QObjectWrapper: Use metaTypeFromJS for call arguments

We want the precise type there, not some approximation that happens to
be a QVariant. This exposes that we had a few conversions that were
possible with QVariant::convert() but not with our builtin type
coercion.

Pick-to: 6.5 6.6
Change-Id: I44c57a22bad8268de3d4398721e1c63b18009dfc
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/qml/jsruntime/qv4qobjectwrapper.cpp

@@ -2192,37 +2192,10 @@ bool CallArgument::fromValue(QMetaType metaType, ExecutionEngine *engine, const
     }
 
     // Convert via QVariant through the QML engine.
-    qvariantPtr = new (&allocData) QVariant();
+    qvariantPtr = new (&allocData) QVariant(metaType);
     type = QVariantWrappedType;
 
-    QVariant v = ExecutionEngine::toVariant(value, metaType);
-
-    if (v.metaType() == metaType) {
-        *qvariantPtr = std::move(v);
-        return true;
-    }
-
-    if (v.canConvert(metaType)) {
-        *qvariantPtr = std::move(v);
-        qvariantPtr->convert(metaType);
-        return true;
-    }
-
-    const QQmlMetaObject mo = QQmlMetaType::rawMetaObjectForType(metaType);
-    if (!mo.isNull() && v.metaType().flags().testFlag(QMetaType::PointerToQObject)) {
-        QObject *obj = QQmlMetaType::toQObject(v);
-
-        if (obj != nullptr && !QQmlMetaObject::canConvert(obj, mo)) {
-            *qvariantPtr = QVariant(metaType, nullptr);
-            return false;
-        }
-
-        *qvariantPtr = QVariant(metaType, &obj);
-        return true;
-    }
-
-    *qvariantPtr = QVariant(metaType, (void *)nullptr);
-    return false;
+    return ExecutionEngine::metaTypeFromJS(value, metaType, qvariantPtr->data());
 }
 
 ReturnedValue CallArgument::toValue(ExecutionEngine *engine)

tests/auto/qml/qqmlvaluetypeproviders/data/structuredValueTypes.qml

@@ -40,10 +40,13 @@ MyTypeObject {
         r2 = {x: 9, y: 10, width: 11, height: 12};
         c3 = 99;
         b2 = {i: 11, c: 15, p: {x: 4} }
-
+        acceptConstructible(object)
         c4 = {foo: 11};
     }
 
     barren: ({i: 17})
     function changeBarren() { barren = "foos" }
+
+    property QtObject object: QtObject {}
+    property constructible fromObject: object
 }

tests/auto/qml/qqmlvaluetypeproviders/testtypes.h

@@ -33,6 +33,7 @@ struct ConstructibleValueType
 public:
     ConstructibleValueType() = default;
     Q_INVOKABLE ConstructibleValueType(int foo) : m_foo(foo) {}
+    Q_INVOKABLE ConstructibleValueType(QObject *) : m_foo(67) {}
 
     int foo() const { return m_foo; }
 
@@ -350,6 +351,11 @@ public:
         emit barrenChanged();
     }
 
+    Q_INVOKABLE void acceptConstructible(const ConstructibleValueType &a)
+    {
+        setAVariant(QVariant::fromValue(a));
+    }
+
 signals:
     void changed();
     void runScript();

tests/auto/qml/qqmlvaluetypeproviders/tst_qqmlvaluetypeproviders.cpp

@@ -358,6 +358,11 @@ void tst_qqmlvaluetypeproviders::structured()
 
     QMetaObject::invokeMethod(o.data(), "changeBarren");
     QCOMPARE(o->property("barren").value<BarrenValueType>(), BarrenValueType(QString()));
+
+    QCOMPARE(o->property("fromObject").value<ConstructibleValueType>(),
+             ConstructibleValueType(nullptr));
+    QCOMPARE(o->property("aVariant").value<ConstructibleValueType>(),
+             ConstructibleValueType(nullptr));
 }
 
 void tst_qqmlvaluetypeproviders::recursive()