don't use a slot wrapper from a different special method (closes #14658)

benjaminp · benjaminp · commit 7b1668735ace · 2012-04-24T11:06:25.000-04:00
This also alters the fix to #11603. Specifically, setting __repr__ to object.__str__ now raises a recursion RuntimeError when str() or repr() is called instead of silently bypassing the recursion. I believe this behavior is more correct.
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
@@ -4430,7 +4430,15 @@ class Foo:
             pass
         Foo.__repr__ = Foo.__str__
         foo = Foo()
-        str(foo)
+        self.assertRaises(RuntimeError, str, foo)
+        self.assertRaises(RuntimeError, repr, foo)
+
+    def test_mixing_slot_wrappers(self):
+        class X(dict):
+            __setattr__ = dict.__setitem__
+        x = X()
+        x.y = 42
+        self.assertEqual(x["y"], 42)
 
     def test_cycle_through_dict(self):
         # See bug #1469629
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -10,6 +10,12 @@ What's New in Python 3.2.4
 Core and Builtins
 -----------------
 
+- Issue #11603 (again): Setting __repr__ to __str__ now raises a RuntimeError
+  when repr() or str() is called on such an object.
+
+- Issue #14658: Fix binding a special method to a builtin implementation of a
+  special method with a different name.
+
 - Issue #14630: Fix a memory access bug for instances of a subclass of int
   with value 0.
 
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
@@ -2928,7 +2928,7 @@ object_str(PyObject *self)
     unaryfunc f;
 
     f = Py_TYPE(self)->tp_repr;
-    if (f == NULL || f == object_str)
+    if (f == NULL)
         f = object_repr;
     return f(self);
 }
@@ -5757,7 +5757,8 @@ update_one_slot(PyTypeObject *type, slotdef *p)
             }
             continue;
         }
-        if (Py_TYPE(descr) == &PyWrapperDescr_Type) {
+        if (Py_TYPE(descr) == &PyWrapperDescr_Type &&
+            ((PyWrapperDescrObject *)descr)->d_base->name_strobj == p->name_strobj) {
             void **tptr = resolve_slotdups(type, p->name_strobj);
             if (tptr == NULL || tptr == ptr)
                 generic = p->function;

Original file line number	Diff line number	Diff line change
`@@ -2928,7 +2928,7 @@ object_str(PyObject *self)`
`2928`	`2928`	`unaryfunc f;`
`2929`	`2929`
`2930`	`2930`	`f = Py_TYPE(self)->tp_repr;`
`2931`		`- if (f == NULL \|\| f == object_str)`
	`2931`	`+ if (f == NULL)`
`2932`	`2932`	`f = object_repr;`
`2933`	`2933`	`return f(self);`
`2934`	`2934`	`}`
`@@ -5757,7 +5757,8 @@ update_one_slot(PyTypeObject type, slotdef p)`
`5757`	`5757`	`}`
`5758`	`5758`	`continue;`
`5759`	`5759`	`}`
`5760`		`- if (Py_TYPE(descr) == &PyWrapperDescr_Type) {`
	`5760`	`+ if (Py_TYPE(descr) == &PyWrapperDescr_Type &&`
	`5761`	`+ ((PyWrapperDescrObject *)descr)->d_base->name_strobj == p->name_strobj) {`
`5761`	`5762`	`void **tptr = resolve_slotdups(type, p->name_strobj);`
`5762`	`5763`	`if (tptr == NULL \|\| tptr == ptr)`
`5763`	`5764`	`generic = p->function;`