Allow programmatic closing of windows that are modally blocked

In Qt 6, after changes such as 121fddcf5ae2ab238ef802e44b45ce62c56015f5,
we go through the QPA layer to close widget windows properly. Closing
and hiding of windows is now done in when we receive and handle the
window system's CloseEvent.

Such an event to a modally blocked window should be blocked, so that
users can't close a modally blocked window. However, if the event is the
result of a call to QWindow::close, then it should not be blocked.
Luckily, we know that the event is the result of such a call, so let
such events through. This restores compatibility with Qt 5, where it was
possible to first open a new dialog, and then close the previous dialog.

Add a test case.

Fixes: QTBUG-107188
Pick-to: 6.4 6.2
Change-Id: Id812c1fc36aa0e1a10dfb8d3a16a11d387289b05
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/auto/gui/kernel/qwindow/tst_qwindow.cpp b/tests/auto/gui/kernel/qwindow/tst_qwindow.cpp
index e0e5999910..123aa84bbc 100644
--- a/tests/auto/gui/kernel/qwindow/tst_qwindow.cpp
+++ b/tests/auto/gui/kernel/qwindow/tst_qwindow.cpp
@@ -70,6 +70,7 @@ private slots:
     void modalWithChildWindow();
     void modalWindowModallity();
     void modalWindowPosition();
+    void modalCloseWhileBlocked();
 #ifndef QT_NO_CURSOR
     void modalWindowEnterEventOnHide_QTBUG35109();
     void spuriousMouseMove();
@@ -2267,6 +2268,22 @@ void tst_QWindow::modalWindowPosition()
     QCOMPARE(window.geometry(), origGeo);
 }
 
+void tst_QWindow::modalCloseWhileBlocked()
+{
+    QWindow first;
+    first.setModality(Qt::ApplicationModal);
+    first.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&first));
+
+    QWindow second;
+    second.setModality(Qt::ApplicationModal);
+    second.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&first));
+
+    first.close();
+    QTRY_VERIFY(!first.isVisible());
+}
+
 #ifndef QT_NO_CURSOR
 void tst_QWindow::modalWindowEnterEventOnHide_QTBUG35109()
 {