Ignore BOM in batch files (Fixes #2450)

youtube_dl/utils.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+import contextlib
 import ctypes
 import datetime
 import email.utils
@@ -1245,3 +1246,19 @@ except TypeError:
 else:
     struct_pack = struct.pack
     struct_unpack = struct.unpack
+
+
+def read_batch_urls(batch_fd):
+    def fixup(url):
+        if not isinstance(url, compat_str):
+            url = url.decode('utf-8', 'replace')
+        BOM_UTF8 = u'\xef\xbb\xbf'
+        if url.startswith(BOM_UTF8):
+            url = url[len(BOM_UTF8):]
+        url = url.strip()
+        if url.startswith(('#', ';', ']')):
+            return False
+        return url
+
+    with contextlib.closing(batch_fd) as fd:
+        return [url for url in map(fixup, fd) if url]