bpo-35504: Fix a SystemError when delete the characters_written attribute of an OSError. (GH-11172)
diff --git a/Lib/test/test_exception_hierarchy.py b/Lib/test/test_exception_hierarchy.py
index 8649596..43b4af8 100644
--- a/Lib/test/test_exception_hierarchy.py
+++ b/Lib/test/test_exception_hierarchy.py
@@ -150,10 +150,15 @@
e = BlockingIOError(*args[:n])
with self.assertRaises(AttributeError):
e.characters_written
+ with self.assertRaises(AttributeError):
+ del e.characters_written
e = BlockingIOError("a", "b", 3)
self.assertEqual(e.characters_written, 3)
e.characters_written = 5
self.assertEqual(e.characters_written, 5)
+ del e.characters_written
+ with self.assertRaises(AttributeError):
+ e.characters_written
class ExplicitSubclassingTest(unittest.TestCase):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-12-15-00-47-41.bpo-35504.9gVuen.rst b/Misc/NEWS.d/next/Core and Builtins/2018-12-15-00-47-41.bpo-35504.9gVuen.rst
new file mode 100644
index 0000000..622b50c
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-12-15-00-47-41.bpo-35504.9gVuen.rst
@@ -0,0 +1 @@
+Fixed a SystemError when delete the characters_written attribute of an OSError.
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 05578d4..002a602 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -1196,6 +1196,14 @@
static int
OSError_written_set(PyOSErrorObject *self, PyObject *arg, void *context)
{
+ if (arg == NULL) {
+ if (self->written == -1) {
+ PyErr_SetString(PyExc_AttributeError, "characters_written");
+ return -1;
+ }
+ self->written = -1;
+ return 0;
+ }
Py_ssize_t n;
n = PyNumber_AsSsize_t(arg, PyExc_ValueError);
if (n == -1 && PyErr_Occurred())