Not correctly used LRANGE in redis persistence

[mocheng]

In https://github.com/mcollina/mosca/blob/master/lib/persistence/redis.js line 319, it is

RedisPersistence.prototype.streamOfflinePackets = function(client, cb) {
  var that = this;

  if (this._cleanClient(client)) {
    return;
  }

  that._client.lrange("packets:" + client.id, -1, 10000, function(err, results) {
  }

It looks the usage of LRANGE is not correct.

According to http://redis.io/commands/lrange , the command "LRANGE packets:client_id -1 1000" would only get last element in "packets:client_id". As a result, streamOfflinePackets only send out one offline packet. I suppose this is not correct.

Please correct me if I'm wrong.

[mcollina]

You are right! It should be LRANGE packets:client_id 0 1000.
Can you please submit a pull request with a unit test?