From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Tue, 19 Sep 2017 14:00:44 +0000 (-0700)
Subject: [3.6] bpo-31293: Fix crashes in truediv and mul of a timedelta by a float with a... 
X-Git-Tag: v3.6.4rc1~247
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f37dd11f0d4832c15d49c2ddc83d533ddaa36e74;p=python

[3.6] bpo-31293: Fix crashes in truediv and mul of a timedelta by a float with a bad as_integer_ratio() method. (GH-3227) (#3654)

(cherry picked from commit 865e4b4f630e2ae91e61239258abb58b488f1d65)
---

diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index b25e6c1713..77df1b3744 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -846,6 +846,26 @@ class TestTimeDelta(HarmlessMixedComparison, unittest.TestCase):
 
         self.assertRaises(TypeError, divmod, t, 10)
 
+    def test_issue31293(self):
+        # The interpreter shouldn't crash in case a timedelta is divided or
+        # multiplied by a float with a bad as_integer_ratio() method.
+        def get_bad_float(bad_ratio):
+            class BadFloat(float):
+                def as_integer_ratio(self):
+                    return bad_ratio
+            return BadFloat()
+
+        with self.assertRaises(TypeError):
+            timedelta() / get_bad_float(1 << 1000)
+        with self.assertRaises(TypeError):
+            timedelta() * get_bad_float(1 << 1000)
+
+        for bad_ratio in [(), (42, ), (1, 2, 3)]:
+            with self.assertRaises(ValueError):
+                timedelta() / get_bad_float(bad_ratio)
+            with self.assertRaises(ValueError):
+                timedelta() * get_bad_float(bad_ratio)
+
 
 #############################################################################
 # date tests
diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-08-28-17-51-42.bpo-31293.eMYZXj.rst b/Misc/NEWS.d/next/Core and Builtins/2017-08-28-17-51-42.bpo-31293.eMYZXj.rst
new file mode 100644
index 0000000000..28b7bfb2ef
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2017-08-28-17-51-42.bpo-31293.eMYZXj.rst	
@@ -0,0 +1,2 @@
+Fix crashes in true division and multiplication of a timedelta object by a
+float with a bad as_integer_ratio() method. Patch by Oren Milman.
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index c2ad9a203e..d44bb3e047 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -1646,6 +1646,33 @@ multiply_int_timedelta(PyObject *intobj, PyDateTime_Delta *delta)
     return result;
 }
 
+static PyObject *
+get_float_as_integer_ratio(PyObject *floatobj)
+{
+    PyObject *ratio;
+
+    assert(floatobj && PyFloat_Check(floatobj));
+    ratio = _PyObject_CallMethodId(floatobj, &PyId_as_integer_ratio, NULL);
+    if (ratio == NULL) {
+        return NULL;
+    }
+    if (!PyTuple_Check(ratio)) {
+        PyErr_Format(PyExc_TypeError,
+                     "unexpected return type from as_integer_ratio(): "
+                     "expected tuple, got '%.200s'",
+                     Py_TYPE(ratio)->tp_name);
+        Py_DECREF(ratio);
+        return NULL;
+    }
+    if (PyTuple_Size(ratio) != 2) {
+        PyErr_SetString(PyExc_ValueError,
+                        "as_integer_ratio() must return a 2-tuple");
+        Py_DECREF(ratio);
+        return NULL;
+    }
+    return ratio;
+}
+
 static PyObject *
 multiply_float_timedelta(PyObject *floatobj, PyDateTime_Delta *delta)
 {
@@ -1656,9 +1683,10 @@ multiply_float_timedelta(PyObject *floatobj, PyDateTime_Delta *delta)
     pyus_in = delta_to_microseconds(delta);
     if (pyus_in == NULL)
         return NULL;
-    ratio = _PyObject_CallMethodId(floatobj, &PyId_as_integer_ratio, NULL);
-    if (ratio == NULL)
+    ratio = get_float_as_integer_ratio(floatobj);
+    if (ratio == NULL) {
         goto error;
+    }
     temp = PyNumber_Multiply(pyus_in, PyTuple_GET_ITEM(ratio, 0));
     Py_DECREF(pyus_in);
     pyus_in = NULL;
@@ -1754,9 +1782,10 @@ truedivide_timedelta_float(PyDateTime_Delta *delta, PyObject *f)
     pyus_in = delta_to_microseconds(delta);
     if (pyus_in == NULL)
         return NULL;
-    ratio = _PyObject_CallMethodId(f, &PyId_as_integer_ratio, NULL);
-    if (ratio == NULL)
+    ratio = get_float_as_integer_ratio(f);
+    if (ratio == NULL) {
         goto error;
+    }
     temp = PyNumber_Multiply(pyus_in, PyTuple_GET_ITEM(ratio, 1));
     Py_DECREF(pyus_in);
     pyus_in = NULL;