Do not let overflows in enumerate() and count() pass silently.

diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index 5e375c9b526d1067a4ee1d5191f628b974194d6c..c965d4c14efc3c126dbc71008069fa1bf7f49345 100644 (file)
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -52,8 +52,7 @@ class TestBasicOps(unittest.TestCase):
         self.assertEqual(take(2, zip('abc',count(3))), [('a', 3), ('b', 4)])
         self.assertRaises(TypeError, count, 2, 3)
         self.assertRaises(TypeError, count, 'a')
-        c = count(sys.maxint-2)   # verify that rollover doesn't crash
-        c.next(); c.next(); c.next(); c.next(); c.next()
+        self.assertRaises(OverflowError, list, islice(count(sys.maxint-5), 10))
         c = count(3)
         self.assertEqual(repr(c), 'count(3)')
         c.next()

diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 7896143b084f3d081e0e43c371f8767b7c2dbad0..70f787f784b2b6660bab88e5d79bb51027a4fbe7 100644 (file)
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -2073,6 +2073,11 @@ count_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 static PyObject *
 count_next(countobject *lz)
 {
+        if (lz->cnt == LONG_MAX) {
+                PyErr_SetString(PyExc_OverflowError,
+                        "cannot count beyond LONG_MAX");                
+                return NULL;         
+        }
        return PyInt_FromSsize_t(lz->cnt++);
 }
 

diff --git a/Objects/enumobject.c b/Objects/enumobject.c
index a8f43e07386b8464c4fe0f7b5ee9bfe75b2da056..a456c9dafd704e436b2943a8ab44e4f9f9ef5755 100644 (file)
--- a/Objects/enumobject.c
+++ b/Objects/enumobject.c
@@ -62,6 +62,12 @@ enum_next(enumobject *en)
        PyObject *result = en->en_result;
        PyObject *it = en->en_sit;
 
+       if (en->en_index == LONG_MAX) {
+               PyErr_SetString(PyExc_OverflowError,
+                       "enumerate() is limited to LONG_MAX items");                
+               return NULL;         
+       }
+
        next_item = (*it->ob_type->tp_iternext)(it);
        if (next_item == NULL)
                return NULL;