From fe148dc641395d93712b5694385a3166008650be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tor=20Arne=20Vestb=C3=B8?= <tor.arne.vestbo@qt.io>
Date: Tue, 8 Apr 2025 21:48:55 +0200
Subject: [PATCH] Use QObjCWeakPointer to track QMacKeyValueObserver observed
 object

Otherwise we might run the risk that the observed object dies before
we try to do removeObserver.

Change-Id: I2b54ff32728fc40fd47be2d14070fc43640f81bf
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit b6ffbebbbe75c53f8dd9a7afd97032f7f4fd8f5c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/kernel/qcore_mac_p.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/corelib/kernel/qcore_mac_p.h b/src/corelib/kernel/qcore_mac_p.h
index 2d3d6d9c5c9..473e84a70fd 100644
--- a/src/corelib/kernel/qcore_mac_p.h
+++ b/src/corelib/kernel/qcore_mac_p.h
@@ -408,7 +408,6 @@ public:
     QMacKeyValueObserver() = default;
 
 #if defined( __OBJC__)
-    // Note: QMacKeyValueObserver must not outlive the object observed!
     QMacKeyValueObserver(NSObject *object, NSString *keyPath, Callback callback,
         NSKeyValueObservingOptions options = NSKeyValueObservingOptionNew)
         : object(object), keyPath(keyPath), callback(new Callback(callback))
@@ -436,7 +435,7 @@ public:
 
     void swap(QMacKeyValueObserver &other) noexcept
     {
-        qt_ptr_swap(object, other.object);
+        std::swap(object, other.object);
         qt_ptr_swap(keyPath, other.keyPath);
         callback.swap(other.callback);
     }
@@ -446,7 +445,7 @@ private:
     void addObserver(NSKeyValueObservingOptions options);
 #endif
 
-    NSObject *object = nullptr;
+    QObjCWeakPointer<NSObject> object;
     NSString *keyPath = nullptr;
     std::unique_ptr<Callback> callback;