diff options
| -rw-r--r-- | Lib/test/test_with.py | 30 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Python/ceval.c | 13 |
3 files changed, 44 insertions, 2 deletions
diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py index 43f3271..b192429 100644 --- a/Lib/test/test_with.py +++ b/Lib/test/test_with.py @@ -505,6 +505,36 @@ class ExceptionalTestCase(ContextmanagerAssertionMixin, unittest.TestCase): 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 __bool__(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): @@ -12,6 +12,9 @@ What's New in Python 3.1 alpha 0 Core and Builtins ----------------- +- Issue #4597: Fixed exception handling when the __exit__ function of a + context manager returns a value that cannot be converted to a bool. + - Issue #4445: Replace "sizeof(PyBytesObject)" with "offsetof(PyBytesObject, ob_sval) + 1" when allocating memory for bytes instances. On a typical machine this saves 3 bytes of memory diff --git a/Python/ceval.c b/Python/ceval.c index c394554..84d18b3 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -2189,7 +2189,17 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag) Py_DECREF(exit_func); if (x == NULL) break; /* Go to error exit */ - if (u != Py_None && PyObject_IsTrue(x)) { + + if (u != Py_None) + err = PyObject_IsTrue(x); + else + err = 0; + Py_DECREF(x); + + if (err < 0) + break; /* Go to error exit */ + else if (err > 0) { + err = 0; /* There was an exception and a True return */ STACKADJ(-2); SET_TOP(PyLong_FromLong((long) WHY_SILENCED)); @@ -2197,7 +2207,6 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag) Py_DECREF(v); Py_DECREF(w); } - Py_DECREF(x); PREDICT(END_FINALLY); break; } |