[Python-checkins] gh-95882: fix regression in the traceback of exceptions propagated from inside a contextlib context manager (#95883)
iritkatriel
webhook-mailer at python.org
Tue Jan 3 10:47:33 EST 2023
https://github.com/python/cpython/commit/b3722ca058f6a6d6505cf2ea9ffabaf7fb6b6e19
commit: b3722ca058f6a6d6505cf2ea9ffabaf7fb6b6e19
branch: main
author: Thomas Grainger <tagrain at gmail.com>
committer: iritkatriel <1055913+iritkatriel at users.noreply.github.com>
date: 2023-01-03T15:47:13Z
summary:
gh-95882: fix regression in the traceback of exceptions propagated from inside a contextlib context manager (#95883)
files:
A Misc/NEWS.d/next/Library/2022-08-11-10-02-19.gh-issue-95882.FsUr72.rst
M Lib/contextlib.py
M Lib/test/test_contextlib.py
M Lib/test/test_contextlib_async.py
M Misc/ACKS
diff --git a/Lib/contextlib.py b/Lib/contextlib.py
index d5822219b3e2..30d9ac25b2bb 100644
--- a/Lib/contextlib.py
+++ b/Lib/contextlib.py
@@ -173,7 +173,7 @@ def __exit__(self, typ, value, traceback):
isinstance(value, StopIteration)
and exc.__cause__ is value
):
- exc.__traceback__ = traceback
+ value.__traceback__ = traceback
return False
raise
except BaseException as exc:
@@ -228,6 +228,7 @@ async def __aexit__(self, typ, value, traceback):
except RuntimeError as exc:
# Don't re-raise the passed in exception. (issue27122)
if exc is value:
+ exc.__traceback__ = traceback
return False
# Avoid suppressing if a Stop(Async)Iteration exception
# was passed to athrow() and later wrapped into a RuntimeError
@@ -239,6 +240,7 @@ async def __aexit__(self, typ, value, traceback):
isinstance(value, (StopIteration, StopAsyncIteration))
and exc.__cause__ is value
):
+ value.__traceback__ = traceback
return False
raise
except BaseException as exc:
@@ -250,6 +252,7 @@ async def __aexit__(self, typ, value, traceback):
# and the __exit__() protocol.
if exc is not value:
raise
+ exc.__traceback__ = traceback
return False
raise RuntimeError("generator didn't stop after athrow()")
diff --git a/Lib/test/test_contextlib.py b/Lib/test/test_contextlib.py
index 31f5c74572b6..ec06785b5667 100644
--- a/Lib/test/test_contextlib.py
+++ b/Lib/test/test_contextlib.py
@@ -104,15 +104,39 @@ def f():
self.assertEqual(frames[0].line, '1/0')
# Repeat with RuntimeError (which goes through a different code path)
+ class RuntimeErrorSubclass(RuntimeError):
+ pass
+
try:
with f():
- raise NotImplementedError(42)
- except NotImplementedError as e:
+ raise RuntimeErrorSubclass(42)
+ except RuntimeErrorSubclass as e:
frames = traceback.extract_tb(e.__traceback__)
self.assertEqual(len(frames), 1)
self.assertEqual(frames[0].name, 'test_contextmanager_traceback')
- self.assertEqual(frames[0].line, 'raise NotImplementedError(42)')
+ self.assertEqual(frames[0].line, 'raise RuntimeErrorSubclass(42)')
+
+ class StopIterationSubclass(StopIteration):
+ pass
+
+ for stop_exc in (
+ StopIteration('spam'),
+ StopIterationSubclass('spam'),
+ ):
+ with self.subTest(type=type(stop_exc)):
+ try:
+ with f():
+ raise stop_exc
+ except type(stop_exc) as e:
+ self.assertIs(e, stop_exc)
+ frames = traceback.extract_tb(e.__traceback__)
+ else:
+ self.fail(f'{stop_exc} was suppressed')
+
+ self.assertEqual(len(frames), 1)
+ self.assertEqual(frames[0].name, 'test_contextmanager_traceback')
+ self.assertEqual(frames[0].line, 'raise stop_exc')
def test_contextmanager_no_reraise(self):
@contextmanager
diff --git a/Lib/test/test_contextlib_async.py b/Lib/test/test_contextlib_async.py
index b64673d2c31e..3d43ed0fcab1 100644
--- a/Lib/test/test_contextlib_async.py
+++ b/Lib/test/test_contextlib_async.py
@@ -5,6 +5,7 @@
import functools
from test import support
import unittest
+import traceback
from test.test_contextlib import TestBaseExitStack
@@ -125,6 +126,62 @@ async def woohoo():
raise ZeroDivisionError()
self.assertEqual(state, [1, 42, 999])
+ @_async_test
+ async def test_contextmanager_traceback(self):
+ @asynccontextmanager
+ async def f():
+ yield
+
+ try:
+ async with f():
+ 1/0
+ except ZeroDivisionError as e:
+ frames = traceback.extract_tb(e.__traceback__)
+
+ self.assertEqual(len(frames), 1)
+ self.assertEqual(frames[0].name, 'test_contextmanager_traceback')
+ self.assertEqual(frames[0].line, '1/0')
+
+ # Repeat with RuntimeError (which goes through a different code path)
+ class RuntimeErrorSubclass(RuntimeError):
+ pass
+
+ try:
+ async with f():
+ raise RuntimeErrorSubclass(42)
+ except RuntimeErrorSubclass as e:
+ frames = traceback.extract_tb(e.__traceback__)
+
+ self.assertEqual(len(frames), 1)
+ self.assertEqual(frames[0].name, 'test_contextmanager_traceback')
+ self.assertEqual(frames[0].line, 'raise RuntimeErrorSubclass(42)')
+
+ class StopIterationSubclass(StopIteration):
+ pass
+
+ class StopAsyncIterationSubclass(StopAsyncIteration):
+ pass
+
+ for stop_exc in (
+ StopIteration('spam'),
+ StopAsyncIteration('ham'),
+ StopIterationSubclass('spam'),
+ StopAsyncIterationSubclass('spam')
+ ):
+ with self.subTest(type=type(stop_exc)):
+ try:
+ async with f():
+ raise stop_exc
+ except type(stop_exc) as e:
+ self.assertIs(e, stop_exc)
+ frames = traceback.extract_tb(e.__traceback__)
+ else:
+ self.fail(f'{stop_exc} was suppressed')
+
+ self.assertEqual(len(frames), 1)
+ self.assertEqual(frames[0].name, 'test_contextmanager_traceback')
+ self.assertEqual(frames[0].line, 'raise stop_exc')
+
@_async_test
async def test_contextmanager_no_reraise(self):
@asynccontextmanager
diff --git a/Misc/ACKS b/Misc/ACKS
index d50cb3c2d1ee..b4e309c6905b 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -645,6 +645,7 @@ Hans de Graaff
Tim Graham
Kim Gräsman
Alex Grönholm
+Thomas Grainger
Nathaniel Gray
Eddy De Greef
Duane Griffin
diff --git a/Misc/NEWS.d/next/Library/2022-08-11-10-02-19.gh-issue-95882.FsUr72.rst b/Misc/NEWS.d/next/Library/2022-08-11-10-02-19.gh-issue-95882.FsUr72.rst
new file mode 100644
index 000000000000..9cdb237d5c87
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-08-11-10-02-19.gh-issue-95882.FsUr72.rst
@@ -0,0 +1 @@
+Fix a 3.11 regression in :func:`~contextlib.asynccontextmanager`, which caused it to propagate exceptions with incorrect tracebacks and fix a 3.11 regression in :func:`~contextlib.contextmanager`, which caused it to propagate exceptions with incorrect tracebacks for :exc:`StopIteration`.
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