From 4c3a0a35cd80a0abb9628dc8d4ade911fe2d5015 Mon Sep 17 00:00:00 2001 From: Tim Peters Date: Mon, 10 Sep 2001 23:37:46 +0000 Subject: [PATCH] More on SF bug [#460020] bug or feature: unicode() and subclasses. tuple(i) repaired to return a true tuple when i is an instance of a tuple subclass. Added PyTuple_CheckExact macro. PySequence_Tuple(): if a tuple-like object isn't exactly a tuple, it's not safe to return the object as-is -- make a new tuple of it instead. --- Include/tupleobject.h | 1 + Lib/test/test_descr.py | 2 +- Objects/abstract.c | 6 +++++- 3 files changed, 7 insertions(+), 2 deletions(-) diff --git a/Include/tupleobject.h b/Include/tupleobject.h index 3da3fe0a49..c5ec1c2cec 100644 --- a/Include/tupleobject.h +++ b/Include/tupleobject.h @@ -27,6 +27,7 @@ typedef struct { extern DL_IMPORT(PyTypeObject) PyTuple_Type; #define PyTuple_Check(op) PyObject_TypeCheck(op, &PyTuple_Type) +#define PyTuple_CheckExact(op) ((op)->ob_type == &PyTuple_Type) extern DL_IMPORT(PyObject *) PyTuple_New(int size); extern DL_IMPORT(int) PyTuple_Size(PyObject *); diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py index 0bed6750ee..d756dc57d0 100644 --- a/Lib/test/test_descr.py +++ b/Lib/test/test_descr.py @@ -1416,7 +1416,7 @@ def inherits(): verify(v == t) a = madtuple((1,2,3,4,5)) verify(tuple(a) == (1,2,3,4,5)) - #XXX verify(tuple(a).__class__ is tuple) + verify(tuple(a).__class__ is tuple) a = madtuple(()) verify(tuple(a) == ()) #XXX verify(tuple(a).__class__ is tuple) diff --git a/Objects/abstract.c b/Objects/abstract.c index 37f7eeab05..3609948bee 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -1235,7 +1235,11 @@ PySequence_Tuple(PyObject *v) return null_error(); /* Special-case the common tuple and list cases, for efficiency. */ - if (PyTuple_Check(v)) { + if (PyTuple_CheckExact(v)) { + /* Note that we can't know whether it's safe to return + a tuple *subclass* instance as-is, hence the restriction + to exact tuples here. In contrasts, lists always make + a copy, so there's need for exactness below. */ Py_INCREF(v); return v; } -- 2.40.0