Dropbox Core API 0 bytes size in metadata for image

问题

I'm using Dropox Core API for my App. I retrieve all the metadata with the good endpoint. But sometimes I got metadata like this :

   "size": "0 bytes",
    "rev": "38af1b183490",
    "thumb_exists": true,
    "bytes": 2453963,
    "modified": "Mon, 07 Apr 2014 23:13:16 +0000",
    "client_mtime": "Thu, 29 Aug 2013 01:12:02 +0000",
    "path": "/Photos/flower.jpg",
    "photo_info": {
      "lat_long": [
        37.77256666666666,
        -122.45934166666667
      ],
      "time_taken": "Wed, 28 Aug 2013 18:12:02 +0000"
    },
    "is_dir": false,
    "icon": "page_white_picture",
    "root": "dropbox",
    "mime_type": "image/jpeg",
    "revision": 14511

The problem is "size": "0 bytes". The thumbnail exits and the image too, but this data mess up my app, because I check the size before download the file, to avoid to download too big files. I could avoid to download pictures with size equal to zero but it is just a way to get around the problem while images are valids.

Is there any reasons to get a 0 bytes size ? What does it mean ?

来源：https://stackoverflow.com/questions/24059681/dropbox-core-api-0-bytes-size-in-metadata-for-image