Make bedrock more robust

mods/bedrock/init.lua

@@ -1,3 +1,5 @@
+local BEDROCK_LAYER = -30912 -- determined as appropriate by experiment
+
 minetest.register_ore({
 	ore_type       = "scatter",
 	ore            = "bedrock:bedrock",
@@ -5,7 +7,7 @@ minetest.register_ore({
 	clust_scarcity = 1 * 1 * 1,
 	clust_num_ores = 5,
 	clust_size     = 2,
-	y_min     = -30912, -- Engine changes can modify this value.
+	y_min     = BEDROCK_LAYER, -- Engine changes can modify this value.
 	y_max     = -30656, -- This ensures the bottom of the world is not even loaded.
 })
 
@@ -23,9 +25,14 @@ minetest.register_ore({
 minetest.register_node("bedrock:bedrock", {
 	description = "Bedrock",
 	tiles = {"bedrock_bedrock.png"},
-	drop = "",
 	groups = {unbreakable = 1, not_in_creative_inventory = 1}, -- For Map Tools' admin pickaxe.
 	sounds = default.node_sound_stone_defaults(),
+	is_ground_content = false,
+	on_blast = function() end,
+	on_destruct = function () end,
+	can_dig = function() return false end,
+	diggable = false,
+	drop = "",
 })
 
 minetest.register_node("bedrock:deepstone", {
@@ -36,6 +43,30 @@ minetest.register_node("bedrock:deepstone", {
 	sounds = default.node_sound_stone_defaults(),
 })
 
+-- Generate a perfect bedrock layer at the world bottom
+minetest.register_on_generated(function(minp, maxp)
+	if maxp.y >= BEDROCK_LAYER and minp.y <= BEDROCK_LAYER then
+		local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
+		local data = vm:get_data()
+		local area = VoxelArea:new({MinEdge=emin, MaxEdge=emax})
+		local c_bedrock = minetest.get_content_id("bedrock:bedrock")
+
+		for x = minp.x, maxp.x do
+			for z = minp.z, maxp.z do
+				local p_pos = area:index(x, BEDROCK_LAYER, z)
+				data[p_pos] = c_bedrock
+			end
+		end
+
+		vm:set_data(data)
+		vm:calc_lighting()
+		vm:update_liquids()
+		vm:write_to_map()
+	end
+end)
+
 if minetest.setting_getbool("log_mods") then
 	minetest.log("action", "[bedrock] loaded.")
 end
+
+