From 81451de0e6f5f58247746ed17430a7b9514f20b9 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Wed, 26 Mar 2025 08:06:04 +0100
Subject: [PATCH] QDesktopUnixServices: don't leak the QDBusPendingCallWatcher

When, like in tst_QApplication::qtbug_103611(), a QApplication object
is destroyed without calling exec(), then QDesktopUnixServices leaked
its QDBusPendingCallWatcher, because the connection to the slot that
would deleteLater() the watcher was disconnected, and the watcher had
no QObject parent that would otherwise reap it.

Fix by actually deleting the watcher in ~QDesktopUnixServices(), if
it still exists (which implies disconnecting, of course).

This makes tst_QApplication asan-clean on Linux/X11 (was: "75466 bytes
leaked in 965 allocations").

Amends de609d84b9cee4a481d1718c00b09105d8c2ae69.

Pick-to: 6.8 6.5
Change-Id: I28a08abdb1be65a8746702ad304282de4e1100d7
Reviewed-by: Liang Qi <liang.qi@qt.io>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit 567da5e3e0070b7a0dd9ba1acbe9347c6cc1d0fe)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/gui/platform/unix/qdesktopunixservices.cpp | 4 ++--
 src/gui/platform/unix/qdesktopunixservices_p.h | 5 ++++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/gui/platform/unix/qdesktopunixservices.cpp b/src/gui/platform/unix/qdesktopunixservices.cpp
index be472414ee5..a4fff9b11ca 100644
--- a/src/gui/platform/unix/qdesktopunixservices.cpp
+++ b/src/gui/platform/unix/qdesktopunixservices.cpp
@@ -397,7 +397,7 @@ QDesktopUnixServices::QDesktopUnixServices()
 
     QDBusPendingCall pendingCall = QDBusConnection::sessionBus().asyncCall(message);
     auto watcher = new QDBusPendingCallWatcher(pendingCall);
-    m_watcherConnection =
+    m_watcher = watcher;
             QObject::connect(watcher, &QDBusPendingCallWatcher::finished, watcher,
                      [this](QDBusPendingCallWatcher *watcher) {
                          watcher->deleteLater();
@@ -412,7 +412,7 @@ QDesktopUnixServices::QDesktopUnixServices()
 QDesktopUnixServices::~QDesktopUnixServices()
 {
 #if QT_CONFIG(dbus)
-    QObject::disconnect(m_watcherConnection);
+    delete m_watcher;
 #endif
 }
 
diff --git a/src/gui/platform/unix/qdesktopunixservices_p.h b/src/gui/platform/unix/qdesktopunixservices_p.h
index f52dc35bbe2..903bd6e6510 100644
--- a/src/gui/platform/unix/qdesktopunixservices_p.h
+++ b/src/gui/platform/unix/qdesktopunixservices_p.h
@@ -16,11 +16,14 @@
 //
 
 #include <qpa/qplatformservices.h>
+
+#include <QtCore/qpointer.h>
 #include <QtCore/QString>
 #include <QtCore/private/qglobal_p.h>
 
 QT_BEGIN_NAMESPACE
 
+class QDBusPendingCallWatcher;
 class QWindow;
 
 class Q_GUI_EXPORT QDesktopUnixServices : public QPlatformServices
@@ -46,7 +49,7 @@ private:
     QString m_webBrowser;
     QString m_documentLauncher;
 #if QT_CONFIG(dbus)
-    QMetaObject::Connection m_watcherConnection;
+    QPointer<QDBusPendingCallWatcher> m_watcher = nullptr;
 #endif
     bool m_hasScreenshotPortalWithColorPicking = false;
 };