QML Binding: do not convert strings

The root cause for the issue is that QQmlObjectCreator::setPropertyValue
calls QQmlStringConverters::variantFromString on strings if the property
is of type QVariant. Unfortunately, this cannot be changed easily as the
current behavior is explicitly documented and tested in tst_qqmllanguage,
thus making it a breaking change.

As a workaround, QML Binding does now take a QJSValue instead of a
QVariant (making value a var property), which does not trigger the
conversion path.

Fixes: QTBUG-78943
Change-Id: I0b64dffdb6b84b2bab2bb85a8cb263e530c18570
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/qml/types/qqmlbind_p.h b/src/qml/types/qqmlbind_p.h
index 22007a3d25..ba040d2a0b 100644
--- a/src/qml/types/qqmlbind_p.h
+++ b/src/qml/types/qqmlbind_p.h
@@ -75,7 +75,7 @@ private:
     Q_INTERFACES(QQmlPropertyValueSource)
     Q_PROPERTY(QObject *target READ object WRITE setObject)
     Q_PROPERTY(QString property READ property WRITE setProperty)
-    Q_PROPERTY(QVariant value READ value WRITE setValue)
+    Q_PROPERTY(QJSValue value READ value WRITE setValue)
     Q_PROPERTY(bool when READ when WRITE setWhen)
     Q_PROPERTY(bool delayed READ delayed WRITE setDelayed REVISION 8)
     Q_PROPERTY(RestorationMode restoreMode READ restoreMode WRITE setRestoreMode
@@ -95,8 +95,8 @@ public:
     QString property() const;
     void setProperty(const QString &);
 
-    QVariant value() const;
-    void setValue(const QVariant &);
+    QJSValue value() const;
+    void setValue(const QJSValue &);
 
     bool delayed() const;
     void setDelayed(bool);