From 975d35dbab002fbe65172a4a764b6d10787f9eb6 Mon Sep 17 00:00:00 2001
From: Philipp Hagemeister <phihag@phihag.de>
Date: Thu, 23 Jan 2014 16:14:54 +0100
Subject: [PATCH] [youtube:truncated_url] Also match mail subscription links
 (#2214)

---
 youtube_dl/extractor/youtube.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 175763309..6deb56447 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -1805,7 +1805,10 @@ def _real_extract(self, url):
 class YoutubeTruncatedURLIE(InfoExtractor):
     IE_NAME = 'youtube:truncated_url'
     IE_DESC = False  # Do not list
-    _VALID_URL = r'(?:https?://)?[^/]+/watch\?feature=[a-z_]+$'
+    _VALID_URL = r'''(?x)
+        (?:https?://)?[^/]+/watch\?feature=[a-z_]+$|
+        (?:https?://)?(?:www\.)?youtube\.com/attribution_link\?a=[^&]+$
+    '''
 
     def _real_extract(self, url):
         raise ExtractorError(