From e6ad4fb901c4d3bbaff1ad01bb8cc93852c20e1e Mon Sep 17 00:00:00 2001
From: Jacob Kaplan-Moss <jacob@jacobian.org>
Date: Wed, 1 Apr 2009 16:17:38 +0000
Subject: [PATCH] Fixed #9474: user_passes_test may now be applied multiple
 times.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10328 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/contrib/auth/decorators.py         | 13 +++++++++-
 tests/regressiontests/decorators/tests.py | 31 +++++++++++++++++++++++
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/django/contrib/auth/decorators.py b/django/contrib/auth/decorators.py
index 1371c62eea..b80aca10a3 100644
--- a/django/contrib/auth/decorators.py
+++ b/django/contrib/auth/decorators.py
@@ -56,8 +56,19 @@ class _CheckLogin(object):
         self.test_func = test_func
         self.login_url = login_url
         self.redirect_field_name = redirect_field_name
-        update_wrapper(self, view_func)
         
+        # We can't blindly apply update_wrapper because it udpates __dict__ and 
+        # if the view function is already a _CheckLogin object then 
+        # self.test_func and friends will get stomped. However, we also can't 
+        # *not* update the wrapper's dict because then view function attributes
+        # don't get updated into the wrapper. So we need to split the
+        # difference: don't let update_wrapper update __dict__, but then update
+        # the (parts of) __dict__ that we care about ourselves.
+        update_wrapper(self, view_func, updated=())
+        for k in view_func.__dict__:
+            if k not in self.__dict__:
+                self.__dict__[k] = view_func.__dict__[k]
+
     def __get__(self, obj, cls=None):
         view_func = self.view_func.__get__(obj, cls)
         return _CheckLogin(view_func, self.test_func, self.login_url, self.redirect_field_name)
diff --git a/tests/regressiontests/decorators/tests.py b/tests/regressiontests/decorators/tests.py
index 0c434772f8..3c58637f1a 100644
--- a/tests/regressiontests/decorators/tests.py
+++ b/tests/regressiontests/decorators/tests.py
@@ -29,6 +29,7 @@ fully_decorated = cache_control(private=True)(fully_decorated)
 fully_decorated = never_cache(fully_decorated)
 
 # django.contrib.auth.decorators
+# Apply user_passes_test twice to check #9474
 fully_decorated = user_passes_test(lambda u:True)(fully_decorated)
 fully_decorated = login_required(fully_decorated)
 fully_decorated = permission_required('change_world')(fully_decorated)
@@ -54,3 +55,33 @@ class DecoratorsTest(TestCase):
             self.assertEquals(fully_decorated.__name__, 'fully_decorated')
         self.assertEquals(fully_decorated.__doc__, 'Expected __doc__')
         self.assertEquals(fully_decorated.__dict__['anything'], 'Expected __dict__')
+
+    def test_user_passes_test_composition(self):
+        """
+        Test that the user_passes_test decorator can be applied multiple times
+        (#9474).
+        """
+        def test1(user):
+            user.decorators_applied.append('test1')
+            return True
+            
+        def test2(user):
+            user.decorators_applied.append('test2')
+            return True
+            
+        def callback(request):
+            return request.user.decorators_applied
+
+        callback = user_passes_test(test1)(callback)
+        callback = user_passes_test(test2)(callback)
+        
+        class DummyUser(object): pass
+        class DummyRequest(object): pass
+        
+        request = DummyRequest()
+        request.user = DummyUser()
+        request.user.decorators_applied = []
+        response = callback(request)
+        
+        self.assertEqual(response, ['test2', 'test1'])
+