Make sure the QSplashScreen isn't closed instantly when calling finish()

Most of the time the widget passed in to finish() will not yet have a
window handle so it would just call close() straight away. This
way it ensures has a window handle.

Task-number: QTBUG-35757
Change-Id: I2e212a2ea496cc4e4bba57a8c2d0d127afc43e48
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

src/widgets/widgets/qsplashscreen.cpp

@@ -262,8 +262,11 @@ inline static bool waitForWindowExposed(QWindow *window, int timeout = 1000)
 
 void QSplashScreen::finish(QWidget *mainWin)
 {
-    if (mainWin && mainWin->windowHandle())
+    if (mainWin) {
+        if (!mainWin->windowHandle())
+            mainWin->createWinId();
         waitForWindowExposed(mainWin->windowHandle());
+    }
     close();
 }
 

tests/auto/widgets/widgets/qsplashscreen/qsplashscreen.pro

@@ -0,0 +1,4 @@
+CONFIG += testcase
+TARGET = tst_qsplashscreen
+QT += widgets testlib
+SOURCES += tst_qsplashscreen.cpp

tests/auto/widgets/widgets/qsplashscreen/tst_qsplashscreen.cpp

@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** 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 Digia. For licensing terms and
+** conditions see http://qt.digia.com/licensing. For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights. These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include <QtTest/QtTest>
+#include <QSplashScreen>
+
+class tst_QSplashScreen : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void checkCloseTime();
+};
+
+class CloseEventSplash : public QSplashScreen
+{
+public:
+    CloseEventSplash(const QPixmap &pix) : QSplashScreen(pix), receivedCloseEvent(false) {}
+    bool receivedCloseEvent;
+protected:
+    void closeEvent(QCloseEvent *event)
+    {
+        receivedCloseEvent = true;
+        QSplashScreen::closeEvent(event);
+    }
+};
+
+void tst_QSplashScreen::checkCloseTime()
+{
+    QPixmap pix(100, 100);
+    pix.fill(Qt::red);
+    CloseEventSplash splash(pix);
+    QVERIFY(!splash.receivedCloseEvent);
+    QWidget w;
+    splash.show();
+    QTimer::singleShot(500, &w, SLOT(show()));
+    QVERIFY(!splash.receivedCloseEvent);
+    splash.finish(&w);
+    QVERIFY(splash.receivedCloseEvent);
+    // We check the window handle because if this is not valid, then
+    // it can't have been exposed
+    QVERIFY(w.windowHandle());
+    QVERIFY(w.windowHandle()->isExposed());
+}
+
+QTEST_MAIN(tst_QSplashScreen)
+#include "tst_qsplashscreen.moc"