V4: change string flattening to be iterative and use a worklist.

And not recursive, because that might blow out of stack space.

Task-number: QTBUG-39520
Change-Id: Id961d4af03a543d3efa173f976626cf2dae4f483
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 6b37163b40..c68f1190dd 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -325,6 +325,7 @@ private slots:
     void importedScriptsAccessOnObjectWithInvalidContext();
     void contextObjectOnLazyBindings();
     void garbageCollectionDuringCreation();
+    void qtbug_39520();
 
 private:
 //    static void propertyVarWeakRefCallback(v8::Persistent<v8::Value> object, void* parameter);
@@ -7665,6 +7666,30 @@ void tst_qqmlecmascript::garbageCollectionDuringCreation()
     QCOMPARE(container->dataChildren.count(), 0);
 }
 
+void tst_qqmlecmascript::qtbug_39520()
+{
+    QQmlComponent component(&engine);
+    component.setData("import QtQuick 2.0\n"
+                      "Item {\n"
+                      "    property string s\n"
+                      "    Component.onCompleted: test()\n"
+                      "    function test() {\n"
+                      "    var count = 1 * 1000 * 1000\n"
+                      "    var t = ''\n"
+                      "    for (var i = 0; i < count; ++i)\n"
+                      "        t += 'testtest ' + i + '\n'\n"
+                      "    s = t\n"
+                      "    }\n"
+                      "}\n",
+                      QUrl());
+
+    QScopedPointer<QObject> object(component.create());
+    QVERIFY(!object.isNull());
+
+    QString s = object->property("s").toString();
+    QCOMPARE(s.count('\n'), 1 * 1000 * 1000);
+}
+
 QTEST_MAIN(tst_qqmlecmascript)
 
 #include "tst_qqmlecmascript.moc"