DEL with key list is broken

check_del_key_list.lua

pcall(require, 'luarocks.require')

local sidereal = require 'sidereal' -- sudo luarocks install sidereal --from=http://luarocks.org/repositories/rocks-cvs

--------------------------------------------------------------------------------
-- Some value printing code
--------------------------------------------------------------------------------

require 'lua-nucleo.module' -- sudo luarocks install lua-nucleo
require 'lua-nucleo.strict'

local tstr = import 'lua-nucleo/tstr.lua' { 'tstr' } -- Lua value to string

local N = 1
local P = function(...) print(N .. ":", tstr(assert(...))); N = N + 1 end

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-- Connect to Redis
--------------------------------------------------------------------------------

local R = assert(sidereal.connect("localhost", 6379))
R:flushdb()

--------------------------------------------------------------------------------
-- Fill data
--------------------------------------------------------------------------------

local init = function()
  assert(R:set("ONE", "one"))
  assert(R:set("TWO", "two"))
end

--------------------------------------------------------------------------------
-- This works
--------------------------------------------------------------------------------

init()
P (R:keys("*"))
P (R:del("ONE TWO"))
P (R:keys("*"))
--[[-->
1:	{"TWO","ONE"}
2:	2
3:	{}

redis> monitor
+1287885125.12932 "KEYS" "*"
+1287885125.13170 "DEL" "ONE" "TWO"
+1287885125.13544 "KEYS" "*"
--]]

--------------------------------------------------------------------------------
-- This does not
--------------------------------------------------------------------------------

init()
P (R:keys("*"))
P (R:del({"ONE", "TWO"}))
P (R:keys("*"))
--[[-->
4:	{"TWO","ONE"}
5:	0
6:	{"TWO","ONE"}

redis> monitor
+1287885125.14731 "KEYS" "*"
+1287885125.14932 "DEL" "table:" "0x9c12310"
+1287885125.15094 "KEYS" "*"
--]]