Avoid duplicate value type creation

We can actually produce an uninitialized but pre-allocated QVariant
using QVariant::Private. Using the new in-place construction support in
QMetaObject, we can minimize the amount of copying necessary for value
types.

Fixes: QTBUG-108789
Change-Id: I6b748794a6adbf6558e1e3086eab80fcfb3154a0
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/qml/jsruntime/qv4sequenceobject.cpp b/src/qml/jsruntime/qv4sequenceobject.cpp
index 132084705c..d33466a7fa 100644
--- a/src/qml/jsruntime/qv4sequenceobject.cpp
+++ b/src/qml/jsruntime/qv4sequenceobject.cpp
@@ -714,9 +714,9 @@ QVariant SequencePrototype::toVariant(const QV4::Value &array, QMetaType typeHin
             } else {
                 const QMetaType originalType = variant.metaType();
                 if (originalType != valueMetaType) {
-                    QVariant converted(valueMetaType);
-                    if (QQmlValueTypeProvider::createValueType(
-                                variant, valueMetaType, converted.data())) {
+                    const QVariant converted = QQmlValueTypeProvider::createValueType(
+                                variant, valueMetaType);
+                    if (converted.isValid()) {
                         variant = converted;
                     } else if (!variant.convert(valueMetaType)) {
                         qWarning().noquote()
@@ -725,7 +725,7 @@ QVariant SequencePrototype::toVariant(const QV4::Value &array, QMetaType typeHin
                                    .arg(QString::number(i),
                                         QString::fromUtf8(originalType.name()),
                                         QString::fromUtf8(valueMetaType.name()));
-                        variant = converted;
+                        variant = QVariant(valueMetaType);
                     }
                 }
                 meta->addValueAtEnd(result.data(), variant.constData());