Lighting fix

code/modules/lighting/lighting_corner.dm

@@ -86,13 +86,14 @@ GLOBAL_LIST_INIT(LIGHTING_CORNER_DIAGONAL, list(NORTHEAST, SOUTHEAST, SOUTHWEST,
 
 // God that was a mess, now to do the rest of the corner code! Hooray!
 /datum/lighting_corner/proc/update_lumcount(var/delta_r, var/delta_g, var/delta_b)
+
+	if ((abs(delta_r)+abs(delta_g)+abs(delta_b)) == 0)
+		return
+
 	lum_r += delta_r
 	lum_g += delta_g
 	lum_b += delta_b
 
-	if ((delta_r+delta_g+delta_b) == 0)
-		return
-
 	if (!needs_update)
 		needs_update = TRUE
 		GLOB.lighting_update_corners += src