default: add mossystone and mossystonebrick

mods/default/functions.lua

@@ -429,14 +429,18 @@ minetest.register_abm({
 
 minetest.register_abm({
 	label = "Moss growth",
-	nodenames = {"default:cobble", "stairs:slab_cobble", "stairs:stair_cobble"},
+	nodenames = {"default:cobble", "default:stonebrick", "stairs:slab_cobble", "stairs:stair_cobble"},
 	neighbors = {"group:water"},
 	interval = 16,
 	chance = 200,
 	catch_up = false,
 	action = function(pos, node)
-		if node.name == "default:cobble" then
+        if node.name == "default:stone" then
+            minetest.set_node(pos, {name = "default:mossystone"})
+        elseif node.name == "default:cobble" then
 			minetest.set_node(pos, {name = "default:mossycobble"})
+        elseif node.name == "default:stonebrick" then
+            minetest.set_node(pos, {name = "default:mossystonebrick"})
 		elseif node.name == "stairs:slab_cobble" then
 			minetest.set_node(pos, {name = "stairs:slab_mossycobble", param2 = node.param2})
 		elseif node.name == "stairs:stair_cobble" then

mods/default/nodes.lua

@@ -220,6 +220,14 @@ minetest.register_node("default:stone_block", {
 	sounds = default.node_sound_stone_defaults(),
 })
 
+minetest.register_node("default:mossystone", {
+	description = "Mossy Stone",
+	tiles = {"default_mossystone.png"},
+	is_ground_content = false,
+	groups = {cracky = 3, stone = 1},
+	sounds = default.node_sound_stone_defaults(),
+})
+
 minetest.register_node("default:mossycobble", {
 	description = "Mossy Cobblestone",
 	tiles = {"default_mossycobble.png"},
@@ -228,6 +236,13 @@ minetest.register_node("default:mossycobble", {
 	sounds = default.node_sound_stone_defaults(),
 })
 
+minetest.register_node("default:mossystonebrick", {
+	description = "Mossy Stonebrick",
+	tiles = {"default_mossystone_brick.png"},
+	is_ground_content = false,
+	groups = {cracky = 3, stone = 1},
+	sounds = default.node_sound_stone_defaults(),
+})
 
 minetest.register_node("default:desert_stone", {
 	description = "Desert Stone",