QObject: fix crash when deleteing the receiver object withing a DirectConncetion involving two threads.

We did not set the sender(), but we tried to reset it anyway.

Task-number: QTBUG-7935
Reviewed-by: Brad

2 files changed, 30 insertions, 7 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 5298fff..689e44c 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -3264,12 +3264,14 @@ void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_sign
 
             const int method = c->method;
             QObjectPrivate::Sender currentSender;
-            currentSender.sender = sender;
-            currentSender.signal = signal_absolute_index;
-            currentSender.ref = 1;
+            const bool receiverInSameThread = currentThreadData == receiver->d_func()->threadData;
             QObjectPrivate::Sender *previousSender = 0;
-            if (currentThreadData == receiver->d_func()->threadData)
+            if (receiverInSameThread) {
+                currentSender.sender = sender;
+                currentSender.signal = signal_absolute_index;
+                currentSender.ref = 1;
                 previousSender = QObjectPrivate::setCurrentSender(receiver, &currentSender);
+            }
             locker.unlock();
 
             if (qt_signal_spy_callback_set.slot_begin_callback != 0) {
@@ -3285,8 +3287,8 @@ void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_sign
                 metacall(receiver, QMetaObject::InvokeMetaMethod, method, argv ? argv : empty_argv);
             } QT_CATCH(...) {
                 locker.relock();
-
-                QObjectPrivate::resetCurrentSender(receiver, &currentSender, previousSender);
+                if (receiverInSameThread)
+                    QObjectPrivate::resetCurrentSender(receiver, &currentSender, previousSender);
 
                 --connectionLists->inUse;
                 Q_ASSERT(connectionLists->inUse >= 0);
@@ -3301,7 +3303,8 @@ void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_sign
 
             locker.relock();
 
-            QObjectPrivate::resetCurrentSender(receiver, &currentSender, previousSender);
+            if (receiverInSameThread)
+                QObjectPrivate::resetCurrentSender(receiver, &currentSender, previousSender);
 
             if (connectionLists->orphaned)
                 break;
diff --git a/tests/auto/qobject/tst_qobject.cpp b/tests/auto/qobject/tst_qobject.cpp
index 4fa6aaa..985dfa4 100644
--- a/tests/auto/qobject/tst_qobject.cpp
+++ b/tests/auto/qobject/tst_qobject.cpp
@@ -2647,6 +2647,16 @@ void tst_QObject::installEventFilter()
     QVERIFY(spy.eventList().isEmpty());
 }
 
+class EmitThread : public QThread
+{   Q_OBJECT
+public:
+    void run(void) {
+        emit work();
+    }
+signals:
+    void work();
+};
+
 class DeleteObject : public QObject
 {
     Q_OBJECT
@@ -2712,6 +2722,16 @@ void tst_QObject::deleteSelfInSlot()
 
         QVERIFY(thread.wait(10000));
     }
+
+    {
+        EmitThread sender;
+        DeleteObject *receiver = new DeleteObject();
+        connect(&sender, SIGNAL(work()), receiver, SLOT(deleteSelf()), Qt::DirectConnection);
+        QPointer<DeleteObject> p = receiver;
+        sender.start();
+        QVERIFY(sender.wait(10000));
+        QVERIFY(p.isNull());
+    }
 }
 
 class DisconnectObject : public QObject