Somewhat cursed lateload z-level minimap hard del fix (#14017)

* dumb test fix

* Ivan's fixes as well

* wrong place for unregister

* wuh

* just in case

* this is dumb

* some more comment

* general cleanup

code/controllers/subsystem/minimaps.dm

@@ -36,7 +36,7 @@ SUBSYSTEM_DEF(minimaps)
 	///assoc list of hash = image of images drawn by players
 	var/list/image/drawn_images = list()
 	///list of callbacks we need to invoke late because Initialize happens early, or a Z-level was loaded after init
-	var/list/datum/callback/earlyadds = list()
+	var/list/list/datum/callback/earlyadds = list()
 	///assoc list of minimap objects that are hashed so we have to update as few as possible
 	var/list/hashed_minimaps = list()
 
@@ -138,8 +138,8 @@ SUBSYSTEM_DEF(minimaps)
 	if(!earlyadds["[level]"])
 		return
 
-	for(var/i=1 to length(earlyadds["[level]"]))
-		earlyadds["[level]"][i].Invoke()
+	for(var/datum/callback/callback AS in earlyadds["[level]"])
+		callback.Invoke()
 	earlyadds["[level]"] = null //then clear them
 
 /**
@@ -223,9 +223,8 @@ SUBSYSTEM_DEF(minimaps)
 		CRASH("Invalid marker added to subsystem")
 
 	if(!initialized || !(minimaps_by_z["[target.z]"])) //the minimap doesn't exist yet, z level was probably loaded after init
-		if(!(earlyadds["[target.z]"]))
-			earlyadds["[target.z]"] = list()
-		earlyadds["[target.z]"] += CALLBACK(src, PROC_REF(add_marker), target, hud_flags, blip)
+		LAZYADDASSOC(earlyadds, "[target.z]", CALLBACK(src, PROC_REF(add_marker), target, hud_flags, blip))
+		RegisterSignal(target, COMSIG_QDELETING, PROC_REF(remove_earlyadd), override = TRUE) //Override required for late z-level loading to prevent hard dels where an atom is initiated during z load, but is qdel'd before it finishes
 		return
 
 	var/turf/target_turf = get_turf(target)
@@ -244,7 +243,18 @@ SUBSYSTEM_DEF(minimaps)
 		RegisterSignal(target, COMSIG_MOVABLE_Z_CHANGED, PROC_REF(on_z_change))
 		blip.RegisterSignal(target, COMSIG_MOVABLE_MOVED, TYPE_PROC_REF(/image, minimap_on_move))
 	removal_cbs[target] = CALLBACK(src, PROC_REF(removeimage), blip, target, hud_flags)
-	RegisterSignal(target, COMSIG_QDELETING, PROC_REF(remove_marker))
+	RegisterSignal(target, COMSIG_QDELETING, PROC_REF(remove_marker), override = TRUE) //override for atoms that were on a late loaded z-level, overrides the remove_earlyadd above
+
+///Removes the object from the earlyadds list, in case it was qdel'd before the z-level was fully loaded
+/datum/controller/subsystem/minimaps/proc/remove_earlyadd(atom/source)
+	SIGNAL_HANDLER
+	remove_marker(source)
+	for(var/datum/callback/callback in earlyadds["[source.z]"])
+		if(callback.arguments[1] != source)
+			continue
+		earlyadds["[source.z]"] -= callback
+		UnregisterSignal(source, COMSIG_QDELETING)
+		return
 
 /**
  * removes an image from raw tracked lists, invoked by callback

code/modules/vehicles/unmanned/unmanned_vehicle.dm

@@ -74,9 +74,10 @@
 	SSminimaps.add_marker(src, MINIMAP_FLAG_MARINE, image('icons/UI_icons/map_blips.dmi', null, "uav"))
 
 /obj/vehicle/unmanned/Destroy()
-	. = ..()
 	GLOB.unmanned_vehicles -= src
 	QDEL_NULL(flash)
+	QDEL_NULL(in_chamber)
+	return ..()
 
 /obj/vehicle/unmanned/obj_destruction()
 	robogibs(src)