Fix AssertionError when og property not found

[youtube-dl] / youtube_dl / extractor / common.py

diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index ce349fe207af21690c95b86dd7a293220ac7025e..fb2d50a098992f8088c41259b73d653c6f6f173d 100644 (file)
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -63,7 +63,7 @@ class InfoExtractor(object):
                     * ext       Will be calculated from url if missing
                     * format    A human-readable description of the format
                                 ("mp4 container with h264/opus").
-                                Calculated from the format_id, width, height 
+                                Calculated from the format_id, width, height.
                                 and format_note fields if missing.
                     * format_id A short description of the format
                                 ("mp4_h264_opus" or "19")
@@ -71,6 +71,9 @@ class InfoExtractor(object):
                                 ("3D" or "DASH video")
                     * width     Width of the video, if known
                     * height    Height of the video, if known
+    webpage_url:    The url to the video webpage, if given to youtube-dl it
+                    should allow to get the same result again. (It will be set
+                    by YoutubeDL if it's missing)
 
     Unless mentioned otherwise, the fields should be Unicode strings.
 
@@ -319,7 +322,9 @@ class InfoExtractor(object):
         if name is None:
             name = 'OpenGraph %s' % prop
         escaped = self._search_regex(self._og_regex(prop), html, name, flags=re.DOTALL, **kargs)
-        return unescapeHTML(escaped)
+        if not escaped is None:
+            return unescapeHTML(escaped)
+        return None
 
     def _og_search_thumbnail(self, html, **kargs):
         return self._og_search_property('image', html, u'thumbnail url', fatal=False, **kargs)