whytofly
/
qt6-bb10
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Be fussier about setting tst_QDateTime's globals. 

Time zones change on the whim of politicians.  Consequently, we can
seem to be in CET/CEST or on UTC (because we tested sample dates when
our zone coincided) when we aren't (i.e. we're in a materially
different zone at the time probed by some particular test).  Make the
initialization of the globals that test this more robust against
governmental meddling and document the unfixable problem with Algeria:
a DST transition *on the epoch*.

Change-Id: I17c5c81d339b80af12f4ffab367e28052dd6c2fa
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
bb10
Edward Welbourne 2016-01-12 15:16:25 +01:00
parent 722df6e0a2
commit f7d9e34b96
1 changed files with 62 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp
View File

@ -171,21 +171,70 @@ Q_DECLARE_METATYPE(Qt::DateFormat)
tst_QDateTime::tst_QDateTime()
{
uint x1 = QDateTime(QDate(1990, 1, 1), QTime()).toTime_t();
uint x2 = QDateTime(QDate(1990, 6, 1), QTime()).toTime_t();
zoneIsCET = (x1 == 631148400 && x2 == 644191200);
/*
Due to some jurisdictions changing their zones and rules, it's possible
for a non-CET zone to accidentally match CET at a few tested moments but
be different a few years later or earlier. This would lead to tests
failing if run in the partially-aliasing zone (e.g. Algeria, Lybia). So
test thoroughly; ideally at every mid-winter or mid-summer in whose
half-year any test below assumes zoneIsCET means what it says. (Tests at
or near a DST transition implicate both of the half-years that meet
there.) Years outside the 1970--2038 range, however, are likely not
properly handled by the TZ-database; and QDateTime explicitly handles them
differently, so don't probe them here.
*/
const uint day = 24 * 3600; // in seconds
zoneIsCET = (QDateTime(QDate(2038, 1, 19), QTime(4, 14, 7)).toTime_t() == 0x7fffffff
// Entries a year apart robustly differ by multiples of day.
&& QDateTime(QDate(2015, 7, 1), QTime()).toTime_t() == 1435701600
&& QDateTime(QDate(2015, 1, 1), QTime()).toTime_t() == 1420066800
&& QDateTime(QDate(2013, 7, 1), QTime()).toTime_t() == 1372629600
&& QDateTime(QDate(2013, 1, 1), QTime()).toTime_t() == 1356994800
&& QDateTime(QDate(2012, 7, 1), QTime()).toTime_t() == 1341093600
&& QDateTime(QDate(2012, 1, 1), QTime()).toTime_t() == 1325372400
&& QDateTime(QDate(2008, 7, 1), QTime()).toTime_t() == 1214863200
&& QDateTime(QDate(2004, 1, 1), QTime()).toTime_t() == 1072911600
&& QDateTime(QDate(2000, 1, 1), QTime()).toTime_t() == 946681200
&& QDateTime(QDate(1990, 7, 1), QTime()).toTime_t() == 646783200
&& QDateTime(QDate(1990, 1, 1), QTime()).toTime_t() == 631148400
&& QDateTime(QDate(1979, 1, 1), QTime()).toTime_t() == 283993200
// .toTime_t() returns -1 for everything before this:
&& QDateTime(QDate(1970, 1, 1), QTime(1, 0, 0)).toTime_t() == 0);
// Use .toMSecsSinceEpoch() if you really need to test anything earlier.
QDateTime dt1 = QDateTime::fromTime_t(0);
QDateTime dt2 = QDateTime::fromTime_t(181 * 86400); // six months later, Jul 1
if (dt1.date().year() < 1970 || dt2.date().month() < 7) {
localTimeType = LocalTimeBehindUtc;
} else if (dt1.time().hour() > 0 || dt1.date().day() > 1) {
localTimeType = LocalTimeAheadOfUtc;
} else if (dt2.time().hour() > 0 || dt2.date().day() > 1) {
localTimeType = LocalTimeAheadOfUtc;
} else {
localTimeType = LocalTimeIsUtc;
/*
Again, rule changes can cause a TZ to look like UTC at some sample dates
but deviate at some date relevant to a test using localTimeType. These
tests mostly use years outside the 1970--2038 range for which TZ data is
credible, so we can't helpfully be exhaustive. So scan a sample of years'
starts and middles.
*/
const int sampled = 3;
// UTC starts of months in 2004, 2038 and 1970:
uint jans[sampled] = { 12418 * day, 24837 * day, 0 };
uint juls[sampled] = { 12600 * day, 25018 * day, 181 * day };
localTimeType = LocalTimeIsUtc;
for (int i = sampled; i-- > 0; ) {
QDateTime jan = QDateTime::fromTime_t(jans[i]);
QDateTime jul = QDateTime::fromTime_t(juls[i]);
if (jan.date().year() < 1970 || jul.date().month() < 7) {
localTimeType = LocalTimeBehindUtc;
break;
} else if (jan.time().hour() > 0 || jul.time().hour() > 0
|| jan.date().day() > 1 || jul.date().day() > 1) {
localTimeType = LocalTimeAheadOfUtc;
break;
}
}
/*
Even so, TZ=Africa/Algiers will fail fromMSecsSinceEpoch(-1) because it
switched from WET without DST (i.e. UTC) in the late 1960s to WET with DST
for all of 1970 - so they had a DST transition *on the epoch*. They've
since switched to CET with no DST, making life simple; but our tests for
mistakes around the epoch can't tell the difference between what Algeria
really did and the symptoms we can believe a bug might produce: there's
not much we can do about that, that wouldn't hide real bugs.
*/
}
void tst_QDateTime::initTestCase()