Make QMetaObject::Connection check its state deeply

Since Connection can be copied, one copy could be used for
disconnecting, but the other's d_ptr wouldn't get updated and would
continue to report as still connected.

This patch fixes that by making it check the internal state. That is
only done after d_ptr is already known to be non-null. Unfortunately,
that is the common path:

  if (connect(sender, &Sender::signal, [] {}))

will call an out-of-line function. I don't see a way out.

Task-number: QTBUG-46213
Change-Id: I66a35ce5f88941f29aa6ffff13dfb45dca68a350
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
index 3ec84b5198..4617ce5e74 100644
--- a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
+++ b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
@@ -918,6 +918,8 @@ void tst_QObject::connectDisconnectNotifyPMF()
     QMetaObject::Connection conn = connect((SenderObject*)s, &SenderObject::signal1,
                                            (ReceiverObject*)r, &ReceiverObject::slot1);
 
+    QVERIFY(conn);
+
     // Test disconnectNotify when disconnecting by QMetaObject::Connection
     QVERIFY(QObject::disconnect(conn));
     // disconnectNotify() is not called, but it probably should be.
@@ -5751,7 +5753,6 @@ void tst_QObject::connectFunctorWithContext()
 {
     int status = 1;
     SenderObject obj;
-    QMetaObject::Connection handle;
     ContextObject *context = new ContextObject;
     QEventLoop e;
 
@@ -6058,8 +6059,12 @@ void tst_QObject::disconnectDoesNotLeakFunctor()
             QVERIFY(c2);
             QCOMPARE(countedStructObjectsCount, 2);
             QVERIFY(QObject::disconnect(c1));
+            QVERIFY(!c1);
+            QVERIFY(!c2);
             // functor object has been destroyed
             QCOMPARE(countedStructObjectsCount, 1);
+            QVERIFY(!QObject::disconnect(c2));
+            QCOMPARE(countedStructObjectsCount, 1);
         }
         QCOMPARE(countedStructObjectsCount, 0);
     }