From 7e32903c3f0ad3a930388d7ca20c0281f186499a Mon Sep 17 00:00:00 2001 From: "raymond.hettinger" Date: Mon, 2 Feb 2009 21:50:13 +0000 Subject: [PATCH] Issue 1242657: list(obj) can swallow KeyboardInterrupt. git-svn-id: http://svn.python.org/projects/python/trunk@69227 6015fed2-1504-0410-9fe1-9d1591cc4771 --- Include/abstract.h | 2 +- Lib/test/test_iterlen.py | 31 +++++++++++++++++++++++++++++++ Misc/NEWS | 4 ++++ Objects/abstract.c | 33 +++++++++++++++++++-------------- Objects/bytearrayobject.c | 4 ++++ Objects/listobject.c | 4 ++++ Python/bltinmodule.c | 2 ++ 7 files changed, 65 insertions(+), 15 deletions(-) diff --git a/Include/abstract.h b/Include/abstract.h index 87afe9a640..fc9c6b5b45 100644 --- a/Include/abstract.h +++ b/Include/abstract.h @@ -438,7 +438,7 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/ /* Guess the size of object o using len(o) or o.__length_hint__(). If neither of those return a non-negative value, then return the - default value. This function never fails. All exceptions are cleared. + default value. If one of the calls fails, this function returns -1. */ PyAPI_FUNC(PyObject *) PyObject_GetItem(PyObject *o, PyObject *key); diff --git a/Lib/test/test_iterlen.py b/Lib/test/test_iterlen.py index 2a32512e8f..91873c2af4 100644 --- a/Lib/test/test_iterlen.py +++ b/Lib/test/test_iterlen.py @@ -195,6 +195,36 @@ class TestListReversed(TestInvariantWithoutMutations): d.extend(xrange(20)) self.assertEqual(len(it), 0) +## -- Check to make sure exceptions are not suppressed by __length_hint__() + + +class BadLen(object): + def __iter__(self): return iter(range(10)) + def __len__(self): + raise RuntimeError('hello') + +class BadLengthHint(object): + def __iter__(self): return iter(range(10)) + def __length_hint__(self): + raise RuntimeError('hello') + +class TestLengthHintExceptions(unittest.TestCase): + + def test_issue1242657(self): + self.assertRaises(RuntimeError, list, BadLen()) + self.assertRaises(RuntimeError, list, BadLengthHint()) + self.assertRaises(RuntimeError, [].extend, BadLen()) + self.assertRaises(RuntimeError, [].extend, BadLengthHint()) + self.assertRaises(RuntimeError, zip, BadLen()) + self.assertRaises(RuntimeError, zip, BadLengthHint()) + self.assertRaises(RuntimeError, filter, None, BadLen()) + self.assertRaises(RuntimeError, filter, None, BadLengthHint()) + self.assertRaises(RuntimeError, map, chr, BadLen()) + self.assertRaises(RuntimeError, map, chr, BadLengthHint()) + b = bytearray(range(10)) + self.assertRaises(RuntimeError, b.extend, BadLen()) + self.assertRaises(RuntimeError, b.extend, BadLengthHint()) + def test_main(): unittests = [ TestRepeat, @@ -209,6 +239,7 @@ def test_main(): TestSet, TestList, TestListReversed, + TestLengthHintExceptions, ] test_support.run_unittest(*unittests) diff --git a/Misc/NEWS b/Misc/NEWS index f399fde571..4954c8b6f5 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -14,6 +14,10 @@ Core and Builtins - Issue #4978: Passing keyword arguments as unicode strings is now allowed. +- Issue 1242657: the __len__() and __length_hint__() calls in several tools + were suppressing all exceptions. These include list(), filter(), map(), + zip(), and bytearray(). + - os.ftruncate raises OSErrors instead of IOErrors for consistency with other os functions. diff --git a/Objects/abstract.c b/Objects/abstract.c index 0d6aa4adb3..1ac4ac95b5 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -85,8 +85,8 @@ PyObject_Length(PyObject *o) /* The length hint function returns a non-negative value from o.__len__() or o.__length_hint__(). If those methods aren't found or return a negative - value, then the defaultvalue is returned. This function never fails. - Accordingly, it will mask exceptions raised in either method. + value, then the defaultvalue is returned. If one of the calls fails, + this function returns -1. */ Py_ssize_t @@ -100,29 +100,32 @@ _PyObject_LengthHint(PyObject *o, Py_ssize_t defaultvalue) rv = PyObject_Size(o); if (rv >= 0) return rv; - if (PyErr_Occurred()) + if (PyErr_Occurred()) { + if (!PyErr_ExceptionMatches(PyExc_TypeError) && + !PyErr_ExceptionMatches(PyExc_AttributeError)) + return -1; PyErr_Clear(); + } /* cache a hashed version of the attribute string */ if (hintstrobj == NULL) { hintstrobj = PyString_InternFromString("__length_hint__"); if (hintstrobj == NULL) - goto defaultcase; + return -1; } /* try o.__length_hint__() */ ro = PyObject_CallMethodObjArgs(o, hintstrobj, NULL); - if (ro == NULL) - goto defaultcase; + if (ro == NULL) { + if (!PyErr_ExceptionMatches(PyExc_TypeError) && + !PyErr_ExceptionMatches(PyExc_AttributeError)) + return -1; + PyErr_Clear(); + return defaultvalue; + } rv = PyInt_AsLong(ro); Py_DECREF(ro); - if (rv >= 0) - return rv; - -defaultcase: - if (PyErr_Occurred()) - PyErr_Clear(); - return defaultvalue; + return rv; } PyObject * @@ -2128,7 +2131,7 @@ PySequence_Tuple(PyObject *v) { PyObject *it; /* iter(v) */ Py_ssize_t n; /* guess for result tuple size */ - PyObject *result; + PyObject *result = NULL; Py_ssize_t j; if (v == NULL) @@ -2153,6 +2156,8 @@ PySequence_Tuple(PyObject *v) /* Guess result size and allocate space. */ n = _PyObject_LengthHint(v, 10); + if (n == -1) + goto Fail; result = PyTuple_New(n); if (result == NULL) goto Fail; diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c index 4b8d585c8b..4cfd9f839c 100644 --- a/Objects/bytearrayobject.c +++ b/Objects/bytearrayobject.c @@ -2691,6 +2691,10 @@ bytes_extend(PyByteArrayObject *self, PyObject *arg) /* Try to determine the length of the argument. 32 is abitrary. */ buf_size = _PyObject_LengthHint(arg, 32); + if (buf_size == -1) { + Py_DECREF(it); + return NULL; + } bytes_obj = PyByteArray_FromStringAndSize(NULL, buf_size); if (bytes_obj == NULL) diff --git a/Objects/listobject.c b/Objects/listobject.c index 7b4bf35a3f..98d7e47354 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -838,6 +838,10 @@ listextend(PyListObject *self, PyObject *b) /* Guess a result list size. */ n = _PyObject_LengthHint(b, 8); + if (n == -1) { + Py_DECREF(it); + return NULL; + } m = Py_SIZE(self); mn = m + n; if (mn >= m) { diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c index 4e6f901ab3..4d7dec1c3f 100644 --- a/Python/bltinmodule.c +++ b/Python/bltinmodule.c @@ -268,6 +268,8 @@ builtin_filter(PyObject *self, PyObject *args) /* Guess a result list size. */ len = _PyObject_LengthHint(seq, 8); + if (len == -1) + goto Fail_it; /* Get a result list. */ if (PyList_Check(seq) && seq->ob_refcnt == 1) { -- 2.11.4.GIT