--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/http/utils.py	Wed Jan 20 00:34:04 2010 +0100
@@ -0,0 +1,84 @@
+"""
+Functions that modify an HTTP request or response in some way.
+"""
+
+# This group of functions are run as part of the response handling, after
+# everything else, including all response middleware. Think of them as
+# "compulsory response middleware". Be careful about what goes here, because
+# it's a little fiddly to override this behavior, so they should be truly
+# universally applicable.
+
+def fix_location_header(request, response):
+    """
+    Ensures that we always use an absolute URI in any location header in the
+    response. This is required by RFC 2616, section 14.30.
+
+    Code constructing response objects is free to insert relative paths, as
+    this function converts them to absolute paths.
+    """
+    if 'Location' in response and request.get_host():
+        response['Location'] = request.build_absolute_uri(response['Location'])
+    return response
+
+def conditional_content_removal(request, response):
+    """
+    Removes the content of responses for HEAD requests, 1xx, 204 and 304
+    responses. Ensures compliance with RFC 2616, section 4.3.
+    """
+    if 100 <= response.status_code < 200 or response.status_code in (204, 304):
+       response.content = ''
+       response['Content-Length'] = 0
+    if request.method == 'HEAD':
+        response.content = ''
+    return response
+
+def fix_IE_for_attach(request, response):
+    """
+    This function will prevent Django from serving a Content-Disposition header
+    while expecting the browser to cache it (only when the browser is IE). This
+    leads to IE not allowing the client to download.
+    """
+    if 'MSIE' not in request.META.get('HTTP_USER_AGENT', '').upper():
+        return response
+
+    offending_headers = ('no-cache', 'no-store')
+    if response.has_header('Content-Disposition'):
+        try:
+            del response['Pragma']
+        except KeyError:
+            pass
+        if response.has_header('Cache-Control'):
+            cache_control_values = [value.strip() for value in
+                    response['Cache-Control'].split(',')
+                    if value.strip().lower() not in offending_headers]
+
+            if not len(cache_control_values):
+                del response['Cache-Control']
+            else:
+                response['Cache-Control'] = ', '.join(cache_control_values)
+
+    return response
+
+def fix_IE_for_vary(request, response):
+    """
+    This function will fix the bug reported at
+    http://support.microsoft.com/kb/824847/en-us?spid=8722&sid=global
+    by clearing the Vary header whenever the mime-type is not safe
+    enough for Internet Explorer to handle.  Poor thing.
+    """
+    if 'MSIE' not in request.META.get('HTTP_USER_AGENT', '').upper():
+        return response
+
+    # These mime-types that are decreed "Vary-safe" for IE:
+    safe_mime_types = ('text/html', 'text/plain', 'text/sgml')
+
+    # The first part of the Content-Type field will be the MIME type,
+    # everything after ';', such as character-set, can be ignored.
+    if response['Content-Type'].split(';')[0] not in safe_mime_types:
+        try:
+            del response['Vary']
+        except KeyError:
+            pass
+
+    return response
+