From 43bd3cd55952938176d7c5820f5fcabf25d36ec3 Mon Sep 17 00:00:00 2001
From: Graham Dumpleton <Graham.Dumpleton@gmail.com>
Date: Sat, 21 Sep 2013 21:16:20 +1000
Subject: [PATCH] Raise TypeError when attempt to delete __wrapped__ on pure
 Python implementation and del/update __qualname__ when __wrapped__ set.

---
 src/wrappers.py            | 23 +++++++++++++++++++++--
 tests/test_object_proxy.py | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/src/wrappers.py b/src/wrappers.py
index 171cb36..125f507 100644
--- a/src/wrappers.py
+++ b/src/wrappers.py
@@ -129,11 +129,25 @@ class ObjectProxy(six.with_metaclass(_ObjectProxyMetaType)):
         return bool(self.__wrapped__)
 
     def __setattr__(self, name, value):
-        if name.startswith('_self_') or name == '__wrapped__':
+        if name.startswith('_self_'):
             object.__setattr__(self, name, value)
+
+        elif name == '__wrapped__':
+            object.__setattr__(self, name, value)
+            try:
+                object.__delattr__(self, '__qualname__')
+            except AttributeError:
+                pass
+            object.__setattr__(self, name, value)
+            try:
+                object.__setattr__(self, '__qualname__', value.__qualname__)
+            except AttributeError:
+                pass
+
         elif name == '__qualname__':
             setattr(self.__wrapped__, name, value)
             object.__setattr__(self, name, value)
+
         else:
             setattr(self.__wrapped__, name, value)
 
@@ -141,11 +155,16 @@ class ObjectProxy(six.with_metaclass(_ObjectProxyMetaType)):
         return getattr(self.__wrapped__, name)
 
     def __delattr__(self, name):
-        if name.startswith('_self_') or name == '__wrapped__':
+        if name.startswith('_self_'):
             object.__delattr__(self, name)
+
+        elif name == '__wrapped__':
+            raise TypeError('__wrapped__ must be an object')
+
         elif name == '__qualname__':
             object.__delattr__(self, name)
             delattr(self.__wrapped__, name)
+
         else:
             delattr(self.__wrapped__, name)
 
diff --git a/tests/test_object_proxy.py b/tests/test_object_proxy.py
index 11809d5..ca4c900 100644
--- a/tests/test_object_proxy.py
+++ b/tests/test_object_proxy.py
@@ -51,14 +51,46 @@ class TestAttributeAccess(unittest.TestCase):
             return args, kwargs
         function2 = wrapt.ObjectProxy(function1)
 
+        self.assertEqual(function2, function1)
         self.assertEqual(function2.__wrapped__, function1)
+        self.assertEqual(function2.__name__, function1.__name__)
+
+        if six.PY3:
+            self.assertEqual(function2.__qualname__, function1.__qualname__)
 
         function2.__wrapped__ = None
 
-        self.assertEqual(function2.__wrapped__, None)
-
         self.assertFalse(hasattr(function1, '__wrapped__'))
 
+        self.assertEqual(function2, None)
+        self.assertEqual(function2.__wrapped__, None)
+        self.assertFalse(hasattr(function2, '__name__'))
+
+        if six.PY3:
+            self.assertFalse(hasattr(function2, '__qualname__'))
+
+        def function3(*args, **kwargs):
+            return args, kwargs
+
+        function2.__wrapped__ = function3
+
+        self.assertEqual(function2, function3)
+        self.assertEqual(function2.__wrapped__, function3)
+        self.assertEqual(function2.__name__, function3.__name__)
+
+        if six.PY3:
+            self.assertEqual(function2.__qualname__, function3.__qualname__)
+
+    def test_delete_wrapped(self):
+        def function1(*args, **kwargs):
+            return args, kwargs
+        function2 = wrapt.ObjectProxy(function1)
+
+        def run(*args):
+            del function2.__wrapped__
+
+        self.assertRaises(TypeError, run, ())
+
     def test_proxy_attribute(self):
         def function1(*args, **kwargs):
             return args, kwargs