From: Alexey Izbyshev <izbyshev@ispras.ru>
Date: Fri, 24 Aug 2018 04:39:45 +0000 (+0300)
Subject: closes bpo-34468: Objects/rangeobject.c: Fix an always-false condition in range_repr... 
X-Git-Tag: v3.8.0a1~1171
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ecae3ca0bda3cacf3b0125bae0bc718a17cc071;p=thirdparty%2FPython%2Fcpython.git

closes bpo-34468: Objects/rangeobject.c: Fix an always-false condition in range_repr() (GH-8880)

Also, propagate the error from PyNumber_AsSsize_t() because we don't care
only about OverflowError which is not reported if the second argument is NULL.

Reported by Svace static analyzer.
---

diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
index 28a244e53710..2b00a17425a2 100644
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -575,11 +575,11 @@ range_repr(rangeobject *r)
     Py_ssize_t istep;
 
     /* Check for special case values for printing.  We don't always
-       need the step value.  We don't care about errors
-       (it means overflow), so clear the errors. */
+       need the step value.  We don't care about overflow. */
     istep = PyNumber_AsSsize_t(r->step, NULL);
-    if (istep != 1 || (istep == -1 && PyErr_Occurred())) {
-        PyErr_Clear();
+    if (istep == -1 && PyErr_Occurred()) {
+        assert(!PyErr_ExceptionMatches(PyExc_OverflowError));
+        return NULL;
     }
 
     if (istep == 1)