PySequence_Check(), PyMapping_Check(): only return true if the
corresponding "getitem" operation (sq_item or mp_subscript) is
implemented. I realize that "sequence-ness" and "mapping-ness" are
poorly defined (and the tests may still be wrong for user-defined
instances, which always have both slots filled), but I believe that a
sequence that doesn't support its getitem operation should not be
considered a sequence. All other operations are optional though.
For example, the ZODB BTree tests crashed because PySequence_Check()
returned true for a dictionary! (In 2.2, the dictionary type has a
tp_as_sequence pointer, but the only field filled is sq_contains, so
you can write "if key in dict".) With this fix, all standalone ZODB
tests succeed.
diff --git a/Objects/abstract.c b/Objects/abstract.c
index f7ade6d..c3a397c 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -919,7 +919,8 @@
int
PySequence_Check(PyObject *s)
{
- return s != NULL && s->ob_type->tp_as_sequence;
+ return s != NULL && s->ob_type->tp_as_sequence &&
+ s->ob_type->tp_as_sequence->sq_item != NULL;
}
int
@@ -1509,7 +1510,8 @@
int
PyMapping_Check(PyObject *o)
{
- return o && o->ob_type->tp_as_mapping;
+ return o && o->ob_type->tp_as_mapping &&
+ o->ob_type->tp_as_mapping->mp_subscript;
}
int