[utils] import re

[youtube-dl] / youtube_dl / downloader / http.py

diff --git a/youtube_dl/downloader/http.py b/youtube_dl/downloader/http.py
index b7f144af9ea33a102246632e04e71707be3d98ad..f796ee1135da582b717771681deccd5b3aa29f38 100644 (file)
--- a/youtube_dl/downloader/http.py
+++ b/youtube_dl/downloader/http.py
@@ -4,6 +4,7 @@ import errno
 import os
 import socket
 import time
+import re
 
 from .common import FileDownloader
 from ..compat import (
@@ -57,6 +58,20 @@ class HttpFD(FileDownloader):
             # Establish connection
             try:
                 data = self.ydl.urlopen(request)
+
+                if resume_len > 0:
+                    content_range = data.headers.get('Content-Range')
+                    if content_range:
+                        content_range_m = re.search(r'bytes (\d+)-', content_range)
+                        if content_range_m:
+                            # Content-Range is correct - go on
+                            if resume_len == int(content_range_m.group(1)):
+                                break
+
+                    # Content-Range is invalid - wipe the file and do entire redownload
+                    resume_len = 0
+                    open_mode = 'wb'
+
                 break
             except (compat_urllib_error.HTTPError, ) as err:
                 if (err.code < 500 or err.code >= 600) and err.code != 416: