Merged revisions 67688 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r67688 | amaury.forgeotdarc | 2008-12-11 00:22:49 +0100 (jeu., 11 déc. 2008) | 6 lines
#4559: When a context manager's __exit__() method returns an object whose
conversion to bool raises an exception, 'with' loses that exception.
Reviewed by Jeffrey Yasskin.
Already ported to 2.5, will port to 2.6 and 3.0
........
diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py
index 3007e5a..bfeb06b 100644
--- a/Lib/test/test_with.py
+++ b/Lib/test/test_with.py
@@ -503,6 +503,36 @@
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):
diff --git a/Misc/NEWS b/Misc/NEWS
index effcf20..f1bc34f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
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 #4233: Changed semantic of ``_fileio.FileIO``'s ``close()``
method on file objects with closefd=False. The file descriptor is still
kept open but the file object behaves like a closed file. The ``FileIO``
diff --git a/Python/ceval.c b/Python/ceval.c
index 6eef7ef..dd1e171 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -2337,11 +2337,20 @@
/* XXX Not the fastest way to call it... */
x = PyObject_CallFunctionObjArgs(exit_func, u, v, w,
NULL);
- if (x == NULL) {
- Py_DECREF(exit_func);
+ 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);
Py_INCREF(Py_None);
@@ -2353,8 +2362,6 @@
/* The stack was rearranged to remove EXIT
above. Let END_FINALLY do its thing */
}
- Py_DECREF(x);
- Py_DECREF(exit_func);
PREDICT(END_FINALLY);
break;
}