From cdadd1bdb3f0137659f0f82b06628d0b20b858e3 Mon Sep 17 00:00:00 2001
From: Volker Hilsheimer <volker.hilsheimer@qt.io>
Date: Mon, 10 Oct 2022 14:25:45 +0200
Subject: [PATCH] Allow programmatic closing of windows that are modally
 blocked
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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>
---
 src/gui/kernel/qguiapplication.cpp            |  5 +++--
 tests/auto/gui/kernel/qwindow/tst_qwindow.cpp | 17 +++++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 44533bef4e7..b6a505375f4 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -2645,8 +2645,9 @@ void QGuiApplicationPrivate::processCloseEvent(QWindowSystemInterfacePrivate::Cl
 {
     if (e->window.isNull())
         return;
-    if (e->window.data()->d_func()->blockedByModalWindow) {
-        // a modal window is blocking this window, don't allow close events through
+    if (e->window.data()->d_func()->blockedByModalWindow && !e->window.data()->d_func()->inClose) {
+        // a modal window is blocking this window, don't allow close events through, unless they
+        // originate from a call to QWindow::close.
         return;
     }
 
diff --git a/tests/auto/gui/kernel/qwindow/tst_qwindow.cpp b/tests/auto/gui/kernel/qwindow/tst_qwindow.cpp
index e0e5999910a..123aa84bbc9 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()
 {