[Python-checkins] cpython: Backout ab500b297900: the check for integer overflow is wrong

Mon May 7 23:50:12 CEST 2012

http://hg.python.org/cpython/rev/01581e8b50f2
changeset: 76829:01581e8b50f2
user: Victor Stinner <victor.stinner at gmail.com>
date: Mon May 07 23:50:05 2012 +0200
summary:
 Backout ab500b297900: the check for integer overflow is wrong
Issue #14716: Change integer overflow check in unicode_writer_prepare()
to compute the limit at compile time instead of runtime. Patch writen by Serhiy
Storchaka.
files:
 Objects/unicodeobject.c | 6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -13242,10 +13242,8 @@
 newlen = writer->pos + length;
 
 if (newlen > PyUnicode_GET_LENGTH(writer->buffer)) {
- /* Overallocate 25% to limit the number of resize.
- Check for integer overflow:
- (newlen + newlen / 4) <= PY_SSIZE_T_MAX */
- if (newlen <= (PY_SSIZE_T_MAX - PY_SSIZE_T_MAX / 5))
+ /* overallocate 25% to limit the number of resize */
+ if (newlen <= (PY_SSIZE_T_MAX - newlen / 4))
 newlen += newlen / 4;
 
 if (maxchar > writer->maxchar) {
-- 
Repository URL: http://hg.python.org/cpython
