V4: Mark InternalClass parents when running GC

We need to preserve them as they notify us about protoId related
changes. In order to avoid wasting heap space in case many properties
are added and removed from the same object, we put a mechanism in place
to rebuild the InternalClass hierarchy if many redundant transitions are
detected.

Amends commit 69d76d59cec0dcff4c52eef24e779fbef14beeca.

Fixes: QTBUG-91687
Task-number: QTBUG-58559
Change-Id: I3238931b5919ed2b98059e0b7f928334284ce7bf
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit 0b9fa18dfefc06f542bd0c98b7e41fa14aa0c2cf)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 40e8fbe26b..87995b0aca 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -407,6 +407,8 @@ private slots:
     void functionNameInFunctionScope();
     void functionAsDefaultArgument();
 
+    void internalClassParentGc();
+
 private:
 //    static void propertyVarWeakRefCallback(v8::Persistent<v8::Value> object, void* parameter);
     static void verifyContextLifetime(const QQmlRefPointer<QQmlContextData> &ctxt);
@@ -10069,6 +10071,15 @@ void tst_qqmlecmascript::functionAsDefaultArgument()
     QCOMPARE(root->objectName(), "didRun");
 }
 
+void tst_qqmlecmascript::internalClassParentGc()
+{
+    QQmlEngine engine;
+    QQmlComponent component(&engine, testFileUrl("internalClassParentGc.qml"));
+    QScopedPointer root(component.create());
+    QVERIFY(root);
+    QCOMPARE(root->objectName(), "3");
+}
+
 QTEST_MAIN(tst_qqmlecmascript)
 
 #include "tst_qqmlecmascript.moc"