Fixed #17552 -- Removed a hack for IE6 and earlier.

It prevented the GZipMiddleware from compressing some data types even on
more recent version of IE where the corresponding bug was fixed.

Thanks Aaron Cannon for the report and Tim Graham for the review.

django/middleware/gzip.py

@@ -17,17 +17,11 @@ class GZipMiddleware(object):
         if not response.streaming and len(response.content) < 200:
             return response
 
-        patch_vary_headers(response, ('Accept-Encoding',))
-
         # Avoid gzipping if we've already got a content-encoding.
         if response.has_header('Content-Encoding'):
             return response
 
-        # MSIE have issues with gzipped response of various content types.
+        patch_vary_headers(response, ('Accept-Encoding',))
-        if "msie" in request.META.get('HTTP_USER_AGENT', '').lower():
-            ctype = response.get('Content-Type', '').lower()
-            if not ctype.startswith("text/") or "javascript" in ctype:
-                return response
 
         ae = request.META.get('HTTP_ACCEPT_ENCODING', '')
         if not re_accepts_gzip.search(ae):

docs/ref/middleware.txt

@@ -108,11 +108,6 @@ It will NOT compress content if any of the following are true:
 * The request (the browser) hasn't sent an ``Accept-Encoding`` header
   containing ``gzip``.
 
-* The request is from Internet Explorer and the ``Content-Type`` header
-  contains ``javascript`` or starts with anything other than ``text/``.
-  We do this to avoid a bug in early versions of IE that caused decompression
-  not to be performed on certain content types.
-
 You can apply GZip compression to individual views using the
 :func:`~django.views.decorators.gzip.gzip_page()` decorator.
 

docs/releases/1.8.txt

@@ -273,6 +273,11 @@ Miscellaneous
 * Database connections are considered equal only if they're the same object.
   They aren't hashable any more.
 
+* :class:`~django.middleware.gzip.GZipMiddleware` used to disable compression
+  for some content types when the request is from Internet Explorer, in order
+  to work around a bug in IE6 and earlier. This behavior could affect
+  performance on IE7 and later. It was removed.
+
 * ``URLField.to_python`` no longer adds a trailing slash to pathless URLs.
 
 * ``django.contrib.gis`` dropped support for GEOS 3.1 and GDAL 1.6.

tests/middleware/tests.py

@@ -613,16 +613,6 @@ class GZipMiddlewareTest(TestCase):
         self.assertEqual(r.content, self.compressible_string)
         self.assertEqual(r.get('Content-Encoding'), 'deflate')
 
-    def test_no_compress_ie_js_requests(self):
-        """
-        Tests that compression isn't performed on JavaScript requests from Internet Explorer.
-        """
-        self.req.META['HTTP_USER_AGENT'] = 'Mozilla/4.0 (compatible; MSIE 5.00; Windows 98)'
-        self.resp['Content-Type'] = 'application/javascript; charset=UTF-8'
-        r = GZipMiddleware().process_response(self.req, self.resp)
-        self.assertEqual(r.content, self.compressible_string)
-        self.assertEqual(r.get('Content-Encoding'), None)
-
     def test_no_compress_uncompressible_response(self):
         """
         Tests that compression isn't performed on responses with uncompressible content.