Use HTTPHeaderDict for response headers.

requests/adapters.py

@@ -31,7 +31,7 @@ from .compat import urlparse, basestring
 from .utils import (DEFAULT_CA_BUNDLE_PATH, get_encoding_from_headers,
                     prepend_scheme_if_needed, get_auth_from_url, urldefragauth,
                     select_proxy)
-from .structures import CaseInsensitiveDict
+from .structures import HTTPHeaderDict
 from .cookies import extract_cookies_to_jar
 from .exceptions import (ConnectionError, ConnectTimeout, ReadTimeout, SSLError,
                          ProxyError, RetryError, InvalidScheme)
@@ -274,7 +274,7 @@ class HTTPAdapter(BaseAdapter):
         response.status_code = getattr(resp, 'status', None)
 
         # Make headers case-insensitive.
-        response.headers = CaseInsensitiveDict(getattr(resp, 'headers', {}))
+        response.headers = HTTPHeaderDict(getattr(resp, 'headers', {}))
 
         # Set encoding.
         response.encoding = get_encoding_from_headers(response.headers)

tests/test_requests.py

@@ -2186,6 +2186,12 @@ class TestRequests:
         fruits = resp.headers['fruit']
         assert fruits == 'Apple, Blood Orange, Banana, Berry, Blue'
 
+        # As we are using HTTPHeaderDict, we should be able to extract the
+        # individual header values too.
+        assert resp.headers.multiget('fruit') == (
+            'Apple', 'Blood Orange', 'Banana', 'Berry, Blue'
+        )
+
     def test_multiple_response_headers_with_same_name_diff_case(self, httpbin):
         # urllib3 seems to have trouble guaranteeing the order of the items when
         # the case is different, so we just need to make sure all of the items
@@ -2196,9 +2202,14 @@ class TestRequests:
         # These are all possible acceptable combinations for the header.
         fruit_choices = ['Apple', 'Blood Orange', 'Banana', 'Berry, Blue']
         fruit_permutations = itertools.permutations(fruit_choices)
-        fruit_headers = set(', '.join(fp) for fp in fruit_permutations)
+        fruit_multiheaders = set(tuple(fp) for fp in fruit_permutations)
+        fruit_headers = set(', '.join(fp) for fp in fruit_multiheaders)
         assert resp.headers['fruit'] in fruit_headers
 
+        # As we are using HTTPHeaderDict, we should be able to extract the
+        # individual header values too.
+        assert resp.headers.multiget('fruit') in fruit_multiheaders
+
 
 class TestCaseInsensitiveDict: