Ensure that instances of 'AllPermissionsList' are iterable.

Cherry pick 1814cda from master.

Closes #3073.

pyramid/security.py

@@ -21,10 +21,13 @@
 
 class AllPermissionsList(object):
     """ Stand in 'permission list' to represent all permissions """
+
     def __iter__(self):
-        return ()
+        return iter(())
+
     def __contains__(self, other):
         return True
+
     def __eq__(self, other):
         return isinstance(other, self.__class__)
 

pyramid/tests/test_security.py

@@ -16,12 +16,32 @@ def _getTargetClass(self):
     def _makeOne(self):
         return self._getTargetClass()()
 
-    def test_it(self):
+    def test_equality_w_self(self):
         thing = self._makeOne()
         self.assertTrue(thing.__eq__(thing))
-        self.assertEqual(thing.__iter__(), ())
+
+    def test_equality_w_other_instances_of_class(self):
+        thing = self._makeOne()
+        other = self._makeOne()
+        self.assertTrue(thing.__eq__(other))
+
+    def test_equality_miss(self):
+        thing = self._makeOne()
+        other = object()
+        self.assertFalse(thing.__eq__(other))
+
+    def test_contains_w_string(self):
+        thing = self._makeOne()
         self.assertTrue('anything' in thing)
 
+    def test_contains_w_object(self):
+        thing = self._makeOne()
+        self.assertTrue(object() in thing)
+
+    def test_iterable(self):
+        thing = self._makeOne()
+        self.assertEqual(list(thing), [])
+
     def test_singleton(self):
         from pyramid.security import ALL_PERMISSIONS
         self.assertEqual(ALL_PERMISSIONS.__class__, self._getTargetClass())