[Bug #1576241] Let functools.wraps work with built-in functions

diff --git a/Lib/functools.py b/Lib/functools.py
index 1fafb0199a8843ebf8526770adf42494dcd8cad0..bb13713a9c869b7f60a8dec91111085318c46561 100644 (file)
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -32,7 +32,7 @@ def update_wrapper(wrapper,
     for attr in assigned:
         setattr(wrapper, attr, getattr(wrapped, attr))
     for attr in updated:
-        getattr(wrapper, attr).update(getattr(wrapped, attr))
+        getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
     # Return the wrapper so this can be used as a decorator via partial()
     return wrapper
 

diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 8dc185b721033844b6c24fc338c9f3c13890157c..6012f9f8551803eb4ef7c3c2716c70f51974b457 100644 (file)
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -210,6 +210,13 @@ class TestUpdateWrapper(unittest.TestCase):
         self.assertEqual(wrapper.attr, 'This is a different test')
         self.assertEqual(wrapper.dict_attr, f.dict_attr)
 
+    def test_builtin_update(self):
+        # Test for bug #1576241
+        def wrapper():
+            pass
+        functools.update_wrapper(wrapper, max)
+        self.assertEqual(wrapper.__name__, 'max')
+        self.assert_(wrapper.__doc__.startswith('max('))
 
 class TestWraps(TestUpdateWrapper):