From da9da78adc4c82534c5648ed54df90e2df87225d Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Mon, 10 Jun 2024 16:14:47 +0200
Subject: [PATCH] QGraphicsView: add a failing test

Task-number: QTBUG-53974
Pick-to: 6.7 6.5
Change-Id: Ibff3e32080a2978e533bd1f3215fec81bedb72b7
Reviewed-by: David Faure <david.faure@kdab.com>
(cherry picked from commit f27534158e64ed1fb3aacc090995ea4b2d4b26fe)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 .../qgraphicsview/tst_qgraphicsview.cpp       | 91 +++++++++++++++++++
 1 file changed, 91 insertions(+)

diff --git a/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp b/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp
index 7ed1f28b0a9..ed99cd93a8f 100644
--- a/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp
+++ b/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp
@@ -26,6 +26,7 @@
 #include <QtWidgets/QStyle>
 #include <QtWidgets/QPushButton>
 #include <QtWidgets/QScroller>
+#include <QtWidgets/QStackedWidget>
 #if QT_CONFIG(opengl)
 #include <QtOpenGLWidgets/QOpenGLWidget>
 #endif
@@ -114,6 +115,7 @@ protected:
 #if defined QT_BUILD_INTERNAL
 class FriendlyGraphicsScene : public QGraphicsScene
 {
+    using QGraphicsScene::QGraphicsScene;
     friend class tst_QGraphicsView;
     Q_DECLARE_PRIVATE(QGraphicsScene);
 };
@@ -253,6 +255,9 @@ private slots:
     void QTBUG_70255_scrollTo();
 #ifndef QT_NO_CURSOR
     void QTBUG_7438_cursor();
+#endif
+#ifdef QT_BUILD_INTERNAL
+    void QTBUG_53974_mismatched_hide_show_events();
 #endif
     void resizeContentsOnItemDrag_data();
     void resizeContentsOnItemDrag();
@@ -4975,6 +4980,92 @@ void tst_QGraphicsView::QTBUG_70255_scrollTo()
     QCOMPARE(point, QPoint(0, -500));
 }
 
+#ifdef QT_BUILD_INTERNAL
+void tst_QGraphicsView::QTBUG_53974_mismatched_hide_show_events()
+{
+    QGraphicsView *view = new QGraphicsView;
+    FriendlyGraphicsScene *scene = new FriendlyGraphicsScene(view);
+    view->setScene(scene);
+
+    QStackedWidget *lowLevel = new QStackedWidget;
+    lowLevel->addWidget(new QLabel);
+    lowLevel->addWidget(view);
+
+    QStackedWidget topLevel;
+    topLevel.addWidget(new QLabel);
+    topLevel.addWidget(lowLevel);
+
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    topLevel.show();
+    topLevel.activateWindow();
+    QVERIFY(QTest::qWaitForWindowActive(&topLevel));
+
+    // Starting point
+    QCOMPARE_EQ(topLevel.currentIndex(), 0);
+    QCOMPARE_EQ(lowLevel->currentIndex(), 0);
+
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    // lowLevel is not visible. Changing the current index there
+    // should not affect the refcount.
+    lowLevel->setCurrentIndex(1);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    lowLevel->setCurrentIndex(0);
+    QEXPECT_FAIL("", "The view was already hidden, so the refcount should still be 0", Continue);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+    scene->d_func()->activationRefCount = 0;
+
+    // Make lowLevel visible.
+    topLevel.setCurrentIndex(1);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    // Show and hide the QGV a couple of times.
+    lowLevel->setCurrentIndex(1);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 1);
+
+    lowLevel->setCurrentIndex(0);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    lowLevel->setCurrentIndex(1);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 1);
+
+    lowLevel->setCurrentIndex(0);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    // Make lowLevel hidden again.
+    topLevel.setCurrentIndex(0);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    // Change the current index in the hidden lowLevel
+    lowLevel->setCurrentIndex(1);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    lowLevel->setCurrentIndex(0);
+    QEXPECT_FAIL("", "The view was already hidden, so the refcount should still be 0", Continue);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+    scene->d_func()->activationRefCount = 0;
+
+    // Make lowLevel and the QGV visible.
+    lowLevel->setCurrentIndex(1);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    topLevel.setCurrentIndex(1);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 1);
+
+    // Make lowLevel hidden (keeping the QGV as current index).
+    topLevel.setCurrentIndex(0);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+
+    // Hide the QGV:
+    lowLevel->setCurrentIndex(0);
+    QEXPECT_FAIL("", "The view was already hidden, so the refcount should still be 0", Continue);
+    QCOMPARE_EQ(scene->d_func()->activationRefCount, 0);
+    scene->d_func()->activationRefCount = 0;
+}
+#endif
+
 void tst_QGraphicsView::resizeContentsOnItemDrag_data()
 {
     QTest::addColumn<Qt::Alignment>("alignment");