-- Variables ending with these names will not

-- have their values printed ('password' includes

-- 'new_password', etc.)

local censored_names = {

	password = true;

	passwd = true;

	pass = true;

	pwd = true;

};

local function get_locals_table(level)

	level = level + 1; -- Skip this function itself

	local locals = {};

	for local_num = 1, math.huge do

		local name, value = debug.getlocal(level, local_num);

		if not name then break; end

		table.insert(locals, { name = name, value = value });

	end

	return locals;

end

local function get_upvalues_table(func)

	local upvalues = {};

	if func then

		for upvalue_num = 1, math.huge do

			local name, value = debug.getupvalue(func, upvalue_num);

			if not name then break; end

			table.insert(upvalues, { name = name, value = value });

		end

	end

	return upvalues;

end

local function string_from_var_table(var_table, max_line_len, indent_str)

	local var_string = {};

	local col_pos = 0;

	max_line_len = max_line_len or math.huge;

	indent_str = "\n"..(indent_str or "");

	for _, var in ipairs(var_table) do

		local name, value = var.name, var.value;

		if name:sub(1,1) ~= "(" then

			if type(value) == "string" then

				if censored_names[name:match("%a+$")] then

					value = "<hidden>";

				else

					value = ("%q"):format(value);

				end

			else

				value = tostring(value);

			end

			if #value > max_line_len then

				value = value:sub(1, max_line_len-3).."…";

			end

			local str = ("%s = %s"):format(name, tostring(value));

			col_pos = col_pos + #str;

			if col_pos > max_line_len then

				table.insert(var_string, indent_str);

				col_pos = 0;

			end

			table.insert(var_string, str);

		end

	end

	if #var_string == 0 then

		return nil;

	else

		return "{ "..table.concat(var_string, ", "):gsub(indent_str..", ", indent_str).." }";

	end

end

function get_traceback_table(thread, start_level)

	local levels = {};

	for level = start_level, math.huge do

		local info;

		if thread then

			info = debug.getinfo(thread, level);

		else

			info = debug.getinfo(level);

		end

		if not info then break; end

		levels[(level-start_level)+1] = {

			level = level;

			info = info;

			locals = get_locals_table(level);

			upvalues = get_upvalues_table(info.func);

		};

	end	

	return levels;

end

function debug.traceback(thread, message, level)

	if type(thread) ~= "thread" then

		thread, message, level = coroutine.running(), thread, message;

	end

	if level and type(message) ~= "string" then

		return nil, "invalid message";

	elseif not level then

	end

	message = message and (message.."\n") or "";

	local levels = get_traceback_table(thread, level+2);

	local lines = {};

	for nlevel, level in ipairs(levels) do

		local info = level.info;

		local line = "...";

		local func_type = info.namewhat.." ";

		if func_type == " " then func_type = ""; end;

		if info.short_src == "[C]" then

			line = "[ C ] "..func_type.."C function "..(info.name and ("%q"):format(info.name) or "(unknown name)")

		elseif info.what == "main" then

			line = "[Lua] "..info.short_src.." line "..info.currentline;

		else

			local name = info.name or " ";

			if name ~= " " then

				name = ("%q"):format(name);

			end

			if func_type == "global " or func_type == "local " then

				func_type = func_type.."function ";

			end

			line = "[Lua] "..info.short_src.." line "..info.currentline.." in "..func_type..name.." defined on line "..info.linedefined;

		end

		nlevel = nlevel-1;

		table.insert(lines, "\t"..(nlevel==0 and ">" or " ").."("..nlevel..") "..line);

		local npadding = (" "):rep(#tostring(nlevel));

		local locals_str = string_from_var_table(level.locals, 65, "\t            "..npadding);

		if locals_str then

			table.insert(lines, "\t    "..npadding.."Locals: "..locals_str);

		end

		local upvalues_str = string_from_var_table(level.upvalues, 65, "\t            "..npadding);

		if upvalues_str then

			table.insert(lines, "\t    "..npadding.."Upvals: "..upvalues_str);

		end

	end

	return message.."stack traceback:\n"..table.concat(lines, "\n");

end