Ensure that child windows are visible again when showing their parent

When a window is closed, then it will cause the child windows to be
closed as well as a result. Therefore in order to ensure that they are
shown again as a result, we need to remove the WA_WState_ExplicitShowHide
attribute if the widget was not already hidden before. This enables us to
test for this attribute when calling showChildren(), so that if the
window has a windowHandle then we can make sure that this widget is shown
again.

Fixes: QTBUG-73021
Change-Id: I1186242b889899dfcd38d782a67567348e2055ee
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit ccd3bf0871b81dfc09bb469b161f32dfb47ee53e)

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
index 58c61d746a..c042a92a6a 100644
--- a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
+++ b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
@@ -395,6 +395,7 @@ private slots:
     void tabletTracking();
 
     void closeEvent();
+    void closeWithChildWindow();
 
 private:
     bool ensureScreenSize(int width, int height);
@@ -11067,5 +11068,27 @@ void tst_QWidget::closeEvent()
     QCOMPARE(widget.closeCount, 1);
 }
 
+void tst_QWidget::closeWithChildWindow()
+{
+    QWidget widget;
+    auto childWidget = new QWidget(&widget);
+    childWidget->setAttribute(Qt::WA_NativeWindow);
+    childWidget->windowHandle()->create();
+    widget.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&widget));
+    widget.windowHandle()->close();
+    widget.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&widget));
+    // Check that the child window inside the window is now visible
+    QVERIFY(childWidget->isVisible());
+
+    // Now explicitly hide the childWidget
+    childWidget->hide();
+    widget.windowHandle()->close();
+    widget.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&widget));
+    QVERIFY(!childWidget->isVisible());
+}
+
 QTEST_MAIN(tst_QWidget)
 #include "tst_qwidget.moc"