libpyside: Clean up lambdas connected to signals earlier in shutdown

Run a signal handler cleanup in CoreApplication::aboutToQuit() already
before the general cleanup. This prevents them from leaking out of a
main() function, for example.

Task-number: PYSIDE-2646
Pick-to: 6.5
Change-Id: I87cce8d131c40c02b44b0102b3774477676b8f89
Reviewed-by: Christian Tismer <tismer@stackless.com>
(cherry picked from commit 47d6abbd727d193158cdc1747cb18241267409c1)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 16bedacb16dd52a7a3d6a09fca8623aaaa965c70)

2 files changed, 21 insertions, 1 deletions

diff --git a/sources/pyside6/libpyside/signalmanager.cpp b/sources/pyside6/libpyside/signalmanager.cpp
index b46761284..bb3453bad 100644
--- a/sources/pyside6/libpyside/signalmanager.cpp
+++ b/sources/pyside6/libpyside/signalmanager.cpp
@@ -21,6 +21,7 @@
 #include <sbkstaticstrings.h>
 #include <sbkerrors.h>
 
+#include <QtCore/QCoreApplication>
 #include <QtCore/QByteArrayView>
 #include <QtCore/QDebug>
 #include <QtCore/QHash>
@@ -311,8 +312,21 @@ void SignalManager::setQmlMetaCallErrorHandler(QmlMetaCallErrorHandler handler)
     SignalManagerPrivate::m_qmlMetaCallErrorHandler = handler;
 }
 
+static void qAppAboutToQuit()
+{
+    SignalManager::instance().purgeEmptyGlobalReceivers();
+}
+
 QObject *SignalManager::globalReceiver(QObject *sender, PyObject *callback, QObject *receiver)
 {
+    static bool registerQuitHandler =  true;
+    if (registerQuitHandler) {
+        if (auto *app = QCoreApplication::instance()) {
+            registerQuitHandler = false;
+            QObject::connect(app, &QCoreApplication::aboutToQuit, qAppAboutToQuit);
+        }
+    }
+
     auto &globalReceivers = m_d->m_globalReceivers;
     const GlobalReceiverKey key = GlobalReceiverV2::key(callback);
     auto it = globalReceivers.find(key);
@@ -326,10 +340,15 @@ QObject *SignalManager::globalReceiver(QObject *sender, PyObject *callback, QObj
     return it.value().get();
 }
 
+void SignalManager::purgeEmptyGlobalReceivers()
+{
+    m_d->purgeEmptyGlobalReceivers();
+}
+
 void SignalManager::notifyGlobalReceiver(QObject *receiver)
 {
     reinterpret_cast<GlobalReceiverV2 *>(receiver)->notify();
-    m_d->purgeEmptyGlobalReceivers();
+    purgeEmptyGlobalReceivers();
 }
 
 void SignalManager::releaseGlobalReceiver(const QObject *source, QObject *receiver)
diff --git a/sources/pyside6/libpyside/signalmanager.h b/sources/pyside6/libpyside/signalmanager.h
index 684a4e5e7..c531d6630 100644
--- a/sources/pyside6/libpyside/signalmanager.h
+++ b/sources/pyside6/libpyside/signalmanager.h
@@ -78,6 +78,7 @@ public:
 
     // Disconnect all signals managed by Globalreceiver
     void clear();
+    void purgeEmptyGlobalReceivers();
 
     // Utility function to call a python method usign args received in qt_metacall
     static int callPythonMetaMethod(const QMetaMethod& method, void** args, PyObject* obj, bool isShortCuit);