1 files changed, 24 insertions, 0 deletions
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index efbe64fb3..079e8d2c3 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -205,6 +205,10 @@ def get_element_by_attribute(attribute, value, html):
 
 def clean_html(html):
     """Clean an HTML snippet into a readable string"""
+
+    if html is None:  # Convenience for sanitizing descriptions etc.
+        return html
+
     # Newline vs <br />
     html = html.replace('\n', ' ')
     html = re.sub(r'\s*<\s*br\s*/?\s*>\s*', '\n', html)
@@ -1550,3 +1554,23 @@ def ytdl_is_updateable():
 def args_to_str(args):
     # Get a short string representation for a subprocess command
     return ' '.join(shlex_quote(a) for a in args)
+
+
+def urlhandle_detect_ext(url_handle):
+    try:
+        url_handle.headers
+        getheader = lambda h: url_handle.headers[h]
+    except AttributeError:  # Python < 3
+        getheader = url_handle.info().getheader
+
+    return getheader('Content-Type').split("/")[1]
+
+
+def age_restricted(content_limit, age_limit):
+    """ Returns True iff the content should be blocked """
+
+    if age_limit is None:  # No limit set
+        return False
+    if content_limit is None:
+        return False  # Content available for everyone
+    return age_limit < content_limit