Add test-case for QWidget closing exits event loop

Also when closed by destruction, which as of today doesn't call
QWidget::close and therefore also not QWindow::close.

Change-Id: I426255e2274eae9262243c769df2264fbaa915b0
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 7c85ad307b1c9d69b4a9e5424f111d031649c44a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
index 7ca08993ab..21e77378d1 100644
--- a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
+++ b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
@@ -52,6 +52,7 @@
 #include <qmainwindow.h>
 #include <qdockwidget.h>
 #include <qrandom.h>
+#include <qsignalspy.h>
 #include <qstylehints.h>
 #include <qtoolbar.h>
 #include <qtoolbutton.h>
@@ -425,6 +426,7 @@ private slots:
     void receivesApplicationFontChangeEvent();
     void receivesApplicationPaletteChangeEvent();
     void deleteWindowInCloseEvent();
+    void quitOnClose();
 
 private:
     bool ensureScreenSize(int width, int height);
@@ -11946,5 +11948,34 @@ void tst_QWidget::deleteWindowInCloseEvent()
     QVERIFY(true);
 }
 
+/*!
+    Verify that both closing and deleting the last (only) window-widget
+    exits the application event loop.
+*/
+void tst_QWidget::quitOnClose()
+{
+    QSignalSpy quitSpy(qApp, &QApplication::lastWindowClosed);
+
+    std::unique_ptr<QWidget>widget(new QWidget);
+    widget->show();
+    QVERIFY(QTest::qWaitForWindowExposed(widget.get()));
+
+    // QGuiApplication::lastWindowClosed is documented to only be emitted
+    // when we are in exec()
+    QTimer::singleShot(0, widget.get(), [&]{
+        widget->close();
+    });
+    QApplication::exec();
+    QCOMPARE(quitSpy.count(), 1);
+
+    widget->show();
+    QVERIFY(QTest::qWaitForWindowExposed(widget.get()));
+    QTimer::singleShot(0, widget.get(), [&]{
+        widget.reset();
+    });
+    QApplication::exec();
+    QCOMPARE(quitSpy.count(), 2);
+}
+
 QTEST_MAIN(tst_QWidget)
 #include "tst_qwidget.moc"