Make mapgen work again

src/mapgen.lua

@@ -12,9 +12,10 @@ saplings grow into trees. --]]
 
 -- Part 1: To disable the mapgen, add the *starting* comment under this line.
 
+local perlin_scale, nosmooth_rarity
 if not snow.disable_mapgen then
 	print("[snow] Mapgen enabled!")
-	
+
 	snow.mapgen = snow.mapgen or {}
 	local mg = snow.mapgen
 
@@ -27,7 +28,6 @@ if not snow.disable_mapgen then
 	local size = snow.mapgen_size
 	local smooth = snow.smooth_biomes
 
-	local nosmooth_rarity, perlin_scale
 	local function calc_values()
 		nosmooth_rarity = 1-rarity/50
 		perlin_scale = size*100/rarity

src/mapgen_v6.lua

@@ -142,10 +142,10 @@ local function define_contents()
 end
 
 local smooth = snow.smooth_biomes
-local smooth_rarity_max = mg.smooth_rarity_max or 0
-local smooth_rarity_min = mg.smooth_rarity_min or 0
-local smooth_rarity_dif = mg.smooth_rarity_dif or 0
-local nosmooth_rarity = mg.nosmooth_rarity or 0
+local smooth_rarity_max = mg.smooth_rarity_max
+local smooth_rarity_min = mg.smooth_rarity_min
+local smooth_rarity_dif = mg.smooth_rarity_dif
+local nosmooth_rarity = mg.nosmooth_rarity
 
 snow.register_on_configuring(function(name, v)
 	if name == "debug" then
@@ -235,7 +235,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	for z = z0, z1 do
 	for x = x0, x1 do
 		local in_biome = false
-		local test = 0
+		local test
 		if nvals_default[ni] < 0.35 then
 			nvals_cold = nvals_cold or perlin_objs.cold:get2dMap_flat({x=x0, y=z0}, nbuf_cold)
 			test = math.min(nvals_cold[ni], 1)