From 741da037fb812de1c6ccbfea39b1544a5351578b Mon Sep 17 00:00:00 2001
From: Tigercat2000 <nick.pilant2@gmail.com>
Date: Mon, 11 May 2015 19:37:15 -0700
Subject: [PATCH] Prevent divide by 0 runtime, fix supply shuttle

This commit adds a small sanity check to the falloff calculations of
lights, to prevent them from dividing by 0. This may cause undiscovered
strangeness, but strangeness is better than filling the runtime log.

This commit also fixes the supply shuttle, which was not spawning any
ordered items. It did this because it had a very basic contents.len check
which the lighting overlays triggered. The sanity check to not spawn stuff
on top of other stuff is now a for(atom) loop on the turfs, which has
snowflake checks for lights and lighting overlays.
---
 code/game/supplyshuttle.dm            | 10 +++++++++-
 code/modules/lighting/light_source.dm |  8 ++++----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/code/game/supplyshuttle.dm b/code/game/supplyshuttle.dm
index 3331861c136..a64e798c3ec 100644
--- a/code/game/supplyshuttle.dm
+++ b/code/game/supplyshuttle.dm
@@ -238,7 +238,15 @@ var/list/mechtoys = list(
 		var/list/clear_turfs = list()
 
 		for(var/turf/T in area_shuttle)
-			if(T.density || T.contents.len)	continue
+			if(T.density)	continue
+			var/contcount
+			for(var/atom/A in T.contents)
+				if(istype(A,/atom/movable/lighting_overlay))
+					continue
+				if(istype(A,/obj/machinery/light))
+					continue
+				contcount++
+			if(contcount)	continue
 			clear_turfs += T
 
 		for(var/S in shoppinglist)
diff --git a/code/modules/lighting/light_source.dm b/code/modules/lighting/light_source.dm
index 41c66359671..35bd0db7323 100644
--- a/code/modules/lighting/light_source.dm
+++ b/code/modules/lighting/light_source.dm
@@ -120,9 +120,9 @@
    #endif
 
    #if LIGHTING_LAMBERTIAN == 1
-	. = CLAMP01((1 - CLAMP01(sqrt(.) / light_range)) * (1 / (sqrt(. + 1))))
+	. = CLAMP01((1 - CLAMP01(sqrt(.) / max(1,light_range))) * (1 / (sqrt(. + 1))))
    #else
-	. = 1 - CLAMP01(sqrt(.) / light_range)
+	. = 1 - CLAMP01(sqrt(.) / max(1,light_range))
    #endif
 
   #elif LIGHTING_FALLOFF == 2 // square
@@ -133,9 +133,9 @@
    #endif
 
    #if LIGHTING_LAMBERTIAN == 1
-	. = CLAMP01((1 - CLAMP01(. / light_range)) * (1 / (sqrt(.)**2 + )))
+	. = CLAMP01((1 - CLAMP01(. / max(1,light_range))) * (1 / (sqrt(.)**2 + )))
    #else
-	. = 1 - CLAMP01(. / light_range)
+	. = 1 - CLAMP01(. / max(1,light_range))
    #endif
   #endif