[Python-checkins] bpo-29843: raise AttributeError if given negative _length_ (GH-10029)

Mon Oct 22 15:22:17 EDT 2018

https://github.com/python/cpython/commit/2447773573e74819e163f8963ab107bc5db123e5
commit: 2447773573e74819e163f8963ab107bc5db123e5
branch: master
author: Tal Einat <taleinat+github at gmail.com>
committer: GitHub <noreply at github.com>
date: 2018年10月22日T18:33:10+03:00
summary:
bpo-29843: raise AttributeError if given negative _length_ (GH-10029)
Raise ValueError OverflowError in case of a negative
_length_ in a ctypes.Array subclass. Also raise TypeError
instead of AttributeError for non-integer _length_.
Co-authored-by: Oren Milman <orenmn at gmail.com>
files:
A Misc/NEWS.d/next/Core and Builtins/2018-10-21-17-43-48.bpo-29743.aeCcKR.rst
M Lib/ctypes/test/test_arrays.py
M Modules/_ctypes/_ctypes.c

diff --git a/Lib/ctypes/test/test_arrays.py b/Lib/ctypes/test/test_arrays.py
index 6e562cfd24e6..6cfda8b7d2e6 100644
--- a/Lib/ctypes/test/test_arrays.py
+++ b/Lib/ctypes/test/test_arrays.py
@@ -163,8 +163,6 @@ class Y(T):
 self.assertEqual(Y()._length_, 187)
 
 def test_bad_subclass(self):
- import sys
-
 with self.assertRaises(AttributeError):
 class T(Array):
 pass
@@ -174,14 +172,30 @@ class T(Array):
 with self.assertRaises(AttributeError):
 class T(Array):
 _length_ = 13
- with self.assertRaises(OverflowError):
+
+ def test_bad_length(self):
+ with self.assertRaises(ValueError):
 class T(Array):
 _type_ = c_int
- _length_ = sys.maxsize * 2
- with self.assertRaises(AttributeError):
+ _length_ = - sys.maxsize * 2
+ with self.assertRaises(ValueError):
+ class T(Array):
+ _type_ = c_int
+ _length_ = -1
+ with self.assertRaises(TypeError):
 class T(Array):
 _type_ = c_int
 _length_ = 1.87
+ with self.assertRaises(OverflowError):
+ class T(Array):
+ _type_ = c_int
+ _length_ = sys.maxsize * 2
+
+ def test_zero_length(self):
+ # _length_ can be zero.
+ class T(Array):
+ _type_ = c_int
+ _length_ = 0
 
 @unittest.skipUnless(sys.maxsize > 2**32, 'requires 64bit platform')
 @bigmemtest(size=_2G, memuse=1, dry_run=False)
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-10-21-17-43-48.bpo-29743.aeCcKR.rst b/Misc/NEWS.d/next/Core and Builtins/2018-10-21-17-43-48.bpo-29743.aeCcKR.rst
new file mode 100644
index 000000000000..9e79bb388e85
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-10-21-17-43-48.bpo-29743.aeCcKR.rst	
@@ -0,0 +1,4 @@
+Raise :exc:`ValueError` instead of :exc:`OverflowError` in case of a negative
+``_length_`` in a :class:`ctypes.Array` subclass. Also raise :exc:`TypeError`
+instead of :exc:`AttributeError` for non-integer ``_length_``.
+Original patch by Oren Milman.
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 3ae6348fef43..60f6985a6646 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -1405,13 +1405,28 @@ PyCArrayType_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 type_attr = NULL;
 
 length_attr = PyObject_GetAttrString((PyObject *)result, "_length_");
- if (!length_attr || !PyLong_Check(length_attr)) {
- PyErr_SetString(PyExc_AttributeError,
- "class must define a '_length_' attribute, "
- "which must be a positive integer");
- Py_XDECREF(length_attr);
+ if (!length_attr) {
+ if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
+ PyErr_SetString(PyExc_AttributeError,
+ "class must define a '_length_' attribute");
+ }
+ goto error;
+ }
+
+ if (!PyLong_Check(length_attr)) {
+ Py_DECREF(length_attr);
+ PyErr_SetString(PyExc_TypeError,
+ "The '_length_' attribute must be an integer");
 goto error;
 }
+
+ if (_PyLong_Sign(length_attr) == -1) {
+ Py_DECREF(length_attr);
+ PyErr_SetString(PyExc_ValueError,
+ "The '_length_' attribute must not be negative");
+ goto error;
+ }
+
 length = PyLong_AsSsize_t(length_attr);
 Py_DECREF(length_attr);
 if (length == -1 && PyErr_Occurred()) {
