Kelsey Hightower's patch to issue #32 (in github) -- pip crashes when server does not send content-type header

patch_issue_32.patch

# HG changeset patch -- Bitbucket.org
# Project pip
# URL https://bitbucket.org/khightower/pip/overview
# User Kelsey Hightower <kelsey.hightower@gmail.com>
# Date 1296967318 18000
# Node ID 1bb3bf439fdb61596b1f28ad32e7ba60e67ff064
# Parent  0542924d062debf8a4b9a8c83da8241411955139
Fixing issue 207 -- pip crashes when server does not send content-type header

--- a/pip/download.py
+++ b/pip/download.py
@@ -427,7 +427,13 @@ def unpack_http_url(link, location, down
         logger.notify('Using download cache from %s' % target_file)
     else:
         resp = _get_response_from_url(target_url, link)
-        content_type = resp.info()['content-type']
+        if 'content-type' in resp.info():
+            content_type = resp.info()['content-type']
+        else:
+            # The HTTP response header did not define the content-type.
+            # Set content-type to an empty string which supports the
+            # 'lower' attribute required by mimetypes.guess_extension()
+            content_type = ''
         filename = link.filename
         ext = splitext(filename)[1]
         if not ext: