V4: Avoid copying WeakValues with wrapped QObjects

Such WeakValues are kept alive until the respective QObject is deleted.
Therefore they are quite expensive. In this case we don't actually need
a copy as on retrieval we only want a ReturnValue and on inserting we
just want to replace the value in the map.

Fixes: QTBUG-71817
Change-Id: I385c55140337d468289046243941077ba1ff61a3
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

1 files changed, 1 insertions, 3 deletions

diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 8cdec2f6ee..9344a231ff 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -2226,9 +2226,7 @@ void QmlSignalHandler::initProto(ExecutionEngine *engine)
 
 void MultiplyWrappedQObjectMap::insert(QObject *key, Heap::Object *value)
 {
-    QV4::WeakValue v;
-    v.set(value->internalClass->engine, value);
-    QHash<QObject*, QV4::WeakValue>::insert(key, v);
+    QHash<QObject*, QV4::WeakValue>::operator[](key).set(value->internalClass->engine, value);
     connect(key, SIGNAL(destroyed(QObject*)), this, SLOT(removeDestroyedObject(QObject*)));
 }