From: Tim Peters <tim.peters@gmail.com>
Date: Sat, 8 Jul 2000 02:26:47 +0000 (+0000)
Subject: The tail end of x_sub implicitly assumed that an unsigned short
X-Git-Tag: v2.0b1~1011
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=43f04a36cf4e809a8baa3a895268b527bfd6254c;p=thirdparty%2FPython%2Fcpython.git

The tail end of x_sub implicitly assumed that an unsigned short
contains 16 bits.  Not true on Cray J90.
---

diff --git a/Objects/longobject.c b/Objects/longobject.c
index df69a6da67ac..a28dbaf34d7f 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -1048,6 +1048,7 @@ x_sub(PyLongObject *a, PyLongObject *b)
 		borrow = a->ob_digit[i] - borrow;
 		z->ob_digit[i] = borrow & MASK;
 		borrow >>= SHIFT;
+		borrow &= 1; /* Keep only one sign bit */
 	}
 	assert(borrow == 0);
 	if (sign < 0)