From 945c8bf54dcb14a787966988ebf40cededd321cc Mon Sep 17 00:00:00 2001
From: Volker Hilsheimer <volker.hilsheimer@qt.io>
Date: Fri, 1 Nov 2024 14:45:28 +0100
Subject: [PATCH] Cocoa: Use sheetParent to close sheet instead of
 transientParent
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If the window that the sheet (as created for a modal dialog) lives in
has already been destroyed by the time the sheet is hidden, then we used
to trip an assertion. Instead, always use the sheetParent, which is
still alive.

Add a test case that asserts without the fix.

Fixes: QTBUG-128302
Change-Id: I4c399b73e2552bab79358c5505f403efa8e4f80b
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 332f49f2d8c5675bab8bde6acfb377d567961d4a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/plugins/platforms/cocoa/qcocoawindow.mm   | 10 +++-------
 .../widgets/dialogs/qdialog/tst_qdialog.cpp   | 20 +++++++++++++++++++
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index e5c643751f6..85f7bbb5c1f 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -472,14 +472,10 @@ void QCocoaWindow::setVisible(bool visible)
     } else {
         // Window not visible, hide it
         if (isContentView()) {
-            if (eventDispatcher()->hasModalSession()) {
+            if (eventDispatcher()->hasModalSession())
                 eventDispatcher()->endModalSession(window());
-            } else {
-                if ([m_view.window isSheet]) {
-                    Q_ASSERT_X(parentCocoaWindow, "QCocoaWindow", "Window modal dialog has no transient parent.");
-                    [parentCocoaWindow->nativeWindow() endSheet:m_view.window];
-                }
-            }
+            else if ([m_view.window isSheet])
+                [m_view.window.sheetParent endSheet:m_view.window];
 
             // Note: We do not guard the order out by checking NSWindow.visible, as AppKit will
             // in some cases, such as when hiding the application, order out and make a window
diff --git a/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp b/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
index 13f971f5f05..e970ea2810a 100644
--- a/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
+++ b/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
@@ -66,6 +66,8 @@ private slots:
     void deleteOnDone();
     void quitOnDone();
     void focusWidgetAfterOpen();
+
+    void closeParentOfVisibleDialog();
 };
 
 // Testing get/set functions
@@ -768,5 +770,23 @@ void tst_QDialog::focusWidgetAfterOpen()
     QCOMPARE(dialog.focusWidget(), static_cast<QWidget *>(pb2));
 }
 
+void tst_QDialog::closeParentOfVisibleDialog()
+{
+    QWidget widget;
+    widget.show();
+
+    // On macOS, this dialog becomes a sheet and triggered an assert when
+    // the widget it lived in was already gone by the time the sheet
+    // got closed. QTBUG-128302
+    QDialog dialog(&widget);
+    dialog.open();
+
+    QTimer::singleShot(0, &widget, [&]{
+        widget.close();
+    });
+
+    QTRY_VERIFY(!widget.isVisible());
+}
+
 QTEST_MAIN(tst_QDialog)
 #include "tst_qdialog.moc"