Backported issue #4589 to Python 2.5.3: Propagated an exception thrown by a
context manager's __exit__ method's result while it's being converted to bool.
diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py
index 3ba8977..3004675 100644
--- a/Lib/test/test_with.py
+++ b/Lib/test/test_with.py
@@ -505,6 +505,36 @@
self.assertRaises(GeneratorExit, shouldThrow)
+ def testErrorsInBool(self):
+ # issue4589: __exit__ return code may raise an exception
+ # when looking at its truth value.
+
+ class cm(object):
+ def __init__(self, bool_conversion):
+ class Bool:
+ def __nonzero__(self):
+ return bool_conversion()
+ self.exit_result = Bool()
+ def __enter__(self):
+ return 3
+ def __exit__(self, a, b, c):
+ return self.exit_result
+
+ def trueAsBool():
+ with cm(lambda: True):
+ self.fail("Should NOT see this")
+ trueAsBool()
+
+ def falseAsBool():
+ with cm(lambda: False):
+ self.fail("Should raise")
+ self.assertRaises(AssertionError, falseAsBool)
+
+ def failAsBool():
+ with cm(lambda: 1//0):
+ self.fail("Should NOT see this")
+ self.assertRaises(ZeroDivisionError, failAsBool)
+
class NonLocalFlowControlTestCase(unittest.TestCase):