Merge pull request #3249 from Citadel-Station-13/upstream-merge-31412

[MIRROR] Stops airlocks from getting harddeleted, also fixes an unrelated runtime

code/game/machinery/doors/airlock.dm

@@ -234,6 +234,8 @@
 		for(var/obj/machinery/doorButtons/D in GLOB.machines)
 			D.removeMe(src)
 	qdel(note)
+	var/datum/atom_hud/data/diagnostic/diag_hud = GLOB.huds[DATA_HUD_DIAGNOSTIC]
+	diag_hud.remove_from_hud(src)
 	return ..()
 
 /obj/machinery/door/airlock/handle_atom_del(atom/A)

code/game/objects/obj_defense.dm

@@ -52,10 +52,12 @@
 		return
 	..() //contents explosion
 	if(target == src)
+		obj_integrity = 0
 		qdel(src)
 		return
 	switch(severity)
 		if(1)
+			obj_integrity = 0
 			qdel(src)
 		if(2)
 			take_damage(rand(100, 250), BRUTE, "bomb", 0)