Ticket #4148: 5065-fix_ie_error_bug__for_4148.diff

django/middleware/fixievarybug.py

@@ +1 @@
+class FixIEVaryBugMiddleware(object):
+    """
+    Quick MiddleWare that will fix the bug reported at
+    http://support.microsoft.com/kb/824847/en-us?spid=8722&sid=global (thanks aconbere)
+    for Internet Explorer since Microsoft doesn't know how to do HTTP.
+
+    To use: Make sure you put this at the *beginning* of your middleware
+    list (since Django applies responses in reverse order).
+    """
+
+    def process_response(self, request, response):
+
+        # a list of mime-types that are decreed "Vary-safe" for IE
+        safe_mime_types = ('text/html',
+                           'text/plain',
+                           'text/sgml',
+                           )
+
+        # establish that the user is using IE
+        try:
+            if 'MSIE' not in request.META['User-Agent'].upper():
+                return response
+        except KeyError:
+            return response
+
+
+        # IE will break
+        if response.mimetype.lower() not in safe_mime_types: 
+            try:
+                del response['Vary']
+                response['Pragma'] = 'no-cache'
+                response['Cache-Control'] = 'no-cache, must-revalidate'
+            except KeyError:
+                return response
+
+        return response
+        

docs/middleware.txt

@@ -116 +116 @@
 ``HTTP_X_FORWARDED_FOR``, that means anybody can "fake" their IP address. Only
 use this when you can absolutely trust the value of ``HTTP_X_FORWARDED_FOR``.
 
+django.middleware.fixievarybug.FixIEVaryBugMiddleware
+-----------------------------------------------------
+
+Fixes the Internet Explorer (IE) vary bug described at
+http://support.microsoft.com/kb/824847/en-us?spid=8722&sid=global. If you are
+generating PDF files and you expect IE to work with your site, just enable
+this middleware.
+
 django.contrib.sessions.middleware.SessionMiddleware
 ----------------------------------------------------