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.
This commit is contained in:
Jeffrey Yasskin 2008-12-10 07:28:12 +00:00
parent 05e9c9dd97
commit 478a1aa537
3 changed files with 42 additions and 3 deletions

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@ -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):

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@ -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.

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@ -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);
}