Add recursion guard to QQuickApplicationWindowPrivate::relayout()

relayout() might change the size of the header, footer or contentitem
When one of those items changes, QQuickApplicationWindowPrivate will
get notified by that through
QQuickApplicationWindowPrivate::itemGeometryChanged().
itemGeometryChanged() will then call relayout()... (*recursed*).

Pick-to: 5.15 6.2
Task-number: QTBUG-87708
Change-Id: I9403952e776afb2be37d009642c65b5520c79341
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

2 files changed, 103 insertions, 0 deletions

diff --git a/tests/auto/qquickapplicationwindow/data/layoutLayout.qml b/tests/auto/qquickapplicationwindow/data/layoutLayout.qml
new file mode 100644
index 00000000..670306fa
--- /dev/null
+++ b/tests/auto/qquickapplicationwindow/data/layoutLayout.qml
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+
+ApplicationWindow {
+    width: 200
+    height: 200
+    visible: true
+
+    header: RowLayout {
+        Rectangle { color: "red"; implicitWidth: 20; implicitHeight: 20; Layout.fillWidth: true}
+    }
+    footer: ColumnLayout {
+        Rectangle { color: "green"; implicitWidth: 20; implicitHeight: 20; Layout.fillWidth: true}
+    }
+}
diff --git a/tests/auto/qquickapplicationwindow/tst_qquickapplicationwindow.cpp b/tests/auto/qquickapplicationwindow/tst_qquickapplicationwindow.cpp
index 7816622c..f6bf7d74 100644
--- a/tests/auto/qquickapplicationwindow/tst_qquickapplicationwindow.cpp
+++ b/tests/auto/qquickapplicationwindow/tst_qquickapplicationwindow.cpp
@@ -79,6 +79,7 @@ private slots:
     void focusAfterPopupClosed();
     void clearFocusOnDestruction();
     void layout();
+    void layoutLayout();
     void componentComplete();
     void opacity();
 };
@@ -869,6 +870,42 @@ void tst_QQuickApplicationWindow::layout()
     QCOMPARE(content->height(), qreal(window->height()));
 }
 
+void tst_QQuickApplicationWindow::layoutLayout()
+{
+    QQmlEngine engine;
+    QQmlComponent component(&engine);
+    component.loadUrl(testFileUrl("layoutLayout.qml"));
+    QScopedPointer<QObject> object(component.create());
+    QVERIFY2(!object.isNull(), qPrintable(component.errorString()));
+
+    QQuickApplicationWindow* window = qobject_cast<QQuickApplicationWindow*>(object.data());
+    QVERIFY(window);
+    QVERIFY(QTest::qWaitForWindowExposed(window));
+
+    QQuickItem *content = window->contentItem();
+    QVERIFY(content);
+    QQuickItem *header = window->header();
+    QVERIFY(header);
+    QQuickItem *footer = window->footer();
+    QVERIFY(footer);
+
+    QQuickItem *headerChild = header->findChild<QQuickItem*>();
+    QVERIFY(headerChild);
+    QCOMPARE(header->x(), 0.0);
+    QCOMPARE(header->y(), -header->height());
+    QCOMPARE(header->width(), qreal(window->width()));
+    QCOMPARE(headerChild->width(), qreal(window->width()));
+    QVERIFY(header->height() > 0);
+
+    QQuickItem *footerChild = header->findChild<QQuickItem*>();
+    QVERIFY(footerChild);
+    QCOMPARE(footer->x(), 0.0);
+    QCOMPARE(footer->y(), content->height());
+    QCOMPARE(footer->width(), qreal(window->width()));
+    QCOMPARE(footerChild->width(), qreal(window->width()));
+    QVERIFY(footer->height() > 0.0);
+}
+
 class FriendlyApplicationWindow : public QQuickApplicationWindow
 {
     friend class tst_QQuickApplicationWindow;