[youtube] Fix some issues with the detection of playlist/channel urls (reported in #1374)

They were being caught by YoutubeUserIE, now it only extracts a url if the rest of extractors aren't suitable.
Now the url tests check that the urls can only be extracted with an specific extractor.

test/test_all_urls.py

@@ -21,14 +21,15 @@ class TestAllURLsMatching(unittest.TestCase):
         self.assertEqual(self.matching_ies(url), ie_list)
 
     def test_youtube_playlist_matching(self):
-        self.assertTrue(YoutubePlaylistIE.suitable(u'ECUl4u3cNGP61MdtwGTqZA0MreSaDybji8'))
-        self.assertTrue(YoutubePlaylistIE.suitable(u'UUBABnxM4Ar9ten8Mdjj1j0Q')) #585
-        self.assertTrue(YoutubePlaylistIE.suitable(u'PL63F0C78739B09958'))
-        self.assertTrue(YoutubePlaylistIE.suitable(u'https://www.youtube.com/playlist?list=UUBABnxM4Ar9ten8Mdjj1j0Q'))
-        self.assertTrue(YoutubePlaylistIE.suitable(u'https://www.youtube.com/course?list=ECUl4u3cNGP61MdtwGTqZA0MreSaDybji8'))
-        self.assertTrue(YoutubePlaylistIE.suitable(u'https://www.youtube.com/playlist?list=PLwP_SiAcdui0KVebT0mU9Apz359a4ubsC'))
-        self.assertTrue(YoutubePlaylistIE.suitable(u'https://www.youtube.com/watch?v=AV6J6_AeFEQ&playnext=1&list=PL4023E734DA416012')) #668
-        self.assertFalse(YoutubePlaylistIE.suitable(u'PLtS2H6bU1M'))
+        assertPlaylist = lambda url: self.assertMatch(url, ['youtube:playlist'])
+        assertPlaylist(u'ECUl4u3cNGP61MdtwGTqZA0MreSaDybji8')
+        assertPlaylist(u'UUBABnxM4Ar9ten8Mdjj1j0Q') #585
+        assertPlaylist(u'PL63F0C78739B09958')
+        assertPlaylist(u'https://www.youtube.com/playlist?list=UUBABnxM4Ar9ten8Mdjj1j0Q')
+        assertPlaylist(u'https://www.youtube.com/course?list=ECUl4u3cNGP61MdtwGTqZA0MreSaDybji8')
+        assertPlaylist(u'https://www.youtube.com/playlist?list=PLwP_SiAcdui0KVebT0mU9Apz359a4ubsC')
+        assertPlaylist(u'https://www.youtube.com/watch?v=AV6J6_AeFEQ&playnext=1&list=PL4023E734DA416012') #668
+        self.assertFalse('youtube:playlist' in self.matching_ies(u'PLtS2H6bU1M'))
 
     def test_youtube_matching(self):
         self.assertTrue(YoutubeIE.suitable(u'PLtS2H6bU1M'))
@@ -37,9 +38,10 @@ class TestAllURLsMatching(unittest.TestCase):
         self.assertMatch('http://www.youtube.com/v/BaW_jenozKc', ['youtube'])
 
     def test_youtube_channel_matching(self):
-        self.assertTrue(YoutubeChannelIE.suitable('https://www.youtube.com/channel/HCtnHdj3df7iM'))
-        self.assertTrue(YoutubeChannelIE.suitable('https://www.youtube.com/channel/HCtnHdj3df7iM?feature=gb_ch_rec'))
-        self.assertTrue(YoutubeChannelIE.suitable('https://www.youtube.com/channel/HCtnHdj3df7iM/videos'))
+        assertChannel = lambda url: self.assertMatch(url, ['youtube:channel'])
+        assertChannel('https://www.youtube.com/channel/HCtnHdj3df7iM')
+        assertChannel('https://www.youtube.com/channel/HCtnHdj3df7iM?feature=gb_ch_rec')
+        assertChannel('https://www.youtube.com/channel/HCtnHdj3df7iM/videos')
 
     def test_youtube_user_matching(self):
         self.assertMatch('www.youtube.com/NASAgovVideo/videos', ['youtube:user'])
@@ -50,6 +52,9 @@ class TestAllURLsMatching(unittest.TestCase):
         self.assertMatch('https://www.youtube.com/feed/recommended', ['youtube:recommended'])
         self.assertMatch('https://www.youtube.com/my_favorites', ['youtube:favorites'])
 
+    def test_youtube_show_matching(self):
+        self.assertMatch('http://www.youtube.com/show/airdisasters', ['youtube:show'])
+
     def test_justin_tv_channelid_matching(self):
         self.assertTrue(JustinTVIE.suitable(u"justin.tv/vanillatv"))
         self.assertTrue(JustinTVIE.suitable(u"twitch.tv/vanillatv"))

youtube_dl/extractor/youtube.py

@@ -386,7 +386,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
     @classmethod
     def suitable(cls, url):
         """Receives a URL and returns True if suitable for this IE."""
-        if YoutubePlaylistIE.suitable(url) or YoutubeSubscriptionsIE.suitable(url): return False
+        if YoutubePlaylistIE.suitable(url): return False
         return re.match(cls._VALID_URL, url, re.VERBOSE) is not None
 
     def report_video_webpage_download(self, video_id):
@@ -1021,8 +1021,12 @@ class YoutubeUserIE(InfoExtractor):
     _GDATA_URL = 'http://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d&alt=json'
     IE_NAME = u'youtube:user'
 
+    @classmethod
     def suitable(cls, url):
-        if YoutubeIE.suitable(url) or YoutubeFavouritesIE.suitable(url): return False
+        # Don't return True if the url can be extracted with other youtube
+        # extractor, the regex would is too permissive and it would match.
+        other_ies = iter(klass for (name, klass) in globals().items() if name.endswith('IE') and klass is not cls)
+        if any(ie.suitable(url) for ie in other_ies): return False
         else: return super(YoutubeUserIE, cls).suitable(url)
 
     def _real_extract(self, url):