From b6b8c1a7d299c076df3e1e07774f8d7070c974fd Mon Sep 17 00:00:00 2001
From: Brandt Bucher <brandtbucher@gmail.com>
Date: Wed, 26 Jun 2019 09:52:32 -0700
Subject: [PATCH 1/3] Add a test for error handling in bytearray.extend.

---
 Lib/test/test_builtin.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index b536cec064878f..61155799c44a92 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -1592,6 +1592,11 @@ 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)

From deb64d60e6cee8ff93545d230a6047dee4009f3b Mon Sep 17 00:00:00 2001
From: Brandt Bucher <brandtbucher@gmail.com>
Date: Wed, 26 Jun 2019 09:52:54 -0700
Subject: [PATCH 2/3] Fix error handling in bytearray.extend.

---
 Objects/bytearrayobject.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index c684db76736462..1bb19a9271b6c3 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -1698,6 +1698,10 @@ bytearray_extend(PyByteArrayObject *self, PyObject *iterable_of_ints)
     }
     Py_DECREF(bytearray_obj);
 
+    if (PyErr_Occurred()) {
+        return NULL;
+    }
+
     Py_RETURN_NONE;
 }
 

From 9c366ff91a143a7f846d87fb68eca8c36878820a Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Wed, 26 Jun 2019 18:41:04 +0000
Subject: [PATCH 3/3] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../Core and Builtins/2019-06-26-18-41-00.bpo-37417.VsZeHL.rst  | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2019-06-26-18-41-00.bpo-37417.VsZeHL.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-06-26-18-41-00.bpo-37417.VsZeHL.rst b/Misc/NEWS.d/next/Core and Builtins/2019-06-26-18-41-00.bpo-37417.VsZeHL.rst
new file mode 100644
index 00000000000000..f004631e236103
--- /dev/null
+++ b/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.
\ No newline at end of file