关于lua包nil截断的问题

local unpack = unpack or table.unpack

-- 解决原生pack的nil截断问题，SafePack与SafeUnpack要成对使用
function SafePack(...)
    local params = {...}
    params.n = select('#', ...)
    return params
end

-- 解决原生unpack的nil截断问题，SafePack与SafeUnpack要成对使用
function SafeUnpack(safe_pack_tb)
    return unpack(safe_pack_tb, 1, safe_pack_tb.n)
end

-- 对两个SafePack的表执行连接
function ConcatSafePack(safe_pack_l, safe_pack_r)
    local concat = {}
    for i = 1,safe_pack_l.n do
        concat[i] = safe_pack_l[i]
    end
    for i = 1,safe_pack_r.n do
        concat[safe_pack_l.n + i] = safe_pack_r[i]
    end
    concat.n = safe_pack_l.n + safe_pack_r.n
    return concat
end

-- 闭包绑定
function Bind(self, func, ...)
    assert(self == nil or type(self) == "table")
    assert(func ~= nil and type(func) == "function")
    local params = nil
    if self == nil then
        params = SafePack(...)
    else
        params = SafePack(self, ...)
    end
    return function(...)
        local args = ConcatSafePack(params, SafePack(...))
        func(SafeUnpack(args))
    end
end

-- 回调绑定
-- 重载形式：
-- 1、成员函数、私有函数绑定：BindCallback(obj, callback, ...)
-- 2、闭包绑定：BindCallback(callback, ...)
function BindCallback(...)
    local bindFunc = nil
    local params = SafePack(...)
    assert(params.n >= 1, "BindCallback : error params count!")
    if type(params[1]) == "table" and type(params[2]) == "function" then
        bindFunc = Bind(...)
    elseif type(params[1]) == "function" then
        bindFunc = Bind(nil, ...)
    else
        error("BindCallback : error params list!")
    end
    return bindFunc
end