3 files changed, 82 insertions, 41 deletions
diff --git a/sources/pyside6/libpyside/dynamicslot.cpp b/sources/pyside6/libpyside/dynamicslot.cpp
index cc6d50d82..3d9b9c1be 100644
--- a/sources/pyside6/libpyside/dynamicslot.cpp
+++ b/sources/pyside6/libpyside/dynamicslot.cpp
@@ -134,41 +134,8 @@ void MethodDynamicSlot::formatDebug(QDebug &debug) const
         << ", function=" << PySide::debugPyObject(m_function) << ')';
 }
 
-// Store a weak reference on pythonSelf.
-class TrackingMethodDynamicSlot : public MethodDynamicSlot
-{
-    Q_DISABLE_COPY_MOVE(TrackingMethodDynamicSlot)
-public:
-    explicit TrackingMethodDynamicSlot(PyObject *function, PyObject *pythonSelf,
-                                       PyObject *weakRef);
-    ~TrackingMethodDynamicSlot() override;
-
-    void releaseWeakRef() { m_weakRef = nullptr; }
-
-private:
-    PyObject *m_weakRef;
-};
-
-TrackingMethodDynamicSlot::TrackingMethodDynamicSlot(PyObject *function, PyObject *pythonSelf,
-                                                     PyObject *weakRef) :
-    MethodDynamicSlot(function, pythonSelf),
-    m_weakRef(weakRef)
-{
-}
-
-TrackingMethodDynamicSlot::~TrackingMethodDynamicSlot()
-{
-    if (m_weakRef != nullptr) {
-        Shiboken::GilState gil;
-        // weakrefs must not be de-refed after the object has been deleted,
-        // else they get negative refcounts.
-        if (PepExt_Weakref_IsAlive(m_weakRef))
-            Py_DECREF(m_weakRef);
-    }
-}
-
 // Delete the connection on receiver deletion by weakref
-class PysideReceiverMethodSlot : public TrackingMethodDynamicSlot
+class PysideReceiverMethodSlot : public MethodDynamicSlot
 {
     Q_DISABLE_COPY_MOVE(PysideReceiverMethodSlot)
 public:
@@ -179,19 +146,21 @@ public:
 
 static void onPysideReceiverSlotDestroyed(void *data)
 {
-    auto *self = reinterpret_cast<PysideReceiverMethodSlot *>(data);
-    // Ensure the weakref is gone in case the connection stored in
-    // Qt's internals outlives Python.
-    self->releaseWeakRef();
+    auto *pythonSelf = reinterpret_cast<PyObject *>(data);
     Py_BEGIN_ALLOW_THREADS
-    disconnectReceiver(self->pythonSelf());
+    disconnectReceiver(pythonSelf);
     Py_END_ALLOW_THREADS
 }
 
 PysideReceiverMethodSlot::PysideReceiverMethodSlot(PyObject *function, PyObject *pythonSelf) :
-    TrackingMethodDynamicSlot(function, pythonSelf,
-                              WeakRef::create(pythonSelf, onPysideReceiverSlotDestroyed, this))
+    MethodDynamicSlot(function, pythonSelf)
 {
+    // PYSIDE-3148: The weakref is automatically deleted when the notification triggers.
+    // Note that notifications may trigger after deletion of TrackingMethodDynamicSlot in case
+    // of multiple connections to the same receiver, so, &DynamicSlot must not be used as user
+    // data. Also trying to actively deref a pending weak ref from ~TrackingMethodDynamicSlot()
+    // does not reliably prevent the notification from being triggered.
+    WeakRef::create(pythonSelf, onPysideReceiverSlotDestroyed, pythonSelf);
 }
 
 DynamicSlot* DynamicSlot::create(PyObject *callback)
diff --git a/sources/pyside6/tests/signals/CMakeLists.txt b/sources/pyside6/tests/signals/CMakeLists.txt
index dd8f4a016..094caaaf6 100644
--- a/sources/pyside6/tests/signals/CMakeLists.txt
+++ b/sources/pyside6/tests/signals/CMakeLists.txt
@@ -21,6 +21,7 @@ PYSIDE_TEST(qobject_callable_connect_test.py)
 PYSIDE_TEST(qobject_destroyed_test.py)
 PYSIDE_TEST(qobject_receivers_test.py)
 PYSIDE_TEST(qobject_sender_test.py)
+PYSIDE_TEST(nonqobject_receivers_test.py)
 PYSIDE_TEST(ref01_test.py)
 PYSIDE_TEST(ref02_test.py)
 PYSIDE_TEST(ref03_test.py)
diff --git a/sources/pyside6/tests/signals/nonqobject_receivers_test.py b/sources/pyside6/tests/signals/nonqobject_receivers_test.py
new file mode 100644
index 000000000..4bb47e5df
--- /dev/null
+++ b/sources/pyside6/tests/signals/nonqobject_receivers_test.py
@@ -0,0 +1,71 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+'''Test case for non-QObject.receivers'''
+
+import os
+import sys
+import unittest
+
+from pathlib import Path
+sys.path.append(os.fspath(Path(__file__).resolve().parents[1]))
+from init_paths import init_test_paths  # noqa: F401
+init_test_paths(False)
+
+from helper.usesqapplication import UsesQApplication  # noqa: F401
+
+from PySide6.QtGui import QAction  # noqa: F401
+
+
+receiver_instances = 0
+
+
+class Receiver:
+
+    def __init__(self):
+        global receiver_instances
+        receiver_instances += 1
+        self.slot1Triggered = 0
+        self.slot2Triggered = 0
+
+    def __del__(self):
+        global receiver_instances
+        receiver_instances -= 1
+
+    def slot1(self):
+        self.slot1Triggered += 1
+
+    def slot2(self):
+        self.slot2Triggered += 1
+
+
+class TestQObjectReceivers(UsesQApplication):
+    '''Test case for non-QObject.receivers'''
+
+    @unittest.skipUnless(hasattr(sys, "getrefcount"), f"{sys.implementation.name} has no refcount")
+    def testBasic(self):
+        '''The test verifies that connections to methods of a non-QObject work
+           (TrackingMethodDynamicSlot). Also, despite being stored in the signal manager,
+           making connections should not increase references on the receiver or prevent
+           the receivers from being deleted, which is achieved using weak reference
+           tracking notifications.
+           2 connections are used to trigger a corruption caused by multiple weak reference
+           notifications (PYSIDE-3148).'''
+        action1 = QAction("a1", qApp)  # noqa: F821
+        action2 = QAction("a2", qApp)  # noqa: F821
+        receiver = Receiver()
+        self.assertEqual(receiver_instances, 1)
+        base_ref_count = sys.getrefcount(receiver)
+        action1.triggered.connect(receiver.slot1)
+        action2.triggered.connect(receiver.slot2)
+        self.assertEqual(sys.getrefcount(receiver), base_ref_count)
+        action1.trigger()
+        action2.trigger()
+        self.assertEqual(receiver.slot1Triggered, 1)
+        self.assertEqual(receiver.slot2Triggered, 1)
+        receiver = 0
+        self.assertEqual(receiver_instances, 0)
+
+
+if __name__ == '__main__':
+    unittest.main()