Fixed #9221 -- Small optimisation to caching middleware handling.

In the slightly unusual case that CACHE_MIDDLEWARE_SECONDS is set to 0, don't
bother storing a copy in the local cache.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@9098 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/middleware/cache.py

@@ -89,6 +89,7 @@ class UpdateCacheMiddleware(object):
             # max-age was set to 0, don't bother caching.
             return response
         patch_response_headers(response, timeout)
+        if timeout:
             cache_key = learn_cache_key(request, response, timeout, self.key_prefix)
             cache.set(cache_key, response, timeout)
         return response