Use JSON in xban.db

init.lua

@@ -346,7 +346,7 @@ local function save_db()
 	local f, e = io.open(DB_FILENAME, "wt")
 	db.timestamp = os.time()
 	if f then
-		local ok, err = f:write(xban.serialize(db))
+		local ok, err = f:write(assert(xban.serialize_db(db)))
 		if not ok then
 			WARNING("Unable to save database: %s", err)
 		end
@@ -368,7 +368,7 @@ local function load_db()
 		WARNING("Unable to load database: %s", "Read failed")
 		return
 	end
-	local t, e2 = minetest.deserialize(cont)
+	local t, e2 = xban.deserialize_db(cont)
 	if not t then
 		WARNING("Unable to load database: %s",
 		  "Deserialization failed: "..(e2 or "unknown error"))

serialize.lua

@@ -27,5 +27,45 @@ local function my_serialize_2(t, level)
 end
 
 function xban.serialize(t)
+	minetest.log("warning", "[xban2] xban.serialize() is deprecated")
 	return "return {\n"..my_serialize_2(t, 1).."\n}"
 end
+
+-- JSON doesn't allow combined string+number keys, this function moves any
+-- number keys into an "entries" table
+function xban.serialize_db(t)
+	local res = {}
+	local entries = {}
+	for k, v in pairs(t) do
+		if type(k) == "number" then
+			entries[k] = v
+		else
+			res[k] = v
+		end
+	end
+	res.entries = entries
+	return minetest.write_json(res, true)
+end
+
+function xban.deserialize_db(s)
+	if s:sub(1, 1) ~= "{" then
+		-- Load legacy databases
+		return minetest.deserialize(s)
+	end
+
+	local res, err = minetest.parse_json(s)
+	if not res then
+		return nil, err
+	end
+
+	-- Remove all "null"s added by empty tables
+	for i, entry in ipairs(res.entries or {}) do
+		entry.names = entry.names or {}
+		entry.record = entry.record or {}
+		res[i] = entry
+	end
+	res.entries = nil
+
+	return res
+end
+