Fixed #717 - If-Modified-Since handling should compare dates according to RFC 2616

Thanks to Maniac for the report, julienb for the initial patch, and
especially to aaugustin for the final patch and tests.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15696 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/middleware/tests.py

@@ -3,6 +3,7 @@
 from django.conf import settings
 from django.http import HttpRequest
 from django.middleware.common import CommonMiddleware
+from django.middleware.http import ConditionalGetMiddleware
 from django.test import TestCase
 
 
@@ -247,3 +248,89 @@ class CommonMiddlewareTest(TestCase):
       self.assertEquals(r.status_code, 301)
       self.assertEquals(r['Location'],
                         'http://www.testserver/middleware/customurlconf/slash/')
+
+class ConditionalGetMiddlewareTest(TestCase):
+    urls = 'regressiontests.middleware.cond_get_urls'
+    def setUp(self):
+        self.req = HttpRequest()
+        self.req.META = {
+            'SERVER_NAME': 'testserver',
+            'SERVER_PORT': 80,
+        }
+        self.req.path = self.req.path_info = "/"
+        self.resp = self.client.get(self.req.path)
+
+    # Tests for the Date header
+
+    def test_date_header_added(self):
+        self.assertFalse('Date' in self.resp)
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertTrue('Date' in self.resp)
+
+    # Tests for the Content-Length header
+
+    def test_content_length_header_added(self):
+        content_length = len(self.resp.content)
+        self.assertFalse('Content-Length' in self.resp)
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertTrue('Content-Length' in self.resp)
+        self.assertEqual(int(self.resp['Content-Length']), content_length)
+
+    def test_content_length_header_not_changed(self):
+        bad_content_length = len(self.resp.content) + 10
+        self.resp['Content-Length'] = bad_content_length
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEqual(int(self.resp['Content-Length']), bad_content_length)
+
+    # Tests for the ETag header
+
+    def test_if_none_match_and_no_etag(self):
+        self.req.META['HTTP_IF_NONE_MATCH'] = 'spam'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 200)
+
+    def test_no_if_none_match_and_etag(self):
+        self.resp['ETag'] = 'eggs'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 200)
+
+    def test_if_none_match_and_same_etag(self):
+        self.req.META['HTTP_IF_NONE_MATCH'] = self.resp['ETag'] = 'spam'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 304)
+
+    def test_if_none_match_and_different_etag(self):
+        self.req.META['HTTP_IF_NONE_MATCH'] = 'spam'
+        self.resp['ETag'] = 'eggs'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 200)
+
+    # Tests for the Last-Modified header
+
+    def test_if_modified_since_and_no_last_modified(self):
+        self.req.META['HTTP_IF_MODIFIED_SINCE'] = 'Sat, 12 Feb 2011 17:38:44 GMT'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 200)
+
+    def test_no_if_modified_since_and_last_modified(self):
+        self.resp['Last-Modified'] = 'Sat, 12 Feb 2011 17:38:44 GMT'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 200)
+
+    def test_if_modified_since_and_same_last_modified(self):
+        self.req.META['HTTP_IF_MODIFIED_SINCE'] = 'Sat, 12 Feb 2011 17:38:44 GMT'
+        self.resp['Last-Modified'] = 'Sat, 12 Feb 2011 17:38:44 GMT'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 304)
+
+    def test_if_modified_since_and_last_modified_in_the_past(self):
+        self.req.META['HTTP_IF_MODIFIED_SINCE'] = 'Sat, 12 Feb 2011 17:38:44 GMT'
+        self.resp['Last-Modified'] = 'Sat, 12 Feb 2011 17:35:44 GMT'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 304)
+
+    def test_if_modified_since_and_last_modified_in_the_future(self):
+        self.req.META['HTTP_IF_MODIFIED_SINCE'] = 'Sat, 12 Feb 2011 17:38:44 GMT'
+        self.resp['Last-Modified'] = 'Sat, 12 Feb 2011 17:41:44 GMT'
+        self.resp = ConditionalGetMiddleware().process_response(self.req, self.resp)
+        self.assertEquals(self.resp.status_code, 200)