AC_DEFUN([gl_FUNC_TZSET_CLOBBER],
[
AC_REQUIRE([AC_HEADER_TIME])
AC_CACHE_CHECK([whether tzset clobbers localtime buffer],
gl_cv_func_tzset_clobber,
[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
int
main ()
{
time_t t1 = 853958121;
struct tm *p, s;
putenv ("TZ=GMT0");
p = localtime (&t1);
s = *p;
putenv ("TZ=EST+3EDT+2,M10.1.0/00:00:00,M2.3.0/00:00:00");
tzset ();
exit (p->tm_year != s.tm_year
|| p->tm_mon != s.tm_mon
|| p->tm_mday != s.tm_mday
|| p->tm_hour != s.tm_hour
|| p->tm_min != s.tm_min
|| p->tm_sec != s.tm_sec);
}
]])],
[gl_cv_func_tzset_clobber=no],
[gl_cv_func_tzset_clobber=yes],
[gl_cv_func_tzset_clobber=yes])])
AC_DEFINE(HAVE_RUN_TZSET_TEST, 1,
[Define to 1 if you have run the test for working tzset.])
if test $gl_cv_func_tzset_clobber = yes; then
gl_GETTIMEOFDAY_REPLACE_LOCALTIME
AC_DEFINE(tzset, rpl_tzset,
[Define to rpl_tzset if the wrapper function should be used.])
AC_DEFINE(TZSET_CLOBBERS_LOCALTIME_BUFFER, 1,
[Define if tzset clobbers localtime's static buffer.])
fi
])