Merge pull request #1846 from acdha/paranoid-get_netrc_auth

get_netrc_auth should handle os.path.expanduser failing

diff --combined requests/utils.py
index e69e9a8,04e5a2b..7a4d44d
--- 1/requests/utils.py
--- 2/requests/utils.py
+++ b/requests/utils.py
@@@ -64,22 -64,31 +64,31 @@@ def super_len(o)
          # e.g. BytesIO, cStringIO.StringI
          return len(o.getvalue())
  
+ 
  def get_netrc_auth(url):
      """Returns the Requests tuple auth for a given url from netrc."""
  
      try:
          from netrc import netrc, NetrcParseError
  
-         locations = (os.path.expanduser('~/{0}'.format(f)) for f in NETRC_FILES)
          netrc_path = None
  
-         for loc in locations:
-             if os.path.exists(loc) and not netrc_path:
+         for f in NETRC_FILES:
+             try:
+                 loc = os.path.expanduser('~/{0}'.format(f))
+             except KeyError:
+                 # os.path.expanduser can fail when $HOME is undefined and
+                 # getpwuid fails. See http://bugs.python.org/issue20164 &
+                 # https://github.com/kennethreitz/requests/issues/1846
+                 return
+ 
+             if os.path.exists(loc):
                  netrc_path = loc
+                 break
  
          # Abort early if there isn't one.
          if netrc_path is None:
-             return netrc_path
+             return
  
          ri = urlparse(url)
  
@@@ -487,16 -496,7 +496,16 @@@ def get_environ_proxies(url)
  
      # If the system proxy settings indicate that this URL should be bypassed,
      # don't proxy.
 -    if proxy_bypass(netloc):
 +    # The proxy_bypass function is incredibly buggy on OS X in early versions
 +    # of Python 2.6, so allow this call to fail. Only catch the specific
 +    # exceptions we've seen, though: this call failing in other ways can reveal
 +    # legitimate problems.
 +    try:
 +        bypass = proxy_bypass(netloc)
 +    except (TypeError, socket.gaierror):
 +        bypass = False
 +
 +    if bypass:
          return {}
  
      # If we get here, we either didn't have no_proxy set or we're not going