wrapper: avoid undefined behaviour in macOS
0620b39b3b ("compat: add a mkstemps() compatibility function", 2009-05-31) included a function based on code from libiberty which would result in undefined behaviour in platforms where timeval's tv_usec is a 32-bit signed type as shown by: wrapper.c:505:31: runtime error: left shift of 594546 by 16 places cannot be represented in type '__darwin_suseconds_t' (aka 'int') interestingly the version of this code from gcc never had this bug and the code had a cast that would had prevented the issue (at least in 64-bit platforms) but was misapplied. change the cast to uint64_t so it also works in 32-bit platforms. Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Carlo Marcelo Arenas Belón committed
Jun 16, 2019 at 11:40 UTC
729a9b558b0408fdf60e39c96b04b33a333d8366
1 file changed
+1
-1
wrapper.c
+1
-1
@@ -502,7 +502,7 @@ int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
502
* Try TMP_MAX different filenames.
503
*/
504
gettimeofday(&tv, NULL);
505
- value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
505
+ value = ((uint64_t)tv.tv_usec << 16) ^ tv.tv_sec ^ getpid();
506
filename_template = &pattern[len - 6 - suffix_len];
507
for (count = 0; count < TMP_MAX; ++count) {
508
uint64_t v = value;