X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=youtube_dl%2Fextractor%2Ffrontendmasters.py;h=cb57ba007fd61683630ea6cf2dd2d4d15d01ecc4;hb=3052a30d4259b182904e5d2430077039461745bb;hp=770db46d0d63a0bdebea2d362850155b55044d93;hpb=4ecf300d13a6503ae80b76e01047b41d86ab4d92;p=youtube-dl

diff --git a/youtube_dl/extractor/frontendmasters.py b/youtube_dl/extractor/frontendmasters.py
index 770db46d0..cb57ba007 100644
--- a/youtube_dl/extractor/frontendmasters.py
+++ b/youtube_dl/extractor/frontendmasters.py
@@ -11,6 +11,7 @@ from ..compat import (
 from ..utils import (
     ExtractorError,
     parse_duration,
+    url_or_none,
     urlencode_postdata,
 )
 
@@ -80,7 +81,7 @@ class FrontendMastersPageBaseIE(FrontendMastersBaseIE):
         chapters = []
         lesson_elements = course.get('lessonElements')
         if isinstance(lesson_elements, list):
-            chapters = [e for e in lesson_elements if isinstance(e, compat_str)]
+            chapters = [url_or_none(e) for e in lesson_elements if url_or_none(e)]
         return chapters
 
     @staticmethod