python-checkins at python
May 7, 2012, 4:08 AM
Post #1 of 1
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cpython: Issue #14716: Change integer overflow check in unicode writer prepare()
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http://hg.python.org/cpython/rev/ab500b297900
changeset: 76821:ab500b297900
user: Victor Stinner <victor.stinner [at] gmail>
date: Mon May 07 13:02:44 2012 +0200
summary:
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, 4 insertions(+), 2 deletions(-)
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -13242,8 +13242,10 @@
newlen = writer->pos + length;
if (newlen > PyUnicode_GET_LENGTH(writer->buffer)) {
- /* overallocate 25% to limit the number of resize */
- if (newlen <= (PY_SSIZE_T_MAX - newlen / 4))
+ /* 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))
newlen += newlen / 4;
if (maxchar > writer->maxchar) {
--
Repository URL: http://hg.python.org/cpython
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