QQmlGadgetPtrWrapper: Consider QVariant as possible type

If the type is QVariant, we have to store and retrieve the member as-is,
instead of wrapping and unwrapping it.

Pick-to: 6.7
Fixes: QTBUG-123484
Change-Id: I01ac33158236b0f1082744aafa86108225b68392
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

4 files changed, 79 insertions, 5 deletions

diff --git a/src/qml/qml/qqmlvaluetype.cpp b/src/qml/qml/qqmlvaluetype.cpp
index 428ce9b697..4088d6e6c4 100644
--- a/src/qml/qml/qqmlvaluetype.cpp
+++ b/src/qml/qml/qqmlvaluetype.cpp
@@ -55,16 +55,25 @@ void QQmlGadgetPtrWrapper::write(
 QVariant QQmlGadgetPtrWrapper::value() const
 {
     Q_ASSERT(m_gadgetPtr);
-    return QVariant(metaType(), m_gadgetPtr);
+
+    const QMetaType m = metaType();
+    return m == QMetaType::fromType<QVariant>()
+            ? *static_cast<const QVariant *>(m_gadgetPtr)
+            : QVariant(m, m_gadgetPtr);
 }
 
 void QQmlGadgetPtrWrapper::setValue(const QVariant &value)
 {
     Q_ASSERT(m_gadgetPtr);
-    Q_ASSERT(metaType() == value.metaType());
-    const QQmlValueType *type = valueType();
-    type->destruct(m_gadgetPtr);
-    type->construct(m_gadgetPtr, value.constData());
+
+    const QMetaType m = metaType();
+    m.destruct(m_gadgetPtr);
+    if (m == QMetaType::fromType<QVariant>()) {
+        m.construct(m_gadgetPtr, &value);
+    } else {
+        Q_ASSERT(m == value.metaType());
+        m.construct(m_gadgetPtr, value.constData());
+    }
 }
 
 int QQmlGadgetPtrWrapper::metaCall(QMetaObject::Call type, int id, void **argv)
diff --git a/tests/auto/quick/qquickdesignersupport/data/RegTestComponent.qml b/tests/auto/quick/qquickdesignersupport/data/RegTestComponent.qml
new file mode 100644
index 0000000000..8bb8480daf
--- /dev/null
+++ b/tests/auto/quick/qquickdesignersupport/data/RegTestComponent.qml
@@ -0,0 +1,20 @@
+import QtQuick 2.15
+import QtQuick.Controls 2.15
+
+QtObject {
+    id: root
+
+    property int currentCategory: 0
+
+
+
+    property var materialsNames: [[qsTr("Car Paint"), qsTr("Glittery Car Paint"), qsTr("Aluminium"), qsTr("Chrome"), qsTr("Steel"), qsTr("Brushed Steel"), qsTr("Steel Floor"), qsTr("Copper"), qsTr("Silver"), qsTr("Gold"), qsTr("Mirror")],
+                                  [qsTr("Asphalt"), qsTr("Brick"), qsTr("Ceramic"), qsTr("Concrete"), qsTr("Glass"), qsTr("Darkened Glass"), qsTr("Wood"), qsTr("Wood - Planks"), qsTr("Wood - Parquet"), qsTr("Stone")],
+                                  [qsTr("Acrylic Paint"), qsTr("Carbon Fiber"), qsTr("Shiny Plastic"), qsTr("Matte Plastic"), qsTr("Textured Plastic"), qsTr("Rubber"), qsTr("Wax")],
+                                  [qsTr("Fabric"), qsTr("Fabric: Rough"), qsTr("Fabric: Satin"), qsTr("Leather"), qsTr("Paper")]]
+
+
+
+   property var model: root.materialsNames[root.currentCategory]
+
+}
\ No newline at end of file
diff --git a/tests/auto/quick/qquickdesignersupport/data/regTestProperties.qml b/tests/auto/quick/qquickdesignersupport/data/regTestProperties.qml
new file mode 100644
index 0000000000..5ea3f58aff
--- /dev/null
+++ b/tests/auto/quick/qquickdesignersupport/data/regTestProperties.qml
@@ -0,0 +1,13 @@
+import QtQuick 2.11
+
+Rectangle {
+    objectName: "rootItem"
+    color: "white"
+    width: 800
+    height: 600
+
+    RegTestComponent {
+        objectName: "testComponent"
+
+    }
+}
diff --git a/tests/auto/quick/qquickdesignersupport/tst_qquickdesignersupport.cpp b/tests/auto/quick/qquickdesignersupport/tst_qquickdesignersupport.cpp
index 4a3c778938..bdc8f97d3a 100644
--- a/tests/auto/quick/qquickdesignersupport/tst_qquickdesignersupport.cpp
+++ b/tests/auto/quick/qquickdesignersupport/tst_qquickdesignersupport.cpp
@@ -42,6 +42,7 @@ private slots:
     void testDotProperties();
     void testItemReparenting();
     void testPropertyNames();
+    void regressionTestAllProperties();
 };
 
 
@@ -783,6 +784,37 @@ void tst_qquickdesignersupport::testPropertyNames()
     QVERIFY(!names.contains("testProperty"));
 }
 
+void tst_qquickdesignersupport::regressionTestAllProperties()
+{
+    QScopedPointer<QQuickView> view(new QQuickView);
+    view->engine()->setOutputWarningsToStandardError(false);
+    view->setSource(testFileUrl("regTestProperties.qml"));
+
+    QVERIFY(view->errors().isEmpty());
+    QQuickItem *rootItem = view->rootObject();
+    QVERIFY(rootItem);
+
+    QObject *component = rootItem->findChild<QObject*>("testComponent");
+
+    QVERIFY(component);
+    QCOMPARE(component->objectName(), QLatin1String("testComponent"));
+
+    QVERIFY(component);
+
+    QQuickDesignerSupport::PropertyNameList names
+            = QQuickDesignerSupportProperties::allPropertyNames(component);
+    QVERIFY(!names.isEmpty());
+
+    const QByteArrayList expectedNames = QByteArrayList {
+        "objectName", "currentCategory", "materialsNames", "model"
+    };
+
+    QCOMPARE(names, expectedNames);
+    names = QQuickDesignerSupportProperties::propertyNameListForWritableProperties(component);
+    QVERIFY(!names.isEmpty());
+    QCOMPARE(names, expectedNames);
+}
+
 QTEST_MAIN(tst_qquickdesignersupport)
 
 #include "tst_qquickdesignersupport.moc"