diff options
| -rw-r--r-- | Lib/test/test_with.py | 30 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Python/ceval.c | 12 |
3 files changed, 42 insertions, 3 deletions
diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py index 3ba897798b..3004675414 100644 --- a/Lib/test/test_with.py +++ b/Lib/test/test_with.py @@ -505,6 +505,36 @@ class ExceptionalTestCase(unittest.TestCase, ContextmanagerAssertionMixin): 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): @@ -12,6 +12,9 @@ What's New in Python 2.5.3? Core and builtins ----------------- +- Issue #4589: Propagated an exception thrown by a context manager's + __exit__ method's result while it's being converted to bool. + - Issue #4317: Fixed a crash in the imageop.rgb2rgb8() function. - Issue #4230: If ``__getattr__`` is a descriptor, it now functions correctly. diff --git a/Python/ceval.c b/Python/ceval.c index ddfe3c48ea..d74149c4a9 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -2263,9 +2263,16 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag) x = PyObject_CallFunctionObjArgs(x, u, v, w, NULL); 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 */ - Py_DECREF(x); x = TOP(); /* Again */ STACKADJ(-3); Py_INCREF(Py_None); @@ -2276,7 +2283,6 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag) Py_DECREF(w); } else { /* Let END_FINALLY do its thing */ - Py_DECREF(x); x = POP(); Py_DECREF(x); } |