ServerNotFoundError when using proxy and no default gateway is configured

Windows 7 x64, Python 2.7.6 x86_64, httplib2 0.8

If no default gateway is configured, using httplib2 via a proxy will fail with 
ServerNotFoundError. With any gateway configured (no matter whether it actually 
works or not), it will succeed. I guess that getaddrinfo is used to resolve the 
hostname. Depending on how it is called, it will return an error if there is no 
route to the host. Unfortunately I don't know any details about getaddrinfo, 
how to call it correctly and whether it is actually called by httplib2.
A workaround is to use proxy_rdns=True.

I used this script based on the one from the examples page:

import httplib2
import socks

httplib2.debuglevel=4
h = httplib2.Http(proxy_info = httplib2.ProxyInfo(socks.PROXY_TYPE_HTTP, 
'192.168.1.123', 3128))
r,c = h.request("http://example.com")

I first ran it without a default gateway. Then I set the default gateway to a 
valid LAN IP that is unused and ran it again. This is the output:

C:\Users\someuser\Desktop>python foo.py
Traceback (most recent call last):
  File "foo.py", line 6, in <module>
    r,c = h.request("http://example.com")
  File "C:\Python27\lib\site-packages\httplib2\__init__.py", line 1570, in request
    (response, content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey
)
  File "C:\Python27\lib\site-packages\httplib2\__init__.py", line 1317, in _request
    (response, content) = self._conn_request(conn, request_uri, method, body, headers)
  File "C:\Python27\lib\site-packages\httplib2\__init__.py", line 1258, in _conn_request
    raise ServerNotFoundError("Unable to find the server at %s" % conn.host)
httplib2.ServerNotFoundError: Unable to find the server at example.com

C:\Users\someuser\Desktop>route add 0.0.0.0 mask 0.0.0.0 192.168.1.xxx  # 
(where xxx is unused, i.e. not a working gateway)
 OK!

C:\Users\someuser\Desktop>python foo.py
connect: (example.com, 80) ************
proxy: ('192.168.1.123', 3128, None, None, None) ************
send: 'GET / HTTP/1.1\r\nHost: example.com\r\naccept-encoding: gzip, 
deflate\r\nuser-agent: Python-httplib2/0.8 (gzip)\r
\n\r\n'
reply: 'HTTP/1.1 200 OK\r\n'
header: Accept-Ranges: bytes
header: Cache-Control: max-age=604800
header: Content-Type: text/html
header: Date: Fri, 10 Jan 2014 14:45:40 GMT
header: Etag: "359670651"
header: Expires: Fri, 17 Jan 2014 14:45:40 GMT
header: Last-Modified: Fri, 09 Aug 2013 23:54:35 GMT
header: Server: ECS (iad/1984)
header: X-Cache: HIT
header: x-ec-custom-error: 1
header: Content-Length: 1270

C:\Users\someuser\Desktop>
Original issue reported on code.google.com by Foobarte...@gmail.com on 10 Jan 2014 at 3:14
dxlove / httplib2

ServerNotFoundError when using proxy and no default gateway is configured #303
