Fix message-box button lifetimes

Signed-off-by: Loren Eteval <loren.eteval@proton.me>

Furious/Qt/QtWidgets.py

@@ -32,6 +32,8 @@ from PySide6 import QtCore
 from PySide6.QtGui import *
 from PySide6.QtWidgets import *
 
+from shiboken6 import isValid
+
 from typing import Union
 
 import functools
@@ -1126,6 +1128,7 @@ class AppQMessageBox(AppQTransientDialog):
         self._standardButtons = self.StandardButton.NoButton
         self._standardButtonMap = {}
         self._buttonRoles = {}
+        self._buttonConnections = {}
         self._defaultButton = None
         self._escapeButton = None
         self._clickedButton = None
@@ -1264,15 +1267,7 @@ class AppQMessageBox(AppQTransientDialog):
         button.setMinimumHeight(34)
         button.setAttribute(QtCore.Qt.WidgetAttribute.WA_LayoutUsesWidgetRect)
 
-        connectWeakly(
-            button.clicked,
-            self,
-            '_handleButtonClicked',
-            sender=button,
-            forwardSender=True,
-        )
-
-        self._buttonRoles[button] = role
+        self._registerButton(button, role)
 
         if standardButton is not None:
             self._standardButtonMap[standardButton] = button
@@ -1281,6 +1276,33 @@ class AppQMessageBox(AppQTransientDialog):
 
         return button
 
+    def _registerButton(self, button, role):
+        """Own exactly one click and destruction connection per attached button."""
+        if button not in self._buttonConnections:
+            self._buttonConnections[button] = (
+                connectWeakly(
+                    button.clicked,
+                    self,
+                    '_handleButtonClicked',
+                    sender=button,
+                    forwardSender=True,
+                ),
+                connectWeakly(
+                    button.destroyed,
+                    self,
+                    '_removeDestroyedButtons',
+                    sender=button,
+                ),
+            )
+
+        self._buttonRoles[button] = role
+
+    def _removeDestroyedButtons(self):
+        """Release registrations even while an invalid Python wrapper survives."""
+        for button in tuple(self._buttonRoles):
+            if not isValid(button):
+                self.removeButton(button)
+
     def _rebuildButtonLayout(self):
         """Lay out actions with Fluent-style margins and equal stretch."""
         while self.buttonLayout.count():
@@ -1529,15 +1551,7 @@ class AppQMessageBox(AppQTransientDialog):
             customButton.setParent(self.buttonFrame)
             customButton.setAttribute(QtCore.Qt.WidgetAttribute.WA_LayoutUsesWidgetRect)
 
-            connectWeakly(
-                customButton.clicked,
-                self,
-                '_handleButtonClicked',
-                sender=customButton,
-                forwardSender=True,
-            )
-
-            self._buttonRoles[customButton] = role
+            self._registerButton(customButton, role)
             self._rebuildButtonLayout()
 
             return customButton
@@ -1555,14 +1569,31 @@ class AppQMessageBox(AppQTransientDialog):
 
     def removeButton(self, button):
         """Remove one custom or standard button."""
-        self._buttonRoles.pop(button, None)
+        if button not in self._buttonRoles:
+            return
+
+        self._buttonRoles.pop(button)
+
+        for connection in self._buttonConnections.pop(button):
+            QtCore.QObject.disconnect(connection)
+
+        if self._defaultButton is button:
+            self._defaultButton = None
+
+        if self._escapeButton is button:
+            self._escapeButton = None
+
+        if self._clickedButton is button:
+            self._clickedButton = None
 
         for standardButton, candidate in tuple(self._standardButtonMap.items()):
             if candidate is button:
                 self._standardButtons &= ~standardButton
                 self._standardButtonMap.pop(standardButton, None)
 
+        if isValid(button):
             button.setParent(None)
+
         self._rebuildButtonLayout()
 
     def buttons(self):
@@ -1646,6 +1677,10 @@ class AppQMessageBox(AppQTransientDialog):
         finally:
             self._handlingButton = False
 
+        # A button listener may synchronously destroy this box or its parent.
+        if not isValid(self):
+            return
+
         standardButton = self.standardButton(button)
 
         if standardButton != self.StandardButton.NoButton:

tests/test_qt_lifetime.py

@@ -63,9 +63,9 @@ from Furious.Widget.ServerTableView import DeleteServersProgressDialog
 
 from PySide6 import QtCore
 from PySide6.QtGui import QImage
-from PySide6.QtWidgets import QWidget
+from PySide6.QtWidgets import QPushButton, QWidget
 
-from shiboken6 import isValid
+from shiboken6 import isValid, delete as deleteQObject
 
 from tests.support import (
     application,
@@ -149,6 +149,102 @@ class DelayedReceiver(QtCore.QObject):
 class QtLifetimeTest(unittest.TestCase):
     """Stress direct destruction evidence without relying on process RSS alone."""
 
+    def testRemovedMessageBoxButtonDisconnectsAndCanBeReused(self):
+        """Detaching a button ends only the box-owned signal and role lifetime."""
+        application()
+        with isolatedSettings():
+            box = AppQMessageBox()
+            button = QPushButton('Reusable button')
+            finished = []
+            externalClicks = []
+            box.finished.connect(finished.append)
+            button.clicked.connect(lambda: externalClicks.append(True))
+            try:
+                for _ in range(30):
+                    box.addButton(button, box.ButtonRole.AcceptRole)
+                    box.setDefaultButton(button)
+                    box.setEscapeButton(button)
+                    box.removeButton(button)
+                    button.click()
+                    self.assertEqual(finished, [])
+                    self.assertIsNone(box.defaultButton())
+                    self.assertIsNone(box.escapeButton())
+                    self.assertIsNone(button.parent())
+                    self.assertEqual(button.receivers(QtCore.SIGNAL('clicked()')), 1)
+
+                self.assertEqual(len(externalClicks), 30)
+                box.addButton(button, box.ButtonRole.AcceptRole)
+                box.addButton(button, box.ButtonRole.AcceptRole)
+                box.open()
+                button.click()
+                processQtEvents()
+                self.assertEqual(finished, [int(AppQDialog.DialogCode.Accepted)])
+                self.assertFalse(isValid(box))
+                self.assertFalse(isValid(button))
+            finally:
+                if isValid(box):
+                    deleteQObject(box)
+                if isValid(button):
+                    deleteQObject(button)
+                processQtEvents()
+
+    def testReplacingMessageBoxButtonsReleasesOldDefaultAndEscape(self):
+        """A retained dialog must not retain removed standard-button wrappers."""
+        application()
+        with isolatedSettings():
+            box = AppQMessageBox()
+            references = []
+            try:
+                for _ in range(30):
+                    box.setStandardButtons(box.StandardButton.Yes)
+                    button = box.button(box.StandardButton.Yes)
+                    references.append(weakref.ref(button))
+                    box.setDefaultButton(button)
+                    box.setEscapeButton(button)
+                    box.setStandardButtons(box.StandardButton.No)
+                    del button
+                    processQtEvents()
+                    self.assertIsNone(box.defaultButton())
+                    self.assertIsNone(box.escapeButton())
+                self.assertTrue(all(reference() is None for reference in references))
+            finally:
+                deleteQObject(box)
+                processQtEvents()
+
+    def testNativeButtonDestructionRemovesMessageBoxRegistrations(self):
+        """Deleting an attached button cannot leave invalid wrapper roles behind."""
+        application()
+        with isolatedSettings():
+            box = AppQMessageBox()
+            try:
+                for _ in range(30):
+                    button = box.addButton(box.StandardButton.Yes)
+                    box.setDefaultButton(button)
+                    box.setEscapeButton(button)
+                    deleteQObject(button)
+                    self.assertEqual(box.buttons(), [])
+                    self.assertIsNone(box.defaultButton())
+                    self.assertIsNone(box.escapeButton())
+                    self.assertIsNone(box.button(box.StandardButton.Yes))
+            finally:
+                deleteQObject(box)
+                processQtEvents()
+
+    def testMessageBoxCallbackMayDestroyItsOwner(self):
+        """Button activation cannot finish a box destroyed by its own listener."""
+        application()
+        with isolatedSettings():
+            owner = QWidget()
+            box = AppQMessageBox(parent=owner)
+            button = box.addButton(box.StandardButton.Yes)
+            box.buttonClicked.connect(lambda *_args: deleteQObject(owner))
+            with mock.patch('sys.excepthook') as exceptionHook:
+                button.click()
+                processQtEvents()
+            exceptionHook.assert_not_called()
+            self.assertFalse(isValid(box))
+            self.assertFalse(isValid(button))
+
     def testRoutingDocumentationDoesNotEnterCompiledMethodProtection(self):
         """Closing routing editors releases labels under Nuitka-style retention."""
         originalConnect = QtCore.SignalInstance.connect