bpo-42248: [Enum] ensure exceptions raised in ``_missing_`` are released (GH-25350)
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 6002cd8..5af7cd2 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -1932,6 +1932,38 @@ def _missing_(cls, item):
else:
raise Exception('Exception not raised.')
+ def test_missing_exceptions_reset(self):
+ import weakref
+ #
+ class TestEnum(enum.Enum):
+ VAL1 = 'val1'
+ VAL2 = 'val2'
+ #
+ class Class1:
+ def __init__(self):
+ # Gracefully handle an exception of our own making
+ try:
+ raise ValueError()
+ except ValueError:
+ pass
+ #
+ class Class2:
+ def __init__(self):
+ # Gracefully handle an exception of Enum's making
+ try:
+ TestEnum('invalid_value')
+ except ValueError:
+ pass
+ # No strong refs here so these are free to die.
+ class_1_ref = weakref.ref(Class1())
+ class_2_ref = weakref.ref(Class2())
+ #
+ # The exception raised by Enum creates a reference loop and thus
+ # Class2 instances will stick around until the next gargage collection
+ # cycle, unlike Class1.
+ self.assertIs(class_1_ref(), None)
+ self.assertIs(class_2_ref(), None)
+
def test_multiple_mixin(self):
class MaxMixin:
@classproperty