[youtube] Match more truncated URLs (Closes #2402)

test/test_all_urls.py

@@ -68,6 +68,9 @@ class TestAllURLsMatching(unittest.TestCase):
     def test_youtube_show_matching(self):
         self.assertMatch('http://www.youtube.com/show/airdisasters', ['youtube:show'])
 
+    def test_youtube_truncated(self):
+        self.assertMatch('http://www.youtube.com/watch?', ['youtube:truncated_url'])
+
     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

@@ -1815,7 +1815,7 @@ class YoutubeTruncatedURLIE(InfoExtractor):
     IE_NAME = 'youtube:truncated_url'
     IE_DESC = False  # Do not list
     _VALID_URL = r'''(?x)
-        (?:https?://)?[^/]+/watch\?feature=[a-z_]+$|
+        (?:https?://)?[^/]+/watch\?(?:feature=[a-z_]+)?$|
         (?:https?://)?(?:www\.)?youtube\.com/attribution_link\?a=[^&]+$
     '''