From b96172e2cfbbd047959cb8b2a5b84b0b32388842 Mon Sep 17 00:00:00 2001
From: Mark Dickinson <mdickinson@enthought.com>
Date: Sat, 19 Nov 2011 17:58:15 +0000
Subject: [PATCH] Issue #9530: Fix undefined behaviour due to signed overflow
 in testcapi_long.h.

---
 Modules/testcapi_long.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Modules/testcapi_long.h b/Modules/testcapi_long.h
index 5784452edfc..6bddad7bb5d 100644
--- a/Modules/testcapi_long.h
+++ b/Modules/testcapi_long.h
@@ -33,8 +33,7 @@ TESTNAME(PyObject *error(const char*))
             unsigned TYPENAME uin, uout;
 
             /* For 0, 1, 2 use base; for 3, 4, 5 use -base */
-            uin = j < 3 ? base
-                        : (unsigned TYPENAME)(-(TYPENAME)base);
+            uin = j < 3 ? base : 0U - base;
 
             /* For 0 & 3, subtract 1.
              * For 1 & 4, leave alone.