Test QDateTime behavior in DST gap

Historic QDateTime behavior when being asked to create a
QDateTime in the DST gap was to interpret the given date
as if it was in the time before that gap, mapping it to a point
in time after the gap. This has changed (after Qt 5.15) with
a04411119ead3d4473e4f0ac4bceedc585977b2f .
Since then, the given date is interpreted as if it was in the
time after the gap, thus being mapped to a point in time
before the gap.
This was not caught (in dev) by Coin because machines ran in
timezone "Atlantic/Reykjavik" which does not have DST since 1967.
This patch changes tests to always run in "Europe/Oslo".
A support function and each test-case thus need to use zone-time
instead of local time.

Fixes: QTBUG-86960
Fixes: QTBUG-89208
Change-Id: Iecce5898bf9711a10e7dfc0a25e4bbeaed1c8ade
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 3d785249ba43cf4bd895ed679bac2791e0130dc5)
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 6 insertions, 1 deletions

diff --git a/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp b/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
index 4a0fc81a9c..3f0af84e4e 100644
--- a/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
+++ b/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
@@ -2705,6 +2705,9 @@ void tst_QDateTime::fromStringStringFormat()
 #endif
         // OffsetFromUTC needs an offset check - we may as well do it for all:
         QCOMPARE(dt.offsetFromUtc(), expected.offsetFromUtc());
+    } else {
+        QCOMPARE(dt.isValid(), expected.isValid());
+        QCOMPARE(dt.toMSecsSinceEpoch(), expected.toMSecsSinceEpoch());
     }
 }
 
@@ -3176,7 +3179,9 @@ void tst_QDateTime::daylightTransitions() const
         QDateTime missing(QDate(2012, 3, 25), QTime(2, 0, 0));
         QVERIFY(!missing.isValid());
         QCOMPARE(missing.date(), QDate(2012, 3, 25));
-        QCOMPARE(missing.time(), QTime(2, 0, 0));
+        QCOMPARE(missing.time(), QTime(2, 0));
+        // datetimeparser relies on toMSecsSinceEpoch to still work:
+        QCOMPARE(missing.toMSecsSinceEpoch(), daylight2012);
 
         QDateTime after(QDate(2012, 3, 25), QTime(3, 0, 0));
         QVERIFY(after.isValid());