From da2cf04c2807e3b2f80e06306242238ddddaa260 Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Sat, 5 Jun 2010 00:45:37 +0000
Subject: [PATCH] Merged revisions 81706-81707 via svnmerge from
 svn+ssh://pythondev@svn.python.org/python/trunk

........
  r81706 | benjamin.peterson | 2010-06-04 19:32:50 -0500 (Fri, 04 Jun 2010) | 1 line

  properly lookup the __format__ special method
........
  r81707 | benjamin.peterson | 2010-06-04 19:38:22 -0500 (Fri, 04 Jun 2010) | 1 line

  remove PyType_Ready call; float should be initialized in interpreter startup
........
---
 Lib/test/test_descr.py |  3 +++
 Objects/abstract.c     | 42 +++++++++++++++---------------------------
 2 files changed, 18 insertions(+), 27 deletions(-)

diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 5568dd5e279..10820ab712e 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1557,6 +1557,8 @@ order (MRO) for bases """
             self.assertEqual(key, "hi")
             return 4
         def swallow(*args): pass
+        def format_impl(self, spec):
+            return "hello"
 
         # It would be nice to have every special method tested here, but I'm
         # only listing the ones I can remember outside of typeobject.c, since it
@@ -1575,6 +1577,7 @@ order (MRO) for bases """
             ("__enter__", run_context, iden, set(), {"__exit__" : swallow}),
             ("__exit__", run_context, swallow, set(), {"__enter__" : iden}),
             ("__complex__", complex, complex_num, set(), {}),
+            ("__format__", format, format_impl, set(), {}),
             ]
 
         class Checker(object):
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 5a904b44d12..1b6c2b42796 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -693,48 +693,36 @@ PyBuffer_Release(Py_buffer *view)
 PyObject *
 PyObject_Format(PyObject *obj, PyObject *format_spec)
 {
-    static PyObject * str__format__ = NULL;
     PyObject *meth;
     PyObject *empty = NULL;
     PyObject *result = NULL;
-
-    /* Initialize cached value */
-    if (str__format__ == NULL) {
-    /* Initialize static variable needed by _PyType_Lookup */
-    str__format__ = PyUnicode_FromString("__format__");
-    if (str__format__ == NULL)
-        goto done;
-    }
+    static PyObject *format_cache = NULL;
 
     /* If no format_spec is provided, use an empty string */
     if (format_spec == NULL) {
-    empty = PyUnicode_FromUnicode(NULL, 0);
-    format_spec = empty;
+        empty = PyUnicode_FromUnicode(NULL, 0);
+        format_spec = empty;
     }
 
-    /* Make sure the type is initialized.  float gets initialized late */
-    if (Py_TYPE(obj)->tp_dict == NULL)
-    if (PyType_Ready(Py_TYPE(obj)) < 0)
-        goto done;
-
     /* Find the (unbound!) __format__ method (a borrowed reference) */
-    meth = _PyType_Lookup(Py_TYPE(obj), str__format__);
+    meth = _PyObject_LookupSpecial(obj, "__format__", &format_cache);
     if (meth == NULL) {
-    PyErr_Format(PyExc_TypeError,
-        "Type %.100s doesn't define __format__",
-        Py_TYPE(obj)->tp_name);
+        if (!PyErr_Occurred())
+            PyErr_Format(PyExc_TypeError,
+                         "Type %.100s doesn't define __format__",
+                         Py_TYPE(obj)->tp_name);
         goto done;
     }
 
-    /* And call it, binding it to the value */
-    result = PyObject_CallFunctionObjArgs(meth, obj, format_spec, NULL);
+    /* And call it. */
+    result = PyObject_CallFunctionObjArgs(meth, format_spec, NULL);
 
     if (result && !PyUnicode_Check(result)) {
-    PyErr_SetString(PyExc_TypeError,
-        "__format__ method did not return string");
-    Py_DECREF(result);
-    result = NULL;
-    goto done;
+        PyErr_SetString(PyExc_TypeError,
+                        "__format__ method did not return string");
+        Py_DECREF(result);
+        result = NULL;
+        goto done;
     }
 
 done: