From baf0f8f24da7a541a403cd9848cebc451beb069d Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Sat, 22 Nov 2003 23:55:50 +0000
Subject: [PATCH] - When method objects have an attribute that can be satisfied
 either   by the function object or by the method object, the function  
 object's attribute usually wins.  Christian Tismer pointed out that   that
 this is really a mistake, because this only happens for special   methods
 (like __reduce__) where the method object's version is   really more
 appropriate than the function's attribute.  So from now   on, all method
 attributes will have precedence over function   attributes with the same
 name.

---
 Misc/NEWS             |  9 +++++++
 Objects/classobject.c | 58 ++++++++++++++++++++++---------------------
 2 files changed, 39 insertions(+), 28 deletions(-)

diff --git a/Misc/NEWS b/Misc/NEWS
index 30fe4be67f8..f7b1e96710f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,15 @@ What's New in Python 2.4 alpha 1?
 Core and builtins
 -----------------
 
+- When method objects have an attribute that can be satisfied either
+  by the function object or by the method object, the function
+  object's attribute usually wins.  Christian Tismer pointed out that
+  that this is really a mistake, because this only happens for special
+  methods (like __reduce__) where the method object's version is
+  really more appropriate than the function's attribute.  So from now
+  on, all method attributes will have precedence over function
+  attributes with the same name.
+
 - Critical bugfix, for SF bug 839548:  if a weakref with a callback,
   its callback, and its weakly referenced object, all became part of
   cyclic garbage during a single run of garbage collection, the order
diff --git a/Objects/classobject.c b/Objects/classobject.c
index 84b297cad95..17a56467817 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -2138,19 +2138,34 @@ static PyMemberDef instancemethod_memberlist[] = {
 	{NULL}	/* Sentinel */
 };
 
-/* The getattr() implementation for PyMethod objects is similar to
-   PyObject_GenericGetAttr(), but instead of looking in __dict__ it
-   asks im_self for the attribute.  Then the error handling is a bit
-   different because we want to preserve the exception raised by the
-   delegate, unless we have an alternative from our class. */
+/* Christian Tismer argued convincingly that method attributes should
+   (nearly) always override function attributes.
+   The one exception is __doc__; there's a default __doc__ which
+   should only be used for the class, not for instances */
+
+static PyObject *
+instancemethod_get_doc(PyMethodObject *im, void *context)
+{
+	static PyObject *docstr;
+	if (docstr == NULL) {
+		docstr= PyString_InternFromString("__doc__");
+		if (docstr == NULL)
+			return NULL;
+	}
+	return PyObject_GetAttr(im->im_func, docstr);
+}
+
+static PyGetSetDef instancemethod_getset[] = {
+	{"__doc__", (getter)instancemethod_get_doc, NULL, NULL},
+	{0}
+};
 
 static PyObject *
 instancemethod_getattro(PyObject *obj, PyObject *name)
 {
 	PyMethodObject *im = (PyMethodObject *)obj;
 	PyTypeObject *tp = obj->ob_type;
-	PyObject *descr = NULL, *res;
-	descrgetfunc f = NULL;
+	PyObject *descr = NULL;
 
 	if (PyType_HasFeature(tp, Py_TPFLAGS_HAVE_CLASS)) {
 		if (tp->tp_dict == NULL) {
@@ -2160,30 +2175,17 @@ instancemethod_getattro(PyObject *obj, PyObject *name)
 		descr = _PyType_Lookup(tp, name);
 	}
 
-	f = NULL;
 	if (descr != NULL) {
-		f = TP_DESCR_GET(descr->ob_type);
-		if (f != NULL && PyDescr_IsData(descr))
+		descrgetfunc f = TP_DESCR_GET(descr->ob_type);
+		if (f != NULL)
 			return f(descr, obj, (PyObject *)obj->ob_type);
+		else {
+			Py_INCREF(descr);
+			return descr;
+		}
 	}
 
-	res = PyObject_GetAttr(im->im_func, name);
-	if (res != NULL || !PyErr_ExceptionMatches(PyExc_AttributeError))
-		return res;
-
-	if (f != NULL) {
-		PyErr_Clear();
-		return f(descr, obj, (PyObject *)obj->ob_type);
-	}
-
-	if (descr != NULL) {
-		PyErr_Clear();
-		Py_INCREF(descr);
-		return descr;
-	}
-
-	assert(PyErr_Occurred());
-	return NULL;
+	return PyObject_GetAttr(im->im_func, name);
 }
 
 PyDoc_STRVAR(instancemethod_doc,
@@ -2490,7 +2492,7 @@ PyTypeObject PyMethod_Type = {
 	0,					/* tp_iternext */
 	0,					/* tp_methods */
 	instancemethod_memberlist,		/* tp_members */
-	0,					/* tp_getset */
+	instancemethod_getset,			/* tp_getset */
 	0,					/* tp_base */
 	0,					/* tp_dict */
 	instancemethod_descr_get,		/* tp_descr_get */