Android: use BCP 47 tag to create a correct Locale for QTimeZone::displayName()

Before the patch we tried to create a java Locale object by passing the
human-readable language, territory and variant strings. However, the
Locale constructor accepts ISO-defined codes.

Fix it by using a factory method Locale.forLanguageTag() [0] that
constructs a Java Locale object based on BCP 47 tag.

[0]: https://developer.android.com/reference/java/util/Locale#forLanguageTag(java.lang.String)

Fixes: QTBUG-101460
Pick-to: 6.3 6.2 5.15
Change-Id: If414c66cf0e5b7e8299ffc3a6038b6f9eb79d5ec
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

1 files changed, 52 insertions, 0 deletions

diff --git a/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp b/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp
index f6d4f65346..0a18958fb6 100644
--- a/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp
+++ b/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp
@@ -75,6 +75,8 @@ private Q_SLOTS:
     void macTest();
     void darwinTypes();
     void winTest();
+    void localeSpecificDisplayName_data();
+    void localeSpecificDisplayName();
 
 private:
     void printTimeZone(const QTimeZone &tz);
@@ -1416,8 +1418,58 @@ void tst_QTimeZone::winTest()
     testEpochTranPrivate(QWinTimeZonePrivate("America/Toronto"));
 #endif // QT_BUILD_INTERNAL && USING_WIN_TZ
 }
+
 #undef ZONE_DNAME_CHECK
 
+void tst_QTimeZone::localeSpecificDisplayName_data()
+{
+#ifdef USING_WIN_TZ
+    QSKIP("MS backend does not use locale parameter");
+#endif
+    QTest::addColumn<QByteArray>("zoneName");
+    QTest::addColumn<QLocale>("locale");
+    QTest::addColumn<QTimeZone::TimeType>("timeType");
+    QTest::addColumn<QString>("expectedName");
+
+    QStringList names;
+    QLocale locale;
+    // Pick a non-system locale; German or French
+    if (QLocale::system().language() != QLocale::German) {
+        locale = QLocale(QLocale::German);
+        names << QString("Mitteleurop\u00e4ische Normalzeit")
+              << QString("Mitteleurop\u00e4ische Sommerzeit");
+    } else {
+        locale = QLocale(QLocale::French);
+        names << QString("heure normale d\u2019Europe centrale")
+              << QString("heure d\u2019\u00E9t\u00E9 d\u2019Europe centrale");
+    }
+
+    qsizetype index = 0;
+    QTest::newRow("Berlin, standard time")
+            << QByteArray("Europe/Berlin") << locale << QTimeZone::StandardTime
+            << names.at(index++);
+
+    QTest::newRow("Berlin, summer time")
+            << QByteArray("Europe/Berlin") << locale << QTimeZone::DaylightTime
+            << names.at(index++);
+}
+
+void tst_QTimeZone::localeSpecificDisplayName()
+{
+    // This test checks that QTimeZone::displayName() correctly uses the
+    // specified locale, NOT the system locale (see QTBUG-101460).
+    QFETCH(QByteArray, zoneName);
+    QFETCH(QLocale, locale);
+    QFETCH(QTimeZone::TimeType, timeType);
+    QFETCH(QString, expectedName);
+
+    QTimeZone zone(zoneName);
+    QVERIFY(zone.isValid());
+
+    const QString localeName = zone.displayName(timeType, QTimeZone::LongName, locale);
+    QCOMPARE(localeName, expectedName);
+}
+
 #ifdef QT_BUILD_INTERNAL
 // Test each private produces the same basic results for CET
 void tst_QTimeZone::testCetPrivate(const QTimeZonePrivate &tzp)