Rainforest: Add emergent jungle tree and sapling

Height 20 to 32 nodes.
Dependent on chunksize >= 5.
Base limited to maximum altitude y = 32.
Craft sapling from 9 jungle saplings.

mods/default/nodes.lua

@@ -80,6 +80,7 @@ default:jungletree
 default:junglewood
 default:jungleleaves
 default:junglesapling
+default:emergent_jungle_sapling
 
 default:pine_tree
 default:pine_wood
@@ -775,6 +776,41 @@ minetest.register_node("default:junglesapling", {
 	end,
 })
 
+minetest.register_node("default:emergent_jungle_sapling", {
+	description = "Emergent Jungle Tree Sapling",
+	drawtype = "plantlike",
+	tiles = {"default_emergent_jungle_sapling.png"},
+	inventory_image = "default_emergent_jungle_sapling.png",
+	wield_image = "default_emergent_jungle_sapling.png",
+	paramtype = "light",
+	sunlight_propagates = true,
+	walkable = false,
+	on_timer = default.grow_sapling,
+	selection_box = {
+		type = "fixed",
+		fixed = {-4 / 16, -0.5, -4 / 16, 4 / 16, 7 / 16, 4 / 16}
+	},
+	groups = {snappy = 2, dig_immediate = 3, flammable = 2,
+		attached_node = 1, sapling = 1},
+	sounds = default.node_sound_leaves_defaults(),
+
+	on_construct = function(pos)
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
+	end,
+
+	on_place = function(itemstack, placer, pointed_thing)
+		itemstack = default.sapling_on_place(itemstack, placer, pointed_thing,
+			"default:emergent_jungle_sapling",
+			-- minp, maxp to be checked, relative to sapling pos
+			{x = -3, y = -5, z = -3},
+			{x = 3, y = 31, z = 3},
+			-- maximum interval of interior volume check
+			4)
+
+		return itemstack
+	end,
+})
+
 
 minetest.register_node("default:pine_tree", {
 	description = "Pine Tree",