Issue #22423: Unhandled exception in thread no longer causes unhandled
AttributeError when sys.stderr is None.
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 86c953f..ac41f2d 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -829,6 +829,85 @@
thread.start()
self.assertRaises(RuntimeError, setattr, thread, "daemon", True)
+ def test_print_exception(self):
+ script = r"""if 1:
+ import threading
+ import time
+
+ running = False
+ def run():
+ global running
+ running = True
+ while running:
+ time.sleep(0.01)
+ 1/0
+ t = threading.Thread(target=run)
+ t.start()
+ while not running:
+ time.sleep(0.01)
+ running = False
+ t.join()
+ """
+ rc, out, err = assert_python_ok("-c", script)
+ self.assertEqual(out, '')
+ self.assertIn("Exception in thread", err)
+ self.assertIn("Traceback (most recent call last):", err)
+ self.assertIn("ZeroDivisionError", err)
+ self.assertNotIn("Unhandled exception", err)
+
+ def test_print_exception_stderr_is_none_1(self):
+ script = r"""if 1:
+ import sys
+ import threading
+ import time
+
+ running = False
+ def run():
+ global running
+ running = True
+ while running:
+ time.sleep(0.01)
+ 1/0
+ t = threading.Thread(target=run)
+ t.start()
+ while not running:
+ time.sleep(0.01)
+ sys.stderr = None
+ running = False
+ t.join()
+ """
+ rc, out, err = assert_python_ok("-c", script)
+ self.assertEqual(out, '')
+ self.assertIn("Exception in thread", err)
+ self.assertIn("Traceback (most recent call last):", err)
+ self.assertIn("ZeroDivisionError", err)
+ self.assertNotIn("Unhandled exception", err)
+
+ def test_print_exception_stderr_is_none_2(self):
+ script = r"""if 1:
+ import sys
+ import threading
+ import time
+
+ running = False
+ def run():
+ global running
+ running = True
+ while running:
+ time.sleep(0.01)
+ 1/0
+ sys.stderr = None
+ t = threading.Thread(target=run)
+ t.start()
+ while not running:
+ time.sleep(0.01)
+ running = False
+ t.join()
+ """
+ rc, out, err = assert_python_ok("-c", script)
+ self.assertEqual(out, '')
+ self.assertNotIn("Unhandled exception", err)
+
class LockTests(lock_tests.LockTests):
locktype = staticmethod(threading.Lock)
diff --git a/Lib/threading.py b/Lib/threading.py
index e81471b..0438e1f 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -818,10 +818,10 @@
# shutdown) use self.__stderr. Otherwise still use sys (as in
# _sys) in case sys.stderr was redefined since the creation of
# self.
- if _sys:
- _sys.stderr.write("Exception in thread %s:\n%s\n" %
- (self.name, _format_exc()))
- else:
+ if _sys and _sys.stderr is not None:
+ print>>_sys.stderr, ("Exception in thread %s:\n%s" %
+ (self.name, _format_exc()))
+ elif self.__stderr is not None:
# Do the best job possible w/o a huge amt. of code to
# approximate a traceback (code ideas from
# Lib/traceback.py)