SF patch #1390657:
* set sq_repeat and sq_concat to NULL for user-defined new-style
classes, as a way to fix a number of related problems. See
test_descr.notimplemented()). One of these problems was fixed
in r25556 and r25557 but many more existed; this is a general
fix and thus reverts r25556-r25557.
* to avoid having PySequence_Repeat()/PySequence_Concat() failing
on user-defined classes, they now fall back to nb_add/nb_mul if
sq_concat/sq_repeat are not defined and the arguments appear to
be sequences.
* added tests.
Backport candidate.
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 1f8feb5..6e070a9 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -635,14 +635,11 @@
PyObject *result = binary_op1(v, w, NB_SLOT(nb_add));
if (result == Py_NotImplemented) {
PySequenceMethods *m = v->ob_type->tp_as_sequence;
+ Py_DECREF(result);
if (m && m->sq_concat) {
- Py_DECREF(result);
- result = (*m->sq_concat)(v, w);
+ return (*m->sq_concat)(v, w);
}
- if (result == Py_NotImplemented) {
- Py_DECREF(result);
- return binop_type_error(v, w, "+");
- }
+ result = binop_type_error(v, w, "+");
}
return result;
}
@@ -1144,6 +1141,15 @@
if (m && m->sq_concat)
return m->sq_concat(s, o);
+ /* Instances of user classes defining an __add__() method only
+ have an nb_add slot, not an sq_concat slot. So we fall back
+ to nb_add if both arguments appear to be sequences. */
+ if (PySequence_Check(s) && PySequence_Check(o)) {
+ PyObject *result = binary_op1(s, o, NB_SLOT(nb_add));
+ if (result != Py_NotImplemented)
+ return result;
+ Py_DECREF(result);
+ }
return type_error("object can't be concatenated");
}
@@ -1159,6 +1165,20 @@
if (m && m->sq_repeat)
return m->sq_repeat(o, count);
+ /* Instances of user classes defining a __mul__() method only
+ have an nb_multiply slot, not an sq_repeat slot. so we fall back
+ to nb_multiply if o appears to be a sequence. */
+ if (PySequence_Check(o)) {
+ PyObject *n, *result;
+ n = PyInt_FromLong(count);
+ if (n == NULL)
+ return NULL;
+ result = binary_op1(o, n, NB_SLOT(nb_multiply));
+ Py_DECREF(n);
+ if (result != Py_NotImplemented)
+ return result;
+ Py_DECREF(result);
+ }
return type_error("object can't be repeated");
}
@@ -1176,6 +1196,13 @@
if (m && m->sq_concat)
return m->sq_concat(s, o);
+ if (PySequence_Check(s) && PySequence_Check(o)) {
+ PyObject *result = binary_iop1(s, o, NB_SLOT(nb_inplace_add),
+ NB_SLOT(nb_add));
+ if (result != Py_NotImplemented)
+ return result;
+ Py_DECREF(result);
+ }
return type_error("object can't be concatenated");
}
@@ -1193,6 +1220,18 @@
if (m && m->sq_repeat)
return m->sq_repeat(o, count);
+ if (PySequence_Check(o)) {
+ PyObject *n, *result;
+ n = PyInt_FromLong(count);
+ if (n == NULL)
+ return NULL;
+ result = binary_iop1(o, n, NB_SLOT(nb_inplace_multiply),
+ NB_SLOT(nb_multiply));
+ Py_DECREF(n);
+ if (result != Py_NotImplemented)
+ return result;
+ Py_DECREF(result);
+ }
return type_error("object can't be repeated");
}
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 7c36ba4..b74fa1a 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -4095,9 +4095,6 @@
return len;
}
-SLOT1(slot_sq_concat, "__add__", PyObject *, "O")
-SLOT1(slot_sq_repeat, "__mul__", int, "i")
-
/* Super-optimized version of slot_sq_item.
Other slots could do the same... */
static PyObject *
@@ -4211,9 +4208,6 @@
return result;
}
-SLOT1(slot_sq_inplace_concat, "__iadd__", PyObject *, "O")
-SLOT1(slot_sq_inplace_repeat, "__imul__", int, "i")
-
#define slot_mp_length slot_sq_length
SLOT1(slot_mp_subscript, "__getitem__", PyObject *, "O")
@@ -4926,12 +4920,17 @@
static slotdef slotdefs[] = {
SQSLOT("__len__", sq_length, slot_sq_length, wrap_inquiry,
"x.__len__() <==> len(x)"),
- SQSLOT("__add__", sq_concat, slot_sq_concat, wrap_binaryfunc,
- "x.__add__(y) <==> x+y"),
- SQSLOT("__mul__", sq_repeat, slot_sq_repeat, wrap_intargfunc,
- "x.__mul__(n) <==> x*n"),
- SQSLOT("__rmul__", sq_repeat, slot_sq_repeat, wrap_intargfunc,
- "x.__rmul__(n) <==> n*x"),
+ /* Heap types defining __add__/__mul__ have sq_concat/sq_repeat == NULL.
+ The logic in abstract.c always falls back to nb_add/nb_multiply in
+ this case. Defining both the nb_* and the sq_* slots to call the
+ user-defined methods has unexpected side-effects, as shown by
+ test_descr.notimplemented() */
+ SQSLOT("__add__", sq_concat, NULL, wrap_binaryfunc,
+ "x.__add__(y) <==> x+y"),
+ SQSLOT("__mul__", sq_repeat, NULL, wrap_intargfunc,
+ "x.__mul__(n) <==> x*n"),
+ SQSLOT("__rmul__", sq_repeat, NULL, wrap_intargfunc,
+ "x.__rmul__(n) <==> n*x"),
SQSLOT("__getitem__", sq_item, slot_sq_item, wrap_sq_item,
"x.__getitem__(y) <==> x[y]"),
SQSLOT("__getslice__", sq_slice, slot_sq_slice, wrap_intintargfunc,
@@ -4953,10 +4952,10 @@
Use of negative indices is not supported."),
SQSLOT("__contains__", sq_contains, slot_sq_contains, wrap_objobjproc,
"x.__contains__(y) <==> y in x"),
- SQSLOT("__iadd__", sq_inplace_concat, slot_sq_inplace_concat,
- wrap_binaryfunc, "x.__iadd__(y) <==> x+=y"),
- SQSLOT("__imul__", sq_inplace_repeat, slot_sq_inplace_repeat,
- wrap_intargfunc, "x.__imul__(y) <==> x*=y"),
+ SQSLOT("__iadd__", sq_inplace_concat, NULL,
+ wrap_binaryfunc, "x.__iadd__(y) <==> x+=y"),
+ SQSLOT("__imul__", sq_inplace_repeat, NULL,
+ wrap_intargfunc, "x.__imul__(y) <==> x*=y"),
MPSLOT("__len__", mp_length, slot_mp_length, wrap_inquiry,
"x.__len__() <==> len(x)"),