Repository: youtube-dl
Issue: Feature request: Have youtube-dl  teat search-result page (on C-Span.org) as a playlist
Labels: request

---
- [X] I've **verified** and **I assure** that I'm running youtube-dl **2017.04.11**

### Before submitting an *issue* make sure you have:
- [X] At least skimmed through [README](https://github.com/rg3/youtube-dl/blob/master/README.md) and **most notably** [FAQ](https://github.com/rg3/youtube-dl#faq) and [BUGS](https://github.com/rg3/youtube-dl#bugs) sections
- [X] [Searched](https://github.com/rg3/youtube-dl/search?type=Issues) the bugtracker for similar issues including closed ones

### What is the purpose of your *issue*?
- [X] Feature request (request for a new functionality)
---
```
youtube-dl -v https://www.c-span.org/search/?searchtype=Videos&sort=Newest&seriesid[]=37
[1] 5661
[2] 5662
bash: seriesid[]: bad array subscript
me@laptop ~/Videos/youtube-dl/kagan $ [debug] System config: [u'-o', u'~/Videos/youtube-dl/%(title)s_%(id)s.%(ext)s', u'--netrc', u'--restrict-filenames', u'--write-description', u'--write-sub', u'--yes-playlist', u'--ignore-errors']
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'https://www.c-span.org/search/?searchtype=Videos']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2017.04.11
[debug] Python version 2.7.12 - Linux-4.4.0-71-generic-x86_64-with-LinuxMint-18.1-serena
[debug] exe versions: ffmpeg 2.8.11-0ubuntu0.16.04.1, ffprobe 2.8.11-0ubuntu0.16.04.1
[debug] Proxy map: {}
[generic] ?searchtype=Videos: Requesting header
WARNING: Falling back on generic information extractor.
[generic] ?searchtype=Videos: Downloading webpage
[generic] ?searchtype=Videos: Extracting information
ERROR: Unsupported URL: https://www.c-span.org/search/?searchtype=Videos
Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/generic.py", line 1835, in _real_extract
    doc = compat_etree_fromstring(webpage.encode('utf-8'))
  File "/usr/local/bin/youtube-dl/youtube_dl/compat.py", line 2526, in compat_etree_fromstring
    doc = _XML(text, parser=etree.XMLParser(target=_TreeBuilder(element_factory=_element_factory)))
  File "/usr/local/bin/youtube-dl/youtube_dl/compat.py", line 2515, in _XML
    parser.feed(text)
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 1653, in feed
    self._raiseerror(v)
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 1517, in _raiseerror
    raise err
ParseError: mismatched tag: line 49, column 116
Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 761, in extract_info
    ie_result = ie.extract(url)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 429, in extract
    ie_result = self._real_extract(url)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/generic.py", line 2698, in _real_extract
    raise UnsupportedError(url)
UnsupportedError: Unsupported URL: https://www.c-span.org/search/?searchtype=Videos
```

### Description of your *issue*, suggested solution and other information
I would wish that supplying a search-result page would lead youtube-dl  to treat the list of "found' videos as a playlist.