dropbox extractor returns invalid url and extension

[JBuzzard]

Two problems:

1. The 'url' of the video is incorrect. It uses an '&' for the query string when it should be a '?'
   "url":"https://www.dropbox.com/s/6mlss7reiiabqjn/TestVideoMkv1.mkv&dl=1",

2. The extension\type is undetermined when it should be .MKV. This could probably be parsed from the url fairly easily.
   "ext":"unknown_video"

youtube-dl.exe -i --default-search "xx:" --no-warnings --no-playlist --max-downloads 1 --skip-download -j https://www.dropbox.com/s/6mlss7reiiabqjn/TestVideoMkv1.mkv

{
"display_id":"6mlss7reiiabqjn",
"extractor":"Dropbox",
"format":"0 - unknown",
"format_id":"0",
"id":"6mlss7reiiabqjn",
"stitle":"TestVideoMkv1",
"playlist":null,
"title":"TestVideoMkv1",
"url":"https://www.dropbox.com/s/6mlss7reiiabqjn/TestVideoMkv1.mkv&dl=1",
"extractor_key":"Dropbox",
"playlist_index":null,
"ext":"unknown_video",
"webpage_url":"https://www.dropbox.com/s/6mlss7reiiabqjn/TestVideoMkv1.mkv",
"_filename":"TestVideoMkv1-6mlss7reiiabqjn.unknown_video",
"fulltitle":"TestVideoMkv1",
"webpage_url_basename":"TestVideoMkv1.mkv"
}

[jaimeMF]

Thanks for the report!, It will be fixed in the next version.

The problem with the extension was a consequence of the first issue, we already detect the extension from the url (but the &dl=1 made it fail).

[phihag]

Fixed in youtube-dl 2014.10.05. Type youtube-dl -U to update.