From b2862e2bd84d651c1f4fb2ced96ee6f40ea1f3e4 Mon Sep 17 00:00:00 2001
From: Andrei Golubev <andrei.golubev@qt.io>
Date: Fri, 20 Nov 2020 10:44:44 +0100
Subject: [PATCH 11/28] Fix QML property cache leaks of delegate items
The delegate items are destroyed through an event loop by a call to a
deleteLater(). This, however, doesn't work when the application is
in the process of exiting and the event loop is already closed (i.e.
we're in a stack unwinding part that starts after app.exec())
Combat this situation by setting a parent of the to-be-deleted object
to some QObject that will be destroyed e.g. QCoreApplication::instance()
before the program finishes. As QObjects clean their children on
destruction, this will make sure that we cleanup the previously leaking
thing regardless of the event loop
Added a test to check that delegates are destroyed (as a separate binary
due to differences in main() function)
Fixes: QTBUG-87228
Change-Id: I59066603b77497fe4fd8d051798c3e4b47c119f0
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit 3a5617dc45e281552b9c1f7a04f0561b8fa14d94)
---
src/qmlmodels/qqmldelegatemodel.cpp | 11 ++-
.../qquickview_extra/data/qtbug_87228.qml | 30 ++++++++
.../qquickview_extra/qquickview_extra.pro | 12 +++
.../qquickview_extra/tst_qquickview_extra.cpp | 77 +++++++++++++++++++
tests/auto/quick/quick.pro | 1 +
5 files changed, 130 insertions(+), 1 deletion(-)
create mode 100644 tests/auto/quick/qquickview_extra/data/qtbug_87228.qml
create mode 100644 tests/auto/quick/qquickview_extra/qquickview_extra.pro
create mode 100644 tests/auto/quick/qquickview_extra/tst_qquickview_extra.cpp
diff --git a/src/qmlmodels/qqmldelegatemodel.cpp b/src/qmlmodels/qqmldelegatemodel.cpp
index 725b9e8bc3..12c3d11937 100644
--- a/src/qmlmodels/qqmldelegatemodel.cpp
+++ b/src/qmlmodels/qqmldelegatemodel.cpp
@@ -1,6 +1,6 @@
/****************************************************************************
**
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2020 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtQml module of the Qt Toolkit.
@@ -2379,6 +2379,15 @@ void QQmlDelegateModelItem::destroyObject()
data->ownContext = nullptr;
data->context = nullptr;
}
+ /* QTBUG-87228: when destroying object at the application exit, the deferred
+ * parent by setting it to QCoreApplication instance if it's nullptr, so
+ * deletion won't work. Not to leak memory, make sure our object has a that
+ * the parent claims the object at the end of the lifetime. When not at the
+ * application exit, normal event loop will handle the deferred deletion
+ * earlier.
+ */
+ if (object->parent() == nullptr)
+ object->setParent(QCoreApplication::instance());
object->deleteLater();
if (attached) {
diff --git a/tests/auto/quick/qquickview_extra/data/qtbug_87228.qml b/tests/auto/quick/qquickview_extra/data/qtbug_87228.qml
new file mode 100644
index 0000000000..ff10eba23d
--- /dev/null
+++ b/tests/auto/quick/qquickview_extra/data/qtbug_87228.qml
@@ -0,0 +1,30 @@
+import QtQml 2.12
+import QtQml.Models 2.12
+import QtQuick 2.12
+
+Item {
+ height: 480
+ width: 320
+ Rectangle {
+ id: rootRect
+
+ function addItem(desc) {
+ myModel.append({"desc": desc});
+ }
+
+ Rectangle {
+ ListView {
+ objectName: "listView"
+ delegate: Text {
+ required property string desc
+ text: desc
+ }
+ model: ListModel { id: myModel }
+ }
+ }
+
+ Component.onCompleted: {
+ addItem("Test creation of a delegate with a property");
+ }
+ }
+}
diff --git a/tests/auto/quick/qquickview_extra/qquickview_extra.pro b/tests/auto/quick/qquickview_extra/qquickview_extra.pro
new file mode 100644
index 0000000000..b40af0ce19
--- /dev/null
+++ b/tests/auto/quick/qquickview_extra/qquickview_extra.pro
@@ -0,0 +1,12 @@
+CONFIG += testcase
+TARGET = tst_qquickview_extra
+macx:CONFIG -= app_bundle
+
+SOURCES += tst_qquickview_extra.cpp
+
+include (../../shared/util.pri)
+include (../shared/util.pri)
+
+TESTDATA = data/*
+
+QT += core-private gui-private qml-private quick-private testlib
diff --git a/tests/auto/quick/qquickview_extra/tst_qquickview_extra.cpp b/tests/auto/quick/qquickview_extra/tst_qquickview_extra.cpp
new file mode 100644
index 0000000000..f697a438bd
--- /dev/null
+++ b/tests/auto/quick/qquickview_extra/tst_qquickview_extra.cpp
@@ -0,0 +1,77 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <qtest.h>
+#include <QtTest/QSignalSpy>
+#include <QtQuick/qquickview.h>
+#include <QtQuick/qquickitem.h>
+#include <QtQml/qqmlengine.h>
+#include "../../shared/util.h"
+#include <QtCore/QDebug>
+#include <QtCore/QTimer>
+
+// Extra app-less tests
+class tst_QQuickViewExtra : public QQmlDataTest
+{
+ Q_OBJECT
+public:
+ tst_QQuickViewExtra();
+
+private slots:
+ void qtbug_87228();
+};
+
+tst_QQuickViewExtra::tst_QQuickViewExtra() { }
+
+void tst_QQuickViewExtra::qtbug_87228()
+{
+ QScopedPointer<QSignalSpy> deletionSpy;
+ {
+ int argc = 0;
+ QGuiApplication app(argc, nullptr);
+ QQuickView view;
+
+ view.setSource(testFileUrl("qtbug_87228.qml"));
+ view.show();
+ QTimer::singleShot(500, &app, QCoreApplication::quit);
+ app.exec();
+
+ QObject *listView = view.findChild<QObject *>("listView");
+ QVERIFY(listView);
+ QQuickItem *contentItem = listView->property("contentItem").value<QQuickItem *>();
+ QVERIFY(contentItem);
+ auto children = contentItem->childItems();
+ QVERIFY(children.size() > 0);
+ // for the sake of this test, any child would be suitable, so pick first
+ deletionSpy.reset(new QSignalSpy(children[0], SIGNAL(destroyed(QObject *))));
+ }
+ QCOMPARE(deletionSpy->count(), 1);
+}
+
+QTEST_APPLESS_MAIN(tst_QQuickViewExtra)
+
+#include "tst_qquickview_extra.moc"
diff --git a/tests/auto/quick/quick.pro b/tests/auto/quick/quick.pro
index 541bfdd527..45bcf8a9ce 100644
--- a/tests/auto/quick/quick.pro
+++ b/tests/auto/quick/quick.pro
@@ -85,6 +85,7 @@ QUICKTESTS += \
qquicktextinput \
qquickvisualdatamodel \
qquickview \
+ qquickview_extra \
qquickcanvasitem \
qquickdesignersupport \
qquickscreen \
--
2.31.1