content

code/controllers/subsystem/persistence/_persistence.dm

@@ -335,7 +335,7 @@ SUBSYSTEM_DEF(persistence)
 		if(!istype(ending_human) || !ending_human.mind || !ending_human.client || !ending_human.client.prefs || !ending_human.client.prefs.persistent_scars)
 			continue
 
-		var/mob/living/carbon/human/original_human = ending_human.mind.original_character
+		var/mob/living/carbon/human/original_human = ending_human.mind.original_character.resolve()
 		if(!original_human || original_human.stat == DEAD || !original_human.all_scars || !(original_human == ending_human))
 			if(ending_human.client) // i was told if i don't check this every step of the way byond might decide a client ceases to exist mid proc so here we go
 				ending_human.client.prefs.scars_list["[ending_human.client.prefs.scars_index]"] = ""
@@ -356,7 +356,7 @@ SUBSYSTEM_DEF(persistence)
 		if(!istype(ending_human) || !ending_human.mind || !ending_human.client || !ending_human.client.prefs || !ending_human.client.prefs.tcg_cards)
 			continue
 
-		var/mob/living/carbon/human/original_human = ending_human.mind.original_character
+		var/mob/living/carbon/human/original_human = ending_human.mind.original_character.resolve()
 		if(!original_human || original_human.stat == DEAD || !(original_human == ending_human))
 			continue
 

code/datums/dash_weapon.dm

@@ -6,7 +6,6 @@
 	var/current_charges = 1
 	var/max_charges = 1
 	var/charge_rate = 250
-	var/mob/living/carbon/human/holder
 	var/obj/item/dashing_item
 	var/dash_sound = 'sound/magic/blink.ogg'
 	var/recharge_sound = 'sound/magic/charge.ogg'
@@ -17,7 +16,6 @@
 /datum/action/innate/dash/Grant(mob/user, obj/dasher)
 	. = ..()
 	dashing_item = dasher
-	holder = user
 
 /datum/action/innate/dash/IsAvailable(silent = FALSE)
 	if(current_charges > 0)
@@ -26,7 +24,7 @@
 		return FALSE
 
 /datum/action/innate/dash/Activate()
-	dashing_item.attack_self(holder) //Used to toggle dash behavior in the dashing item
+	dashing_item.attack_self(owner) //Used to toggle dash behavior in the dashing item
 
 /datum/action/innate/dash/proc/Teleport(mob/user, atom/target)
 	if(!IsAvailable())
@@ -38,12 +36,12 @@
 			var/obj/spot2 = new phasein(get_turf(user), user.dir)
 			spot1.Beam(spot2,beam_effect,time=20)
 			current_charges--
-		holder.update_action_buttons_icon()
+		owner.update_action_buttons_icon()
 		addtimer(CALLBACK(src, PROC_REF(charge)), charge_rate)
 
 /datum/action/innate/dash/proc/charge()
 	current_charges = clamp(current_charges + 1, 0, max_charges)
-	holder.update_action_buttons_icon()
+	owner.update_action_buttons_icon()
 	if(recharge_sound)
 		playsound(dashing_item, recharge_sound, 50, 1)
-	to_chat(holder, "<span class='notice'>[src] now has [current_charges]/[max_charges] charges.</span>")
+	to_chat(owner, "<span class='notice'>[src] now has [current_charges]/[max_charges] charges.</span>")

code/datums/dna.dm

@@ -27,12 +27,16 @@
 /datum/dna/Destroy()
 	if(iscarbon(holder))
 		var/mob/living/carbon/cholder = holder
+		// We do this because a lot of stuff keeps references on species, for some reason.
+		species.on_species_loss(holder)
 		if(cholder.dna == src)
 			cholder.dna = null
 	holder = null
 
 	if(delete_species)
 		QDEL_NULL(species)
+	else
+		species = null
 
 	mutations.Cut()					//This only references mutations, just dereference.
 	temporary_mutations.Cut()		//^

code/datums/elements/photosynthesis.dm

@@ -39,12 +39,13 @@
 	attached_atoms[target]++
 
 /datum/element/photosynthesis/Detach(datum/target)
-	attached_atoms[target]--
-	if(!attached_atoms[target])
-		attached_atoms -= target
-		if(!length(attached_atoms))
-			STOP_PROCESSING(SSobj, src)
-			attached_atoms = null
+	if(LAZYLEN(attached_atoms))
+		attached_atoms[target]--
+		if(!attached_atoms[target])
+			attached_atoms -= target
+			if(!length(attached_atoms))
+				STOP_PROCESSING(SSobj, src)
+				attached_atoms = null
 	return ..()
 
 /datum/element/photosynthesis/process()

code/datums/mind.dm

@@ -81,13 +81,13 @@
 	var/list/ambitions
 //ambition end
 
-	///What character we spawned in as- either at roundstart or latejoin, so we know for persistent scars if we ended as the same person or not
-	var/mob/original_character
+	///Weakref to the character we spawned in as- either at roundstart or latejoin, so we know for persistent scars if we ended as the same person or not
+	var/datum/weakref/original_character
 
 	/// A lazy list of statuses to add next to this mind in the traitor panel
 	var/list/special_statuses
 
-/datum/mind/New(var/key)
+/datum/mind/New(key)
 	skill_holder = new(src)
 	src.key = key
 	soulOwner = src
@@ -95,15 +95,29 @@
 
 /datum/mind/Destroy()
 	SSticker.minds -= src
-	if(islist(antag_datums))
-		for(var/i in antag_datums)
-			var/datum/antagonist/antag_datum = i
-			if(antag_datum.delete_on_mind_deletion)
-				qdel(i)
-		antag_datums = null
+	QDEL_LIST(antag_datums)
+	QDEL_NULL(language_holder)
 	QDEL_NULL(skill_holder)
+	set_current(null)
+	soulOwner = null
 	return ..()
 
+/datum/mind/proc/set_current(mob/new_current)
+	if(new_current && QDELETED(new_current))
+		CRASH("Tried to set a mind's current var to a qdeleted mob, what the fuck")
+	if(current)
+		UnregisterSignal(src, COMSIG_PARENT_QDELETING)
+	current = new_current
+	if(current)
+		RegisterSignal(src, COMSIG_PARENT_QDELETING, PROC_REF(clear_current))
+
+/datum/mind/proc/clear_current(datum/source)
+	SIGNAL_HANDLER
+	set_current(null)
+
+/datum/mind/proc/set_original_character(new_original_character)
+	original_character = WEAKREF(new_original_character)
+
 /datum/mind/proc/get_language_holder()
 	if(!language_holder)
 		language_holder = new (src)
@@ -126,13 +140,13 @@
 		key = new_character.key
 
 	if(new_character.mind)								//disassociate any mind currently in our new body's mind variable
-		new_character.mind.current = null
+		new_character.mind.set_current(null)
 
 	var/datum/atom_hud/antag/hud_to_transfer = antag_hud//we need this because leave_hud() will clear this list
 	var/mob/living/old_current = current
 	if(current)
 		current.transfer_observers_to(new_character)	//transfer anyone observing the old character to the new one
-	current = new_character								//associate ourself with our new body
+	set_current(new_character)								//associate ourself with our new body
 	new_character.mind = src							//and associate our new body with ourself
 	for(var/a in antag_datums)	//Makes sure all antag datums effects are applied in the new body
 		var/datum/antagonist/A = a
@@ -1715,7 +1729,7 @@ GLOBAL_LIST(objective_choices)
 		SEND_SIGNAL(src, COMSIG_MOB_ON_NEW_MIND)
 	if(!mind.name)
 		mind.name = real_name
-	mind.current = src
+	mind.set_current(src)
 	mind.hide_ckey = client?.prefs?.hide_ckey
 
 /mob/living/carbon/mind_initialize()

code/datums/mutations/actions.dm

@@ -422,13 +422,13 @@
 	embedding = list("embedded_pain_multiplier" = 4, "embed_chance" = 100, "embedded_fall_chance" = 0)
 	w_class = WEIGHT_CLASS_SMALL
 	sharpness = SHARP_POINTY
-	var/mob/living/carbon/human/fired_by
+	var/datum/weakref/fired_by
 	/// if we missed our target
 	var/missed = TRUE
 
 /obj/item/hardened_spike/Initialize(mapload, firedby)
 	. = ..()
-	fired_by = firedby
+	fired_by = WEAKREF(firedby)
 	addtimer(CALLBACK(src, PROC_REF(checkembedded)), 5 SECONDS)
 
 /obj/item/hardened_spike/proc/checkembedded()
@@ -478,13 +478,16 @@
 		return
 	been_places = TRUE
 	chems = new
-	chems.transfered = embedded_mob
-	chems.spikey = src
-	to_chat(fired_by, "<span class='notice'>Link established! Use the \"Transfer Chemicals\" ability to send your chemicals to the linked target!</span>")
-	chems.Grant(fired_by)
+	chems.transfered = WEAKREF(embedded_mob)
+	var/mob/fired_by_mob = fired_by.resolve()
+	if(fired_by_mob)
+		to_chat(fired_by_mob, span_notice("Link established! Use the \"Transfer Chemicals\" ability to send your chemicals to the linked target!"))
+		chems.Grant(fired_by_mob)
 
 /obj/item/hardened_spike/chem/unembedded()
-	to_chat(fired_by, "<span class='warning'>Link lost!</span>")
+	var/mob/fired_by_mob = fired_by.resolve()
+	if(fired_by_mob)
+		to_chat(fired_by_mob, span_warning("Link lost!"))
 	QDEL_NULL(chems)
 	..()
 
@@ -496,19 +499,17 @@
 	name = "Transfer Chemicals"
 	desc = "Send all of your reagents into whomever the chem spike is embedded in. One use."
 	var/obj/item/hardened_spike/chem/spikey
-	var/mob/living/carbon/human/transfered
+	var/datum/weakref/transfered
 
 /datum/action/innate/send_chems/Activate()
-	if(!ishuman(transfered) || !ishuman(owner))
+	var/mob/living/carbon/human/transfered_mob = transfered?.resolve()
+	if(!ishuman(transfered_mob) || !ishuman(owner))
 		return
-	var/mob/living/carbon/human/transferer = owner
-
-	to_chat(transfered, "<span class='warning'>You feel a tiny prick!</span>")
-	transferer.reagents.trans_to(transfered, transferer.reagents.total_volume, 1, 1, 0)
+	to_chat(transfered_mob, span_warning("You feel a tiny prick!"))
+	owner.reagents.trans_to(transfered_mob, owner.reagents.total_volume, 1, 1, 0)
 
 	var/obj/item/bodypart/L = spikey.checkembedded()
 
 	//this is where it would deal damage, if it transfers chems it removes itself so no damage
 	spikey.forceMove(get_turf(L))
-	transfered.visible_message("<span class='notice'>[spikey] falls out of [transfered]!</span>")
-
+	transfered_mob.visible_message(span_notice("[spikey] falls out of [transfered_mob]!"))

code/datums/mutations/antenna.dm

@@ -28,8 +28,7 @@
 /datum/mutation/human/antenna/on_losing(mob/living/carbon/human/owner)
 	if(..())
 		return
-	if(linked_radio)
-		linked_radio.Destroy()
+	QDEL_NULL(linked_radio)
 
 /datum/mutation/human/antenna/New(class_ = MUT_OTHER, timer, datum/mutation/human/copymut)
 	..()

code/game/machinery/cryopod.dm

@@ -346,8 +346,10 @@ GLOBAL_LIST_EMPTY(cryopod_computers)
 	else
 		if(ishuman(mob_occupant))
 			var/mob/living/carbon/human/H = mob_occupant
-			if(H.mind && H.client && H.client.prefs && H == H.mind.original_character)
-				H.SaveTCGCards()
+			if(H.mind && H.client && H.client.prefs)
+				var/mob/living/carbon/human/H_original_character = H.mind.original_character?.resolve()
+				if(H_original_character && H == H_original_character)
+					H.SaveTCGCards()
 
 		var/list/gear = list()
 		if(iscarbon(mob_occupant))		// sorry simp-le-mobs deserve no mercy

code/modules/antagonists/blob/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(force, ...)
+	overmind = null
+	return ..()
+
 /datum/blobstrain/proc/on_gain()
 	overmind.color = complementary_color
 	for(var/BL in GLOB.blobs)

code/modules/antagonists/blob/blob/overmind.dm

@@ -177,6 +177,9 @@ GLOBAL_LIST_EMPTY(blob_nodes)
 	blob_mobs = null
 	resource_blobs = null
 	blobs_legit = null
+	blob_core = null
+	if(blobstrain)
+		QDEL_NULL(blobstrain)
 
 	SSshuttle.clearHostileEnvironment(src)
 	STOP_PROCESSING(SSobj, src)

code/modules/antagonists/cult/cult_items.dm

@@ -231,7 +231,7 @@
 	phaseout = /obj/effect/temp_visual/dir_setting/cult/phase/out
 
 /datum/action/innate/dash/cult/IsAvailable(silent = FALSE)
-	if(iscultist(holder) && current_charges)
+	if(iscultist(owner) && current_charges)
 		return TRUE
 	else
 		return FALSE

code/modules/awaymissions/corpse.dm

@@ -272,16 +272,26 @@
 
 //Non-human spawners
 
-/obj/effect/mob_spawn/AICorpse/create(ckey, name) //Creates a corrupted AI
-	var/A = locate(/mob/living/silicon/ai) in loc
-	if(A)
+/obj/effect/mob_spawn/AICorpse //Creates a corrupted AI
+	mob_type = /mob/living/silicon/ai/spawned
+
+/obj/effect/mob_spawn/AICorpse/create(ckey, name)
+	var/ai_already_present = locate(/mob/living/silicon/ai) in loc
+	if(ai_already_present)
+		qdel(src)
 		return
-	var/mob/living/silicon/ai/spawned/M = new(loc) //spawn new AI at landmark as var M
-	M.name = src.name
-	M.real_name = src.name
-	M.aiPDA.toff = TRUE //turns the AI's PDA messenger off, stopping it showing up on player PDAs
-	M.death() //call the AI's death proc
-	qdel(src)
+	. = ..()
+
+// TODO: Port the upstream tgstation rewrite of this.
+/obj/effect/mob_spawn/AICorpse/equip(mob/living/silicon/ai/ai)
+	. = ..()
+	if(!isAI(ai)) // This should never happen.
+		stack_trace("[type] spawned a mob of type [ai?.type || "NULL"] that was not an AI!")
+		return
+	ai.name = name
+	ai.real_name = name
+	ai.aiPDA.toff = TRUE //turns the AI's PDA messenger off, stopping it showing up on player PDAs
+	ai.death() //call the AI's death proc
 
 /obj/effect/mob_spawn/slime
 	mob_type = 	/mob/living/simple_animal/slime

code/modules/integrated_electronics/passive/power.dm

@@ -122,8 +122,9 @@
 				var/datum/reagent/blood/B = locate() in reagents.reagent_list
 				if(lfwb)
 					if(B && B.data["cloneable"])
-						var/mob/M = B.data["donor"]
-						if(M && (M.stat != DEAD) && (M.client))
+						var/datum/weakref/donor_ref = B.data["donor"]
+						var/mob/donor = donor_ref.resolve()
+						if(donor && (donor.stat != DEAD) && (donor.client))
 							bp = 500000
 				if((assembly.battery.maxcharge-assembly.battery.charge) / GLOB.CELLRATE > bp)
 					if(reagents.remove_reagent(/datum/reagent/blood, 1))

code/modules/mob/dead/new_player/login.dm

@@ -5,7 +5,7 @@
 	if(!mind)
 		mind = new /datum/mind(key)
 		mind.active = 1
-		mind.current = src
+		mind.set_current(src)
 
 	..()
 

code/modules/mob/dead/new_player/new_player.dm

@@ -695,7 +695,7 @@
 			mind.late_joiner = TRUE
 		mind.active = 0					//we wish to transfer the key manually
 		mind.transfer_to(H)					//won't transfer key since the mind is not active
-		mind.original_character = H
+		mind.set_original_character(H)
 
 	H.name = real_name
 	client.init_verbs()

code/modules/mob/living/blood.dm

@@ -185,7 +185,7 @@
 /mob/living/carbon/get_blood_data()
 	var/blood_data = list()
 	//set the blood data
-	blood_data["donor"] = src
+	blood_data["donor"] = WEAKREF(src)
 	blood_data["viruses"] = list()
 
 	for(var/thing in diseases)

code/modules/mob/living/brain/brain.dm

@@ -34,10 +34,11 @@
 		if(stat!=DEAD)	//If not dead.
 			death(1)	//Brains can die again. AND THEY SHOULD AHA HA HA HA HA HA
 		if(mind)	//You aren't allowed to return to brains that don't exist
-			mind.current = null
+			mind.set_current(null)
 			mind.active = FALSE		//No one's using it anymore.
 		ghostize()		//Ghostize checks for key so nothing else is necessary.
 	container = null
+	QDEL_NULL(stored_dna)
 	return ..()
 
 /mob/living/brain/update_mobility()

code/modules/mob/living/brain/brain_item.dm

@@ -282,6 +282,8 @@
 	if(brainmob)
 		QDEL_NULL(brainmob)
 	QDEL_LIST(traumas)
+	if(owner?.mind)
+		owner.mind.set_current(null)
 	return ..()
 
 //other types of brains

code/modules/mob/living/carbon/carbon.dm

@@ -17,7 +17,6 @@
 	QDEL_LIST(internal_organs)
 	QDEL_LIST(stomach_contents)
 	QDEL_LIST(bodyparts)
-	QDEL_LIST(implants)
 	hand_bodyparts = null		//Just references out bodyparts, don't need to delete twice.
 	remove_from_all_data_huds()
 	QDEL_NULL(dna)

code/modules/mob/living/carbon/human/species.dm

@@ -553,7 +553,7 @@ GLOBAL_LIST_EMPTY(roundstart_race_names)
 
 /datum/species/proc/on_species_loss(mob/living/carbon/human/C, datum/species/new_species, pref_load)
 	if(C.dna.species.exotic_bloodtype)
-		if(!new_species.exotic_bloodtype)
+		if(!new_species?.exotic_bloodtype)
 			C.dna.blood_type = random_blood_type()
 		else
 			C.dna.blood_type = new_species.exotic_bloodtype
@@ -573,7 +573,7 @@ GLOBAL_LIST_EMPTY(roundstart_race_names)
 		C.type_of_meat = initial(meat)
 
 	//If their inert mutation is not the same, swap it out
-	if((inert_mutation != new_species.inert_mutation) && LAZYLEN(C.dna.mutation_index) && (inert_mutation in C.dna.mutation_index))
+	if(new_species && (inert_mutation != new_species.inert_mutation) && LAZYLEN(C.dna.mutation_index) && (inert_mutation in C.dna.mutation_index))
 		C.dna.remove_mutation(inert_mutation)
 		//keep it at the right spot, so we can't have people taking shortcuts
 		var/location = C.dna.mutation_index.Find(inert_mutation)
@@ -582,7 +582,7 @@ GLOBAL_LIST_EMPTY(roundstart_race_names)
 		C.dna.mutation_index[new_species.inert_mutation] = create_sequence(new_species.inert_mutation)
 		C.dna.default_mutation_genes[new_species.inert_mutation] = C.dna.mutation_index[new_species.inert_mutation]
 
-	if(!new_species.has_field_of_vision && has_field_of_vision && ishuman(C) && CONFIG_GET(flag/use_field_of_vision))
+	if(new_species && !new_species.has_field_of_vision && has_field_of_vision && ishuman(C) && CONFIG_GET(flag/use_field_of_vision))
 		var/datum/component/field_of_vision/F = C.GetComponent(/datum/component/field_of_vision)
 		if(F)
 			qdel(F)

code/modules/mob/living/carbon/human/species_types/jellypeople.dm

@@ -320,17 +320,17 @@
 		L["name"] = body.name
 		L["ref"] = "[REF(body)]"
 		L["occupied"] = occupied
-		var/button
+		var/button_state
 		if(occupied == "owner")
-			button = "selected"
+			button_state = "selected"
 		else if(occupied == "stranger")
-			button = "danger"
+			button_state = "danger"
 		else if(can_swap(body))
-			button = null
+			button_state = null
 		else
-			button = "disabled"
+			button_state = "disabled"
 
-		L["swap_button_state"] = button
+		L["swap_button_state"] = button_state
 		L["swappable"] = (occupied == "available") && can_swap(body)
 
 		data["bodies"] += list(L)
@@ -745,9 +745,9 @@
 	background_icon_state = "bg_alien"
 	var/datum/species/jelly/stargazer/species
 
-/datum/action/innate/link_minds/New(_species)
+/datum/action/innate/link_minds/New(species)
 	..()
-	species = _species
+	src.species = species
 
 /datum/action/innate/link_minds/Activate()
 	var/mob/living/carbon/human/H = owner
@@ -771,3 +771,7 @@
 		else
 			to_chat(H, "<span class='warning'>You can't seem to link [target]'s mind...</span>")
 			to_chat(target, "<span class='warning'>The foreign presence leaves your mind.</span>")
+
+/datum/action/innate/link_minds/Destroy()
+	species = null
+	return ..()

code/modules/mob/living/living.dm

@@ -35,8 +35,10 @@
 	if(buckled)
 		buckled.unbuckle_mob(src,force=1)
 	QDEL_LIST_ASSOC_VAL(ability_actions)
-
+	QDEL_LIST(abilities)
+	QDEL_LIST(implants)
 	remove_from_all_data_huds()
+	cleanse_trait_datums()
 	GLOB.mob_living_list -= src
 	QDEL_LIST(diseases)
 	return ..()
@@ -909,7 +911,7 @@
 	else
 		throw_alert("gravity", /atom/movable/screen/alert/weightless)
 	if(!override && !is_flying())
-		INVOKE_ASYNC(src, TYPE_PROC_REF(/atom/movable, float), !has_gravity)
+		float(!has_gravity)
 
 /mob/living/float(on)
 	if(throwing)

code/modules/mob/living/silicon/ai/ai.dm

@@ -100,7 +100,9 @@
 	var/display_icon_override
 	var/emote_display = "Neutral" //text string of the current emote we set for the status displays, to prevent logins resetting it.
 
+	// TODO: Currently unused, needs port from TG.
 	var/datum/robot_control/robot_control
+	// TODO: Currently unused, needs port from TG.
 	/// Station alert datum for showing alerts UI
 	var/datum/station_alert/alert_control
 	///remember AI's last location
@@ -119,7 +121,7 @@
 		new/obj/structure/ai_core/deactivated(loc) //New empty terminal.
 		return INITIALIZE_HINT_QDEL //Delete AI.
 
-	ADD_TRAIT(src, TRAIT_NO_TELEPORT, src)
+	ADD_TRAIT(src, TRAIT_NO_TELEPORT, INNATE_TRAIT)
 	if(L && istype(L, /datum/ai_laws))
 		laws = L
 		laws.associate(src)
@@ -189,20 +191,34 @@
 	GLOB.ai_list -= src
 	GLOB.shuttle_caller_list -= src
 	SSshuttle.autoEvac()
+	stop_controlling_display()
 	QDEL_NULL(eyeobj) // No AI, no Eye
 	QDEL_NULL(spark_system)
+	QDEL_NULL(deploy_action)
+	QDEL_NULL(redeploy_action)
+	QDEL_NULL(custom_holoform)
+	QDEL_NULL(master_multicam)
+	deployed_shell = null
+	parent = null
+	QDEL_NULL(spark_system)
 	QDEL_NULL(malf_picker)
 	QDEL_NULL(doomsday_device)
-	// TODO: Why these no work?
+	// TODO: Port implementation of these from TG or remove the unused code.
 	// QDEL_NULL(robot_control)
-	QDEL_NULL(aiMulti)
 	// QDEL_NULL(alert_control)
+	QDEL_NULL(aiMulti)
+	QDEL_NULL(aiPDA)
 	malfhack = null
 	current = null
 	Bot = null
 	controlled_equipment = null
 	linked_core = null
 	apc_override = null
+	for(var/mob/living/silicon/robot/linked_robot as anything in connected_robots)
+		if(QDELETED(linked_robot))
+			continue
+		linked_robot.set_connected_ai(null)
+	connected_robots.Cut()
 	return ..()
 
 /mob/living/silicon/ai/IgniteMob()
@@ -357,12 +373,12 @@
 		is_anchored = !is_anchored
 		move_resist = MOVE_FORCE_NORMAL
 		status_flags |= CANPUSH
-		REMOVE_TRAIT(src, TRAIT_NO_TELEPORT, src)
+		REMOVE_TRAIT(src, TRAIT_NO_TELEPORT, INNATE_TRAIT)
 	else
 		is_anchored = !is_anchored
 		move_resist = MOVE_FORCE_OVERPOWERING
 		status_flags &= ~CANPUSH
-		ADD_TRAIT(src, TRAIT_NO_TELEPORT, src)
+		ADD_TRAIT(src, TRAIT_NO_TELEPORT, INNATE_TRAIT)
 
 /mob/living/silicon/ai/proc/ai_mob_to_structure()
 	disconnect_shell()
@@ -1097,6 +1113,10 @@
 	else
 		Remove(owner) //If the last shell is blown, destroy it.
 
+/datum/action/innate/deploy_last_shell/Destroy()
+	last_used_shell = null
+	return ..()
+
 /mob/living/silicon/ai/proc/disconnect_shell()
 	if(deployed_shell) //Forcibly call back AI in event of things such as damage, EMP or power loss.
 		to_chat(src, "<span class='danger'>Your remote connection has been reset!</span>")
@@ -1107,9 +1127,7 @@
 	return
 
 /mob/living/silicon/ai/spawned/Initialize(mapload, datum/ai_laws/L, mob/target_ai)
-	. = ..()
-	if(!target_ai)
-		target_ai = src //cheat! just give... ourselves as the spawned AI, because that's technically correct
+	. = ..(mapload, L, src) //cheat! just give... ourselves as the spawned AI, because that's technically correct
 
 /mob/living/silicon/ai/proc/camera_visibility(mob/camera/aiEye/moved_eye)
 	GLOB.cameranet.visibility(moved_eye, client, all_eyes, USE_STATIC_OPAQUE)

code/modules/mob/living/silicon/pai/pai.dm

@@ -57,7 +57,6 @@
 	var/encryptmod = FALSE
 	var/holoform = FALSE
 	var/canholo = TRUE
-	var/obj/item/card/id/access_card = null
 	var/chassis = "repairbot"
 	var/dynamic_chassis
 	var/dynamic_chassis_sit = FALSE			//whether we're sitting instead of resting spritewise
@@ -85,13 +84,21 @@
 	var/icon/custom_holoform_icon
 
 /mob/living/silicon/pai/Destroy()
+	QDEL_NULL(signaler)
+	QDEL_NULL(pda)
 	QDEL_NULL(internal_instrument)
+	if(cable)
+		QDEL_NULL(cable)
+	hackdoor = null
 	if (loc != card)
 		card.forceMove(drop_location())
 	card.pai = null
 	card.cut_overlays()
 	card.add_overlay("pai-off")
+	card = null
+	current = null
 	GLOB.pai_list -= src
+	STOP_PROCESSING(SSfastprocess, src)
 	return ..()
 
 /mob/living/silicon/pai/Initialize(mapload)

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

@@ -401,22 +401,16 @@
 	buttontooltipstyle = "cult"
 	button_icon_state = "cult_mark"
 	var/tracking = FALSE
-	var/mob/living/simple_animal/hostile/construct/the_construct
-
-
-/datum/action/innate/seek_master/Grant(var/mob/living/C)
-	the_construct = C
-	..()
 
 /datum/action/innate/seek_master/Activate()
 	var/datum/antagonist/cult/C = owner.mind.has_antag_datum(/datum/antagonist/cult)
 	if(!C)
 		return
 	if(!C.cult_team)
-		to_chat(the_construct, "<span class='cult italic'>You are alone, and have no team.</span>")
+		to_chat(owner, "<span class='cult italic'>You are alone, and have no team.</span>")
 		return
 	var/datum/objective/eldergod/summon_objective = locate() in C.cult_team.objectives
-
+	var/mob/living/simple_animal/hostile/construct/the_construct = owner
 	if(summon_objective.check_completion())
 		the_construct.master = C.cult_team.blood_target
 
@@ -442,15 +436,11 @@
 	background_icon_state = "bg_demon"
 	buttontooltipstyle = "cult"
 	button_icon_state = "cult_mark"
-	var/mob/living/simple_animal/hostile/construct/harvester/the_construct
-
-/datum/action/innate/seek_prey/Grant(var/mob/living/C)
-	the_construct = C
-	..()
 
 /datum/action/innate/seek_prey/Activate()
 	if(GLOB.cult_narsie == null)
 		return
+	var/mob/living/simple_animal/hostile/construct/the_construct = owner
 	if(the_construct.seeking)
 		desc = "None can hide from Nar'Sie, activate to track a survivor attempting to flee the red harvest!"
 		button_icon_state = "cult_mark"

code/modules/mob/living/simple_animal/hostile/mining_mobs/elites/elite.dm

@@ -35,6 +35,10 @@
 		var/datum/action/innate/elite_attack/attack_action = new action_type()
 		attack_action.Grant(src)
 
+/mob/living/simple_animal/hostile/asteroid/elite/Destroy(force, ...)
+	owner = null
+	return ..()
+
 //Prevents elites from attacking members of their faction (can't hurt themselves either) and lets them mine rock with an attack despite not being able to smash walls.
 /mob/living/simple_animal/hostile/asteroid/elite/AttackingTarget()
 	if(istype(target, /mob/living/simple_animal/hostile))

code/modules/mob/mob.dm

@@ -20,27 +20,38 @@
 	hook_vr("mob_new",list(src))
 
 /mob/Destroy()//This makes sure that mobs with clients/keys are not just deleted from the game.
+	// if(client)
+	// 	stack_trace("Mob with client has been deleted.")
+	// else if(ckey)
+	// 	stack_trace("Mob without client but with associated ckey, [ckey], has been deleted.")
+	unset_machine()
 	remove_from_mob_list()
 	remove_from_dead_mob_list()
 	remove_from_alive_mob_list()
+	QDEL_LIST(mob_spell_list)
+	QDEL_LIST(actions)
 	GLOB.all_clockwork_mobs -= src
+	// remove_from_mob_suicide_list()
 	focus = null
 	LAssailant = null
 	movespeed_modification = 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)
 	dispose_rendering()
 	qdel(hud_used)
-	for(var/cc in client_colours)
-		qdel(cc)
-	client_colours = null
-	ghostize()
-	..()
-	return QDEL_HINT_HARDDEL
+	QDEL_LIST(client_colours)
+	ghostize(can_reenter_corpse = FALSE) //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.set_current(null)
+	// if(mock_client)
+	//	mock_client.mob = null
+	return ..()
 
 /mob/GenerateTag()
 	tag = "mob_[next_mob_id++]"

code/modules/shuttle/arrivals.dm

@@ -33,6 +33,14 @@
 		WARNING("More than one arrivals docking_port placed on map! Ignoring duplicates.")
 	SSshuttle.arrivals = src
 
+/obj/docking_port/mobile/arrivals/proc/on_console_deleted(datum/source)
+	SIGNAL_HANDLER
+	console = null
+	for(var/obj/machinery/requests_console/new_console as anything in GLOB.allConsoles)
+		var/area/console_area = get_area(new_console)
+		if(istype(console_area, /area/shuttle/arrival) && !QDELETED(new_console) && new_console != source)
+			console = new_console
+
 /obj/docking_port/mobile/arrivals/LateInitialize()
 	areas = list()
 
@@ -40,10 +48,18 @@
 	for(var/area/shuttle/arrival/A in GLOB.sortedAreas)
 		for(var/obj/structure/chair/C in A)
 			new_latejoin += C
-		if(!console)
-			console = locate(/obj/machinery/requests_console) in A
 		areas += A
 
+	if(!console)
+		for(var/obj/machinery/requests_console/new_console as anything in GLOB.allConsoles)
+			var/area/console_area = get_area(new_console)
+			if(!istype(console_area, /area/shuttle/arrival) || QDELETED(new_console))
+				continue
+			console = new_console
+			RegisterSignal(console, COMSIG_PARENT_QDELETING, PROC_REF(on_console_deleted))
+	else if(istype(console))
+		RegisterSignal(console, COMSIG_PARENT_QDELETING, PROC_REF(on_console_deleted))
+
 	if(SSjob.latejoin_trackers.len)
 		WARNING("Map contains predefined latejoin spawn points and an arrivals shuttle. Using the arrivals shuttle.")
 

code/modules/shuttle/shuttle.dm

@@ -941,13 +941,19 @@
 
 /obj/docking_port/mobile/proc/count_engines()
 	. = 0
+	engine_list = list()
 	for(var/thing in shuttle_areas)
 		var/area/shuttle/areaInstance = thing
 		for(var/obj/structure/shuttle/engine/E in areaInstance.contents)
 			if(!QDELETED(E))
 				engine_list += E
+				RegisterSignal(E, COMSIG_PARENT_QDELETING, PROC_REF(on_engine_deleted))
 				. += E.engine_power
 
+/obj/docking_port/mobile/proc/on_engine_deleted(datum/source)
+	SIGNAL_HANDLER
+	engine_list -= source
+
 // Double initial engines to get to 0.5 minimum
 // Lose all initial engines to get to 2
 //For 0 engine shuttles like BYOS 5 engines to get to doublespeed

code/modules/shuttle/shuttle_creation/shuttle_creator.dm

@@ -198,8 +198,8 @@ GLOBAL_LIST_EMPTY(custom_shuttle_machines)		//Machines that require updating (He
 	var/invertedDir = invertDir(portDirection)
 	if(!portDirection || !invertedDir)
 		to_chat(usr, "<span class='warning'>Shuttle creation aborted, docking airlock must be on an external wall. Please select a new airlock.</span>")
-		port.Destroy()
-		stationary_port.Destroy()
+		QDEL_NULL(port)
+		QDEL_NULL(stationary_port)
 		linkedShuttleId = null
 		return FALSE
 	port.dir = invertedDir
@@ -207,8 +207,8 @@ GLOBAL_LIST_EMPTY(custom_shuttle_machines)		//Machines that require updating (He
 
 	if(!calculate_bounds(port))
 		to_chat(usr, "<span class='warning'>Bluespace calculations failed, please select a new airlock.</span>")
-		port.Destroy()
-		stationary_port.Destroy()
+		QDEL_NULL(port)
+		QDEL_NULL(stationary_port)
 		linkedShuttleId = null
 		return FALSE
 

code/modules/spells/spell_types/ethereal_jaunt.dm

@@ -39,7 +39,7 @@
 		return
 	mobloc = get_turf(target.loc)
 	jaunt_steam(mobloc)
-	ADD_TRAIT(target, TRAIT_MOBILITY_NOMOVE, src)
+	ADD_TRAIT(target, TRAIT_MOBILITY_NOMOVE, MAGIC_TRAIT)
 	target.update_mobility()
 	holder.reappearing = 1
 	play_sound("exit",target)
@@ -55,7 +55,7 @@
 				if(T)
 					if(target.Move(T))
 						break
-		REMOVE_TRAIT(target, TRAIT_MOBILITY_NOMOVE, src)
+		REMOVE_TRAIT(target, TRAIT_MOBILITY_NOMOVE, MAGIC_TRAIT)
 		target.update_mobility()
 
 /obj/effect/proc_holder/spell/targeted/ethereal_jaunt/proc/jaunt_steam(mobloc)

code/modules/unit_tests/vore_tests.dm

@@ -97,8 +97,8 @@
 	endOxyloss = prey.getOxyLoss()
 	if(startOxyloss < endOxyloss)
 		Fail("Prey takes oxygen damage in a pred's belly! (Before: [startOxyloss]; after: [endOxyloss])")
-	qdel(prey)
-	qdel(pred)
+	QDEL_NULL(prey)
+	QDEL_NULL(pred)
 	return TRUE
 ////////////////////////////////////////////////////////////////
 /datum/unit_test/belly_spacesafe
@@ -160,8 +160,8 @@
 	endBruteloss = prey.getBruteLoss()
 	if(startBruteloss < endBruteloss)
 		Fail("Prey takes brute damage in space! (Before: [startBruteloss]; after: [endBruteloss])")
-	qdel(prey)
-	qdel(pred)
+	QDEL_NULL(prey)
+	QDEL_NULL(pred)
 	return TRUE
 ////////////////////////////////////////////////////////////////
 /datum/unit_test/belly_damage
@@ -213,6 +213,6 @@
 	endBruteBurn = prey.getBruteLoss() + prey.getFireLoss()
 	if(startBruteBurn >= endBruteBurn)
 		Fail("Prey doesn't take damage in digesting belly! (Before: [startBruteBurn]; after: [endBruteBurn])")
-	qdel(prey)
-	qdel(pred)
+	QDEL_NULL(prey)
+	QDEL_NULL(pred)
 	return TRUE

code/modules/vehicles/mecha/combat/neovgre.dm

@@ -53,7 +53,8 @@
 
 /obj/vehicle/sealed/mecha/combat/neovgre/proc/go_critical()
 	explosion(get_turf(loc), 3, 5, 10, 20, 30)
-	Destroy(src)
+	if(!QDELETED(src))
+		qdel(src)
 
 /obj/vehicle/sealed/mecha/combat/neovgre/container_resist(mob/living/user)
 	to_chat(user, "<span class='brass'>Neovgre requires a lifetime commitment friend, no backing out now!</span>")

code/modules/zombie/organs.dm

@@ -28,11 +28,10 @@
 	START_PROCESSING(SSobj, src)
 
 /obj/item/organ/zombie_infection/Remove(special = FALSE)
-	if(owner)
-		if(iszombie(owner) && old_species)
-			owner.set_species(old_species)
-		if(timer_id)
-			deltimer(timer_id)
+	if(!QDELETED(owner) && iszombie(owner) && old_species)
+		owner.set_species(old_species)
+	if(timer_id)
+		deltimer(timer_id)
 	. = ..()
 	STOP_PROCESSING(SSobj, src) //Required to be done after the parent call to avoid conflicts with organ decay.