MonthGrid: fix dates being incorrect for certain timezonesHEADdev

When a QDate is passed to QML, it becomes to a JavaScript Date.
As Dates are stored in local time, the QDates we were passing to
QML had the potential to be one day off in certain timezones.
For example: 00:00 UTC converted to UTC-8 is 20:00 the day before.

Fix this by storing and providing dates as QDateTime so that we can
give it a time of day that can't possibly result in a different day
when converted to local time. It's fine to change the C++ API since
it's private, and nothing will change for the type that users see,
since they always get a Date.

Add a SystemEnvironment singleton to QQuickControlsTestUtils
(Qt.test.controls) to allow reading and writing environment
variables from QML.

Fixes: QTBUG-72208
Pick-to: 6.8 6.9 6.10
Change-Id: Idb4ab26568d8f1eddd5ab4cebe691e38173d02a9
Reviewed-by: Ulf Hermann <[email protected]>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/quickcontrolstestutils/controlstestutils.cpp b/src/quickcontrolstestutils/controlstestutils.cpp
index fb88d00d29..f6b02abbe3 100644
--- a/src/quickcontrolstestutils/controlstestutils.cpp
+++ b/src/quickcontrolstestutils/controlstestutils.cpp
@@ -186,6 +186,21 @@ QString QQuickControlsTestUtils::StyleInfo::styleName() const
     return QQuickStyle::name();
 }
 
+/*!
+    It's recommended to use try-finally (see tst_monthgrid.qml for an example)
+    or init/initTestCase and cleanup/cleanupTestCase if setting environment
+    variables, in order to restore previous values.
+*/
+QString QQuickControlsTestUtils::SystemEnvironment::value(const QString &name)
+{
+    return QString::fromLocal8Bit(qgetenv(name.toLocal8Bit()));
+}
+
+bool QQuickControlsTestUtils::SystemEnvironment::setValue(const QString &name, const QString &value)
+{
+    return qputenv(name.toLocal8Bit(), value.toLocal8Bit());
+}
+
 QString QQuickControlsTestUtils::visualFocusFailureMessage(QQuickControl *control)
 {
     QString message;