bpo-37417: Fix error handling in bytearray.extend. (GH-14407)

(cherry picked from commit 2a7d596) Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

Author: miss-islington

Lib/test/test_builtin.py

@@ -1511,6 +1511,11 @@ def test_bytearray_translate(self):
  self.assertRaises(ValueError, x.translate, b"1", 1)
  self.assertRaises(TypeError, x.translate, b"1"*256, 1)
 
+ def test_bytearray_extend_error(self):
+ array = bytearray()
+ bad_iter = map(int, "X")
+ self.assertRaises(ValueError, array.extend, bad_iter)
+
  def test_construct_singletons(self):
  for const in None, Ellipsis, NotImplemented:
  tp = type(const)

Misc/NEWS.d/next/Core and Builtins/2019-06-26-18-41-00.bpo-37417.VsZeHL.rst

@@ -0,0 +1,2 @@
+:meth:`bytearray.extend` now correctly handles errors that arise during iteration.
+Patch by Brandt Bucher.

Objects/bytearrayobject.c

@@ -1689,6 +1689,10 @@ bytearray_extend(PyByteArrayObject *self, PyObject *iterable_of_ints)
  }
  Py_DECREF(bytearray_obj);
 
+ if (PyErr_Occurred()) {
+ return NULL;
+ }
+
  Py_RETURN_NONE;
 }