TG: Sanity checks, miscellaneous bugfixes, failsafes.

Disposals no longer indiscriminately let items land inside it - the items have
to have been thrown by someone.

The ongoing attempt to fix the thousands of runtimes plaguing the game.
Revision: r3195
Author: 	 vageyenaman

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

@@ -1860,8 +1860,9 @@ It can still be worn/put on as normal.
 				if (W)
 					W.loc = target.loc
 					W.dropped(target)
-					W.layer = initial(W.layer)
-				W.add_fingerprint(source)
+					if (W)
+						W.layer = initial(W.layer)
+						W.add_fingerprint(source)
 			else
 				if(!item) return
 				if (istype(item, /obj/item/clothing/mask))

code/modules/recycling/disposal.dm

@@ -477,12 +477,10 @@
 			del(H)
 
 	CanPass(atom/movable/mover, turf/target, height=0, air_group=0)
-		if (istype(mover,/obj/item))
+		if (istype(mover,/obj/item) && mover.throwing)
 			var/obj/item/I = mover
 			if(istype(I, /obj/item/weapon/dummy) || istype(I, /obj/item/projectile))
 				return
-			if(!mover.throwing)
-				return ..()
 			if(prob(75))
 				I.loc = src
 				for(var/mob/M in viewers(src))