[MIRROR] Adds collapsing stone tiles (#1933)

* Adds collapsing stone tiles

* Update necropolis_gate.dm

* Update necropolis_gate.dm.rej

* Delete necropolis_gate.dm.rej

code/game/turfs/simulated/chasm.dm

@@ -65,6 +65,9 @@
 	//if anything matching this typecache is found in the chasm, we don't drop things
 	var/static/list/chasm_safeties_typecache = typecacheof(list(/obj/structure/lattice/catwalk, /obj/structure/stone_tile))
 	var/list/found_safeties = typecache_filter_list(contents, chasm_safeties_typecache)
+	for(var/obj/structure/stone_tile/S in found_safeties)
+		if(S.fallen)
+			LAZYREMOVE(found_safeties, S)
 	return LAZYLEN(found_safeties)
 
 /turf/open/chasm/proc/drop_stuff(AM)
@@ -89,6 +92,8 @@
 	if(istype(AM, /obj/effect/portal))
 		//Portals aren't affected by gravity. Probably.
 		return FALSE
+	if(istype(AM, /obj/structure/stone_tile))
+		return FALSE
 	//Flies right over the chasm
 	if(isliving(AM))
 		var/mob/M = AM
@@ -204,4 +209,4 @@
 /turf/open/chasm/straight_down/jungle
 	icon = 'icons/turf/floors/junglechasm.dmi'
 	planetary_atmos = TRUE
-	initial_gas_mix = LAVALAND_DEFAULT_ATMOS
+	initial_gas_mix = LAVALAND_DEFAULT_ATMOS

code/game/turfs/simulated/floor/plating/lava.dm

@@ -62,6 +62,9 @@
 	//if anything matching this typecache is found in the lava, we don't burn things
 	var/static/list/lava_safeties_typecache = typecacheof(list(/obj/structure/lattice/catwalk, /obj/structure/stone_tile))
 	var/list/found_safeties = typecache_filter_list(contents, lava_safeties_typecache)
+	for(var/obj/structure/stone_tile/S in found_safeties)
+		if(S.fallen)
+			LAZYREMOVE(found_safeties, S)
 	return LAZYLEN(found_safeties)