From 4bba371644818d79b5f8481b5b31c53ea8ecbcc5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sergey=20M=E2=80=A4?= <dstftw@gmail.com>
Date: Sun, 4 Oct 2015 20:33:42 +0600
Subject: [PATCH] [YoutubeDL] Autocalculate ext for subtitles when missing

---
 youtube_dl/YoutubeDL.py        | 11 +++++++++--
 youtube_dl/extractor/common.py |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index d65253882..adf70d658 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -1232,13 +1232,20 @@ def process_video_result(self, info_dict, download=True):
             except (ValueError, OverflowError, OSError):
                 pass
 
+        subtitles = info_dict.get('subtitles')
+        if subtitles:
+            for _, subtitle in subtitles.items():
+                for subtitle_format in subtitle:
+                    if 'ext' not in subtitle_format:
+                        subtitle_format['ext'] = determine_ext(subtitle_format['url']).lower()
+
         if self.params.get('listsubtitles', False):
             if 'automatic_captions' in info_dict:
                 self.list_subtitles(info_dict['id'], info_dict.get('automatic_captions'), 'automatic captions')
-            self.list_subtitles(info_dict['id'], info_dict.get('subtitles'), 'subtitles')
+            self.list_subtitles(info_dict['id'], subtitles, 'subtitles')
             return
         info_dict['requested_subtitles'] = self.process_subtitles(
-            info_dict['id'], info_dict.get('subtitles'),
+            info_dict['id'], subtitles,
             info_dict.get('automatic_captions'))
 
         # We now pick which formats have to be downloaded
diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index 4fe2307cd..dbae75406 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -165,6 +165,7 @@ class InfoExtractor(object):
                     with the "ext" entry and one of:
                         * "data": The subtitles file contents
                         * "url": A URL pointing to the subtitles file
+                    "ext" will be calculated from URL if missing
     automatic_captions: Like 'subtitles', used by the YoutubeIE for
                     automatically generated captions
     duration:       Length of the video in seconds, as an integer.