[deviantart] Metadata extractor breaks on certain posts

[kargaroc]

Here's my config.json:

{
 "extractor": {
  "deviantart": {
   "client-id": "<id>",
   "client-secret": "<secret>",
   "metadata": true,
   "postprocessors": [{
    "name": "metadata",
    "mode": "custom",
    "extension": "htm",
    "format": "<b>{title}<br />{date}<br />{category_path}</b><hr>{description}<hr>{url}<br />{tags}"
   }]
  }
 }
}

Try to download the following:
https://www.deviantart.com/aeonrin
with these settings and it will break

see

[gallery-dl][debug] Version 1.10.4
[gallery-dl][debug] Python 3.7.4 - Linux-5.2.9-arch1-1-ARCH-x86_64-with-arch
[gallery-dl][debug] requests 2.22.0 - urllib3 1.25.3
[gallery-dl][debug] Starting DownloadJob for 'https://www.deviantart.com/aeonrin/gallery/?catpath=/'
[gallery-dl][debug] Updating urllib3 ciphers
[deviantart][debug] Using DeviantartGalleryExtractor for 'https://www.deviantart.com/aeonrin/gallery/?catpath=/'
[urllib3.connectionpool][debug] Starting new HTTPS connection (1): www.deviantart.com:443
[urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/user/profile/aeonrin HTTP/1.1" 200 1514
[urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/gallery/all?username=aeonrin&offset=0&limit=24&mature_content=true HTTP/1.1" 200 469
[urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/deviation/metadata?deviationids%5B0%5D=1F1C90EC-C96C-0C32-B9D8-58470C68E2E8&mature_content=true HTTP/1.1" 200 296
[deviantart][debug] Active postprocessor modules: [MetadataPP]
[urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/deviation/content?deviationid=1F1C90EC-C96C-0C32-B9D8-58470C68E2E8 HTTP/1.1" 200 1052
./gallery-dl/deviantart/aeonrin/deviantart_555918906_..htm
[urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/gallery/all?username=aeonrin&offset=24&limit=24&mature_content=true HTTP/1.1" 200 70
[urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/deviation/metadata?mature_content=true HTTP/1.1" 400 124
[deviantart][debug] {"error":"invalid_request","error_description":"Request field validation failed.","error_details":{"deviationids":"deviationids is required"},"status":"error"}
[deviantart][error] API responded with 400 Bad Request
[deviantart][error] An unexpected error occurred: KeyError - 'metadata'. Please run gallery-dl again with the --verbose flag, copy its output and report this issue on https://github.com/mikf/gallery-dl/issues .
[deviantart][debug] 
Traceback (most recent call last):
  File "gallery-dl-master/gallery_dl/job.py", line 47, in run
    for msg in self.extractor:
  File "gallery-dl-master/gallery_dl/extractor/deviantart.py", line 72, in items
    for deviation in self.deviations():
  File "gallery-dl-master/gallery_dl/extractor/deviantart.py", line 986, in _pagination
    self._metadata(data["results"])
  File "gallery-dl-master/gallery_dl/extractor/deviantart.py", line 1003, in _metadata
    deviations, self.deviation_metadata(deviations)):
  File "gallery-dl-master/gallery_dl/extractor/deviantart.py", line 881, in deviation_metadata
    return self._call(endpoint, params)["metadata"]
KeyError: 'metadata'```

[mikf]

Most of this user's deviations are private. Run gallery-dl oauth:deviantart to get a refresh-token so gallery-dl can see and download them. This will also "fix" this issue, but I might as well make sure this can't happen again and also add log message about private deviations.

[github-userx]

Great idea Mike, thanks for always improving gallery-dl so much! You’re the best.