Use If-Range instead of If-Match/If-Unmodified-Since for partial requests.

net/tools/testserver/testserver.py

 #!/usr/bin/env python
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """This is a simple HTTP/FTP/TCP/UDP/BASIC_AUTH_PROXY/WEBSOCKET server used for
 testing Chrome.
 
 It supports several test URLs, as specified by the handlers in TestPageHandler.
 By default, it listens on an ephemeral port and sends the port number back to
@@ skipping 1611 matching lines @@
     if fail_precondition != 0:
       TestPageHandler.fail_precondition[token] -= 1
 
     first_byte = 0
     last_byte = size - 1
 
     # Does that define what we want to return, or do we need to apply
     # a range?
     range_response = False
     range_header = self.headers.getheader('range')
+
+    if fail_precondition and self.headers.getheader('If-Range'):
+      # Failing a precondition for an If-Range just means that we are going to
+      # return the entire entity ignoring the Range header.
+      respond_to_range = False
+
     if range_header and respond_to_range:
       mo = re.match("bytes=(\d*)-(\d*)", range_header)
       if mo.group(1):
         first_byte = int(mo.group(1))
       if mo.group(2):
         last_byte = int(mo.group(2))
       if last_byte > size - 1:
         last_byte = size - 1
       range_response = True
       if last_byte < first_byte:
         return False
 
-    if (fail_precondition and
-        (self.headers.getheader('If-Modified-Since') or
-         self.headers.getheader('If-Match'))):
-      self.send_response(412)
-      self.end_headers()
-      return True
-
     if range_response:
       self.send_response(206)
       self.send_header('Content-Range',
                        'bytes %d-%d/%d' % (first_byte, last_byte, size))
     else:
       self.send_response(200)
     self.send_header('Content-Type', 'application/octet-stream')
     self.send_header('Content-Length', last_byte - first_byte + 1)
     if send_verifiers:
       # If fail_precondition is non-zero, then the ETag for each request will be
@@ skipping 649 matching lines @@
                                   'an anonymous user.')
     self.option_parser.add_option('--disable-channel-id', action='store_true')
     self.option_parser.add_option('--disable-extended-master-secret',
                                   action='store_true')
     self.option_parser.add_option('--token-binding-params', action='append',
                                   default=[], type='int')
 
 
 if __name__ == '__main__':
   sys.exit(ServerRunner().main())