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

3 files changed, 10 insertions, 1 deletions

diff --git a/Lib/functools.py b/Lib/functools.py
index 8783f08488..96430365c9 100644
--- 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 8dc185b721..6012f9f855 100644
--- 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):
 
diff --git a/Misc/NEWS b/Misc/NEWS
index a1033bf378..13f52a78e7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -105,6 +105,8 @@ Library
 - Bug #1565661: in webbrowser, split() the command for the default
   GNOME browser in case it is a command with args.
 
+- Bug #1576241: fix functools.wraps() to work on built-in functions.
+
 - Fix a bug in traceback.format_exception_only() that led to an error
   being raised when print_exc() was called without an exception set.
   In version 2.4, this printed "None", restored that behavior.