[YoutubeDL] Disable newline conversion when writing subtitles

By default io.open() convert all '\n' occurrences to '\r\n' when writing
files. If the content already contains '\r\n', it will be converted to
'\r\r\n', breaking some video players.

diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index fd7577bb8032c40bd1f1a668ae4651d9fae946ef..e844dc98a5b3915070ffae079395233de7ed04f7 100755 (executable)
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -1603,6 +1603,8 @@ class YoutubeDL(object):
                         self.to_screen('[info] Video subtitle %s.%s is already_present' % (sub_lang, sub_format))
                     else:
                         self.to_screen('[info] Writing video subtitles to: ' + sub_filename)
+                        # Use newline='' to prevent conversion of newline characters
+                        # See https://github.com/rg3/youtube-dl/issues/10268
                         with io.open(encodeFilename(sub_filename), 'w', encoding='utf-8', newline='') as subfile:
                             subfile.write(sub_data)
                 except (OSError, IOError):