From fe4b1b4dc1a3e267733cf1523ba41852c1577f49 Mon Sep 17 00:00:00 2001
From: Irit Katriel <iritkatriel@yahoo.com>
Date: Tue, 23 Feb 2021 17:13:56 +0000
Subject: [PATCH 1/2] bpo-43146: fix None-handling in single-arg version of
 traceback.print_exception() and traceback.format_exception()

---
 Lib/test/test_traceback.py | 5 +++++
 Lib/traceback.py           | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
index 2261ea994209ff..5bd969d62493a4 100644
--- a/Lib/test/test_traceback.py
+++ b/Lib/test/test_traceback.py
@@ -234,6 +234,10 @@ def test_format_exception_only_exc(self):
 
     def test_exception_is_None(self):
         NONE_EXC_STRING = 'NoneType: None\n'
+        excfile = StringIO()
+        traceback.print_exception(None, file=excfile)
+        self.assertEqual(excfile.getvalue(), NONE_EXC_STRING)
+
         excfile = StringIO()
         traceback.print_exception(None, None, None, file=excfile)
         self.assertEqual(excfile.getvalue(), NONE_EXC_STRING)
@@ -243,6 +247,7 @@ def test_exception_is_None(self):
         self.assertEqual(excfile.getvalue(), NONE_EXC_STRING)
 
         self.assertEqual(traceback.format_exc(None), NONE_EXC_STRING)
+        self.assertEqual(traceback.format_exception(None), [NONE_EXC_STRING])
         self.assertEqual(
             traceback.format_exception(None, None, None), [NONE_EXC_STRING])
         self.assertEqual(
diff --git a/Lib/traceback.py b/Lib/traceback.py
index dfb296c5e7b177..8f908dd2e09444 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -91,7 +91,10 @@ def _parse_value_tb(exc, value, tb):
     if (value is _sentinel) != (tb is _sentinel):
         raise ValueError("Both or neither of value and tb must be given")
     if value is tb is _sentinel:
-        return exc, exc.__traceback__
+        if exc is not None:
+            return exc, exc.__traceback__
+        else:
+            return None, None
     return value, tb
 
 

From 1095d2f539ff50acc7d42ec70e13f257c3cd3026 Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Tue, 23 Feb 2021 17:20:17 +0000
Subject: [PATCH 2/2] =?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

---
 .../NEWS.d/next/Library/2021-02-23-17-20-16.bpo-43146.JAFplg.rst | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Library/2021-02-23-17-20-16.bpo-43146.JAFplg.rst

diff --git a/Misc/NEWS.d/next/Library/2021-02-23-17-20-16.bpo-43146.JAFplg.rst b/Misc/NEWS.d/next/Library/2021-02-23-17-20-16.bpo-43146.JAFplg.rst
new file mode 100644
index 00000000000000..151edbe28d246f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-02-23-17-20-16.bpo-43146.JAFplg.rst
@@ -0,0 +1 @@
+Handle None in single-arg versions of :func:`~traceback.print_exception` and :func:`~traceback.format_exception`.
\ No newline at end of file