libc: Fix mktime returns an uncorrect time in empty TZ case

The mktime API returned an uncorrect time when TZ is set as empty.
A timezone UTC/GMT+0 should be implied in the empty case. However
mktime keeps previous information about timezone. If mktime was called
with a timezone which has DST before, the "defaulttype" member of
"state" structure wouldn't be 0. Then it would be used next time,
even though UTC/GMT+0 doesn't have DST.

Added initialization of the "defaulttype" in the empty TZ case.

Change-Id: Ic480c63c548c05444134e0aefb30a7b380e3f40b
This commit is contained in:
Satoru Takeuchi 2014-05-27 17:04:04 +09:00 committed by Elliott Hughes
parent 38569312bc
commit 154e2026c8
2 changed files with 25 additions and 0 deletions

View File

@ -1257,6 +1257,7 @@ tzset_locked(void)
lclptr->ttis[0].tt_gmtoff = 0;
lclptr->ttis[0].tt_abbrind = 0;
(void) strcpy(lclptr->chars, gmt);
lclptr->defaulttype = 0;
} else if (tzload(name, lclptr, TRUE) != 0)
if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
(void) gmtload(lclptr);

View File

@ -71,6 +71,30 @@ TEST(time, gmtime_no_stack_overflow_14313703) {
ASSERT_EQ(0, pthread_join(t, &result));
}
TEST(time, mktime_empty_TZ) {
// tzcode used to have a bug where it didn't reinitialize some internal state.
// Choose a time where DST is set.
struct tm t;
memset(&t, 0, sizeof(tm));
t.tm_year = 1980 - 1900;
t.tm_mon = 6;
t.tm_mday = 2;
setenv("TZ", "America/Los_Angeles", 1);
tzset();
ASSERT_EQ(static_cast<time_t>(331372800U), mktime(&t));
memset(&t, 0, sizeof(tm));
t.tm_year = 1980 - 1900;
t.tm_mon = 6;
t.tm_mday = 2;
setenv("TZ", "", 1); // Implies UTC.
tzset();
ASSERT_EQ(static_cast<time_t>(331344000U), mktime(&t));
}
TEST(time, mktime_10310929) {
struct tm t;
memset(&t, 0, sizeof(tm));