Dialogs: clean up native dialogs when object gets destroyed

QWidget::setVisible is virtual, and called via hide() by both the
QDialog and the QWidget destructor. A dialog that becomes invisible
when getting destroyed will at most execute the QDialog override.
Subclassing QDialog and overriding setVisible() to update the state
of the native platform dialog will not work, unless we explicitly
call hide() in the respective subclass's destructor.

Since e0bb9e81ab1a9d71f2893844ea82, QDialogPrivate::setVisible is
also virtual, and gets called by QDialog::setVisible. So the clean
solution is to move the implementation of the native dialog status
update into an override of QDialogPrivate::setVisible.

Add test that verifies that the transient parent of the dialog
becomes inactive when the (native) dialog shows (and skip if that
fails), and then becomes active again when the (native) dialog is
closed through the destructor of the Q*Dialog class. The test of
QFileDialog has to be skipped on Android for the same reason as the
widgetlessNativeDialog.

Fixes: QTBUG-116277
Pick-to: 6.6 6.5
Change-Id: Ie3f93980d8653b8d933bf70aac3ef90de606f0ef
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

4 files changed, 131 insertions, 3 deletions

diff --git a/tests/auto/widgets/dialogs/qcolordialog/tst_qcolordialog.cpp b/tests/auto/widgets/dialogs/qcolordialog/tst_qcolordialog.cpp
index c7c9d3d359..aa7bddd81a 100644
--- a/tests/auto/widgets/dialogs/qcolordialog/tst_qcolordialog.cpp
+++ b/tests/auto/widgets/dialogs/qcolordialog/tst_qcolordialog.cpp
@@ -29,6 +29,8 @@ private slots:
     void QTBUG_43548_initialColor();
     void hexColor_data();
     void hexColor();
+
+    void hideNativeByDestruction();
 };
 
 class TestNativeDialog : public QColorDialog
@@ -179,5 +181,32 @@ void tst_QColorDialog::hexColor()
     QCOMPARE(color.name(QColor::HexRgb), expectedHexColor.toLower());
 }
 
+void tst_QColorDialog::hideNativeByDestruction()
+{
+    QWidget window;
+    QWidget *child = new QWidget(&window);
+    QPointer<QColorDialog> dialog = new QColorDialog(child);
+    // Make it application modal so that we don't end up with a sheet on macOS
+    dialog->setWindowModality(Qt::ApplicationModal);
+    window.show();
+    QVERIFY(QTest::qWaitForWindowActive(&window));
+    dialog->open();
+
+    // We test that the dialog opens and closes by watching the activation of the
+    // transient parent window. If it doesn't deactivate, then we have to skip.
+    const auto windowActive = [&window]{ return window.isActiveWindow(); };
+    const auto windowInactive = [&window]{ return !window.isActiveWindow(); };
+    if (!QTest::qWaitFor(windowInactive, 2000))
+        QSKIP("Dialog didn't activate");
+
+    // This should destroy the dialog and close the native window
+    child->deleteLater();
+    QTRY_VERIFY(!dialog);
+    // If the native window is still open, then the transient parent can't become
+    // active
+    window.activateWindow();
+    QVERIFY(QTest::qWaitFor(windowActive));
+}
+
 QTEST_MAIN(tst_QColorDialog)
 #include "tst_qcolordialog.moc"
diff --git a/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp b/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
index 4424ecec62..23390dc04c 100644
--- a/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
+++ b/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
@@ -128,9 +128,10 @@ private slots:
     void QTBUG49600_nativeIconProviderCrash();
     void focusObjectDuringDestruction();
 
-    // NOTE: Please keep widgetlessNativeDialog() as the LAST test!
+    // NOTE: Please keep widgetlessNativeDialog() and
+    // hideNativeByDestruction() as the LAST tests!
     //
-    // widgetlessNativeDialog() is the only test function that creates
+    // widgetlessNativeDialog() are the only test functions that create
     // a native file dialog instance. GTK+ versions prior 3.15.5 have
     // a nasty bug (https://bugzilla.gnome.org/show_bug.cgi?id=725164)
     // in GtkFileChooserWidget, which makes it leak its folder change
@@ -141,6 +142,7 @@ private slots:
     // The crash has been fixed in GTK+ 3.15.5, but the RHEL 7.2 CI has
     // GTK+ 3.14.13 installed (QTBUG-55276).
     void widgetlessNativeDialog();
+    void hideNativeByDestruction();
 
 private:
     void cleanupSettingsFile();
@@ -1437,7 +1439,7 @@ void tst_QFiledialog::widgetlessNativeDialog()
         QSKIP("This platform always uses widgets to realize its QFileDialog, instead of the native file dialog.");
 #ifdef Q_OS_ANDROID
     // QTBUG-101194
-    QSKIP("Android: This keeeps the window open. Figure out why.");
+    QSKIP("Android: This keeps the window open. Figure out why.");
 #endif
     QApplication::setAttribute(Qt::AA_DontUseNativeDialogs, false);
     QFileDialog fd;
@@ -1451,6 +1453,46 @@ void tst_QFiledialog::widgetlessNativeDialog()
     QApplication::setAttribute(Qt::AA_DontUseNativeDialogs, true);
 }
 
+void tst_QFiledialog::hideNativeByDestruction()
+{
+    if (!QGuiApplicationPrivate::platformTheme()->usePlatformNativeDialog(QPlatformTheme::FileDialog))
+        QSKIP("This platform always uses widgets to realize its QFileDialog, instead of the native file dialog.");
+
+#ifdef Q_OS_ANDROID
+    // QTBUG-101194
+    QSKIP("Android: This keeps the native window open. Figure out why.");
+#endif
+
+    QApplication::setAttribute(Qt::AA_DontUseNativeDialogs, false);
+    auto resetAttribute = qScopeGuard([]{
+        QApplication::setAttribute(Qt::AA_DontUseNativeDialogs, true);
+    });
+
+    QWidget window;
+    QWidget *child = new QWidget(&window);
+    QPointer<QFileDialog> dialog = new QFileDialog(child);
+    // Make it application modal so that we don't end up with a sheet on macOS
+    dialog->setWindowModality(Qt::ApplicationModal);
+    window.show();
+    QVERIFY(QTest::qWaitForWindowActive(&window));
+    dialog->open();
+
+    // We test that the dialog opens and closes by watching the activation of the
+    // transient parent window. If it doesn't deactivate, then we have to skip.
+    const auto windowActive = [&window]{ return window.isActiveWindow(); };
+    const auto windowInactive = [&window]{ return !window.isActiveWindow(); };
+    if (!QTest::qWaitFor(windowInactive, 2000))
+        QSKIP("Dialog didn't activate");
+
+    // This should destroy the dialog and close the native window
+    child->deleteLater();
+    QTRY_VERIFY(!dialog);
+    // If the native window is still open, then the transient parent can't become
+    // active
+    window.activateWindow();
+    QVERIFY(QTest::qWaitFor(windowActive, 2000));
+}
+
 void tst_QFiledialog::selectedFilesWithoutWidgets()
 {
     // Test for a crash when widgets are not instantiated yet.
diff --git a/tests/auto/widgets/dialogs/qfontdialog/tst_qfontdialog.cpp b/tests/auto/widgets/dialogs/qfontdialog/tst_qfontdialog.cpp
index 0a77bc3808..fa808712ac 100644
--- a/tests/auto/widgets/dialogs/qfontdialog/tst_qfontdialog.cpp
+++ b/tests/auto/widgets/dialogs/qfontdialog/tst_qfontdialog.cpp
@@ -45,6 +45,7 @@ private slots:
     void qtbug_41513_stylesheetStyle();
 #endif
 
+    void hideNativeByDestruction();
 
 private:
     void runSlotWithFailsafeTimer(const char *member);
@@ -238,5 +239,32 @@ void tst_QFontDialog::testNonStandardFontSize()
         qWarning("Fail using a non-standard font size.");
 }
 
+void tst_QFontDialog::hideNativeByDestruction()
+{
+    QWidget window;
+    QWidget *child = new QWidget(&window);
+    QPointer<QFontDialog> dialog = new QFontDialog(child);
+    // Make it application modal so that we don't end up with a sheet on macOS
+    dialog->setWindowModality(Qt::ApplicationModal);
+    window.show();
+    QVERIFY(QTest::qWaitForWindowActive(&window));
+    dialog->open();
+
+    // We test that the dialog opens and closes by watching the activation of the
+    // transient parent window. If it doesn't deactivate, then we have to skip.
+    const auto windowActive = [&window]{ return window.isActiveWindow(); };
+    const auto windowInactive = [&window]{ return !window.isActiveWindow(); };
+    if (!QTest::qWaitFor(windowInactive, 2000))
+        QSKIP("Dialog didn't activate");
+
+    // This should destroy the dialog and close the native window
+    child->deleteLater();
+    QTRY_VERIFY(!dialog);
+    // If the native window is still open, then the transient parent can't become
+    // active
+    window.activateWindow();
+    QVERIFY(QTest::qWaitFor(windowActive));
+}
+
 QTEST_MAIN(tst_QFontDialog)
 #include "tst_qfontdialog.moc"
diff --git a/tests/auto/widgets/dialogs/qmessagebox/tst_qmessagebox.cpp b/tests/auto/widgets/dialogs/qmessagebox/tst_qmessagebox.cpp
index 3679a9367d..8985243e36 100644
--- a/tests/auto/widgets/dialogs/qmessagebox/tst_qmessagebox.cpp
+++ b/tests/auto/widgets/dialogs/qmessagebox/tst_qmessagebox.cpp
@@ -60,6 +60,8 @@ private slots:
     void overrideDone_data();
     void overrideDone();
 
+    void hideNativeByDestruction();
+
     void cleanup();
 };
 
@@ -798,5 +800,32 @@ void tst_QMessageBox::acceptedRejectedSignals_data()
     addCustomButtonsData();
 }
 
+void tst_QMessageBox::hideNativeByDestruction()
+{
+    QWidget window;
+    QWidget *child = new QWidget(&window);
+    QPointer<QMessageBox> dialog = new QMessageBox(child);
+    // Make it application modal so that we don't end up with a sheet on macOS
+    dialog->setWindowModality(Qt::ApplicationModal);
+    window.show();
+    QVERIFY(QTest::qWaitForWindowActive(&window));
+    dialog->open();
+
+    // We test that the dialog opens and closes by watching the activation of the
+    // transient parent window. If it doesn't deactivate, then we have to skip.
+    const auto windowActive = [&window]{ return window.isActiveWindow(); };
+    const auto windowInactive = [&window]{ return !window.isActiveWindow(); };
+    if (!QTest::qWaitFor(windowInactive, 2000))
+        QSKIP("Dialog didn't activate");
+
+    // This should destroy the dialog and close the native window
+    child->deleteLater();
+    QTRY_VERIFY(!dialog);
+    // If the native window is still open, then the transient parent can't become
+    // active
+    window.activateWindow();
+    QVERIFY(QTest::qWaitFor(windowActive));
+}
+
 QTEST_MAIN(tst_QMessageBox)
 #include "tst_qmessagebox.moc"