Ticket #5047: patch_cache_controll.diff

django/utils/cache.py

@@ -27 +27 @@
 
 cc_delim_re = re.compile(r'\s*,\s*')
 
-def patch_cache_control(response, **kwargs):
+def patch_cache_control(response, rewrite = True, **kwargs):
     """
     This function patches the Cache-Control header by adding all
     keyword arguments to it. The transformation is as follows:
 
+    * If rewrite set to False, then value 'max-age' in current Cache-Control
+      header remains untouched, otherwise it could be rewritten by value from
+      kwargs
     * All keyword parameter names are turned to lowercase, and underscores
       are converted to hyphens.
     * If the value of a parameter is True (exactly True, not just a
@@ -57 +60 @@
         cc = dict([dictitem(el) for el in cc])
     else:
         cc = {}
+
+    if not rewrite and 'max-age' in cc and 'max_age' in kwargs:
+        del kwargs['max_age']
+
     for (k,v) in kwargs.items():
         cc[k.replace('_', '-')] = v
     cc = ', '.join([dictvalue(el) for el in cc.items()])
@@ -84 +91 @@
         response['Last-Modified'] = formatdate()[:26] + "GMT"
     if not response.has_header('Expires'):
         response['Expires'] = formatdate(time.time() + cache_timeout)[:26] + "GMT"
-    patch_cache_control(response, max_age=cache_timeout)
+    patch_cache_control(response, rewrite = False, max_age=cache_timeout)
 
 def add_never_cache_headers(response):
     """