOUT(friend))
+		UnregisterSignal(friend, COMSIG_PARENT_QDELETING)
+
+/mob/living/simple_animal/slime/proc/set_friends(new_buds)
+	clear_friends()
+	for(var/mob/friend as anything in new_buds)
+		set_friendship(friend, new_buds[friend])
+
+/mob/living/simple_animal/slime/proc/clear_friends()
+	for(var/mob/friend as anything in Friends)
+		remove_friend(friend)
+
+/mob/living/simple_animal/slime/proc/clear_memories_of(datum/source)
+	SIGNAL_HANDLER
+	if(source == Target)
+		set_target(null)
+	if(source == Leader)
+		set_leader(null)
+	remove_friend(source)
+
 /mob/living/simple_animal/slime/random/Initialize(mapload, new_colour, new_is_adult)
 	. = ..(mapload, pick(slime_colours), prob(50))
+
+#undef SLIME_CARES_ABOUT

code/modules/mob/mob.dm

@@ -26,20 +26,29 @@
 	remove_from_mob_list()
 	remove_from_dead_mob_list()
 	remove_from_alive_mob_list()
+	remove_from_mob_suicide_list()
+
 	focus = null
+
+	if(length(progressbars))
+		stack_trace("[src] destroyed with elements in its progressbars list")
+		progressbars = null
+
 	for (var/alert in alerts)
 		clear_alert(alert, TRUE)
-	if(observers && observers.len)
-		for(var/M in observers)
-			var/mob/dead/observe = M
+
+	if(observers?.len)
+		for(var/mob/dead/observe as anything in observers)
 			observe.reset_perspective(null)
+
 	qdel(hud_used)
-	for(var/cc in client_colours)
-		qdel(cc)
-	client_colours = null
-	ghostize()
-	..()
-	return QDEL_HINT_HARDDEL
+	QDEL_LIST(client_colours)
+	ghostize() //False, since we're deleting it currently
+
+	if(mind?.current == src) //Let's just be safe yeah? This will occasionally be cleared, but not always. Can't do it with ghostize without changing behavior
+		mind.current = null
+
+	return ..()
 
 /**
   * Intialize a mob

code/modules/mob/mob_defines.dm

@@ -151,8 +151,8 @@
 	/// Can this mob enter shuttles
 	var/move_on_shuttle = 1
 
-	///The last mob/living/carbon to push/drag/grab this mob (exclusively used by slimes friend recognition)
-	var/mob/living/carbon/LAssailant = null
+	///A weakref to the last mob/living/carbon to push/drag/grab this mob (exclusively used by slimes friend recognition)
+	var/datum/weakref/LAssailant = null
 
 	/**
 	  * construct spells and mime spells.

code/modules/mob/mob_lists.dm

@@ -20,6 +20,13 @@
 	if(client)
 		remove_from_current_living_players()
 
+///Adds a mob reference to the list of all suicided mobs
+/mob/proc/add_to_mob_suicide_list()
+	GLOB.suicided_mob_list += src
+
+///Removes a mob references from the list of all suicided mobs
+/mob/proc/remove_from_mob_suicide_list()
+	GLOB.suicided_mob_list -= src
 
 ///Adds the mob reference to the list of all the dead mobs. If mob is cliented, it adds it to the list of all dead player-mobs.
 /mob/proc/add_to_dead_mob_list()
@@ -116,4 +123,4 @@
 /mob/proc/remove_from_current_living_antags()
 	if(!SSticker?.mode)
 		return
-	SSticker.mode.current_players[CURRENT_LIVING_ANTAGS] -= src
+	SSticker.mode.current_players[CURRENT_LIVING_ANTAGS] -= src

code/modules/reagents/reagent_containers/borghypo.dm

@@ -45,6 +45,7 @@ Borg Hypospray
 
 /obj/item/reagent_containers/borghypo/Destroy()
 	STOP_PROCESSING(SSobj, src)
+	QDEL_LIST(reagent_list)
 	return ..()
 
 

code/modules/recycling/disposal/bin.dm

@@ -139,7 +139,7 @@
 		else
 			target.visible_message(span_danger("[user] has placed [target] in [src]."), span_userdanger("[user] has placed [target] in [src]."))
 			log_combat(user, target, "stuffed", addition="into [src]")
-			target.LAssailant = user
+			target.LAssailant = WEAKREF(user)
 		update_icon()
 
 /obj/machinery/disposal/relaymove(mob/user)

code/modules/research/xenobiology/crossbreeding/_status_effects.dm

@@ -469,7 +469,7 @@ datum/status_effect/rebreathing/tick()
 	for(var/mob/living/simple_animal/slime/S in range(1, get_turf(owner)))
 		if(!(owner in S.Friends))
 			to_chat(owner, span_notice("[linked_extract] pulses gently as it communicates with [S]"))
-			S.Friends[owner] = 1
+			S.set_friendship(owner, 1)
 	return ..()
 
 /datum/status_effect/stabilized/orange

code/modules/research/xenobiology/crossbreeding/burning.dm

@@ -34,7 +34,7 @@ Burning extracts:
 /obj/item/slimecross/burning/grey/do_effect(mob/user)
 	var/mob/living/simple_animal/slime/S = new(get_turf(user),"grey")
 	S.visible_message(span_danger("A baby slime emerges from [src], and it nuzzles [user] before burbling hungrily!"))
-	S.Friends[user] = 20 //Gas, gas, gas
+	S.set_friendship(user, 20) //Gas, gas, gas
 	S.bodytemperature = T0C + 400 //We gonna step on the gas.
 	S.set_nutrition(S.get_hunger_nutrition()) //Tonight, we fight!
 	..()
@@ -200,10 +200,10 @@ Burning extracts:
 	for(var/mob/living/simple_animal/slime/S in view(7, get_turf(user)))
 		if(user in S.Friends)
 			var/friendliness = S.Friends[user]
-			S.Friends = list()
-			S.Friends[user] = friendliness
+			S.clear_friends()
+			S.set_friendship(user, friendliness)
 		else
-			S.Friends = list()
+			S.clear_friends()
 		S.rabid = 1
 		S.visible_message(span_danger("The [S] is driven into a dangerous frenzy!"))
 	..()

code/modules/research/xenobiology/xenobio_camera.dm

@@ -238,7 +238,7 @@
 		if(X.monkeys >= 1)
 			var/mob/living/carbon/monkey/food = new /mob/living/carbon/monkey(remote_eye.loc, TRUE, owner)
 			if (!QDELETED(food))
-				food.LAssailant = C
+				food.LAssailant = WEAKREF(C)
 				X.monkeys--
 				X.monkeys = round(X.monkeys, 0.1)		//Prevents rounding errors
 				to_chat(owner, "[X] now has [X.monkeys] monkeys stored.")
@@ -440,7 +440,7 @@
 		if(X.monkeys >= 1)
 			var/mob/living/carbon/monkey/food = new /mob/living/carbon/monkey(T, TRUE, C)
 			if (!QDELETED(food))
-				food.LAssailant = C
+				food.LAssailant = WEAKREF(C)
 				X.monkeys--
 				X.monkeys = round(X.monkeys, 0.1)		//Prevents rounding errors
 				to_chat(C, "[X] now has [X.monkeys] monkeys stored.")

yogstation/code/datums/antagonists/vampire.dm

@@ -268,7 +268,7 @@
 	if(!iscarbon(owner))
 		H.LAssailant = null
 	else
-		H.LAssailant = O
+		H.LAssailant = WEAKREF(O)
 	while(do_mob(O, H, 50))
 		if(!is_vampire(O))
 			to_chat(O, span_warning("Your fangs have disappeared!"))