diff -r e24348a560a6 -r b72c6db6890b src/dbus/qdbusintegrator.cpp
--- a/src/dbus/qdbusintegrator.cpp	Fri Jun 11 14:24:45 2010 +0300
+++ b/src/dbus/qdbusintegrator.cpp	Wed Jun 23 19:07:03 2010 +0300
@@ -523,7 +523,7 @@
         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 
     QDBusMessage amsg = QDBusMessagePrivate::fromDBusMessage(message);
-    qDBusDebug() << d << "got message:" << amsg;
+    qDBusDebug() << d << "got message (signal):" << amsg;
 
     return d->handleMessage(amsg) ?
         DBUS_HANDLER_RESULT_HANDLED :
@@ -1687,15 +1687,31 @@
 void QDBusConnectionPrivate::waitForFinished(QDBusPendingCallPrivate *pcall)
 {
     Q_ASSERT(pcall->pending);
-    QDBusDispatchLocker locker(PendingCallBlockAction, this);
-    q_dbus_pending_call_block(pcall->pending);
-    // QDBusConnectionPrivate::processFinishedCall() is called automatically
+    Q_ASSERT(!pcall->autoDelete);
+    //Q_ASSERT(pcall->mutex.isLocked()); // there's no such function
+
+    if (pcall->waitingForFinished) {
+        // another thread is already waiting
+        pcall->waitForFinishedCondition.wait(&pcall->mutex);
+    } else {
+        pcall->waitingForFinished = true;
+        pcall->mutex.unlock();
+
+        {
+            QDBusDispatchLocker locker(PendingCallBlockAction, this);
+            q_dbus_pending_call_block(pcall->pending);
+            // QDBusConnectionPrivate::processFinishedCall() is called automatically
+        }
+        pcall->mutex.lock();
+    }
 }
 
 void QDBusConnectionPrivate::processFinishedCall(QDBusPendingCallPrivate *call)
 {
     QDBusConnectionPrivate *connection = const_cast<QDBusConnectionPrivate *>(call->connection);
 
+    QMutexLocker locker(&call->mutex);
+
     QDBusMessage &msg = call->replyMessage;
     if (call->pending) {
         // decode the message
@@ -1725,6 +1741,12 @@
             qDBusDebug() << "Deliver failed!";
     }
 
+    if (call->pending)
+        q_dbus_pending_call_unref(call->pending);
+    call->pending = 0;
+
+    locker.unlock();
+
     // Are there any watchers?
     if (call->watcherHelper)
         call->watcherHelper->emitSignals(msg, call->sentMessage);
@@ -1732,12 +1754,10 @@
     if (msg.type() == QDBusMessage::ErrorMessage)
         emit connection->callWithCallbackFailed(QDBusError(msg), call->sentMessage);
 
-    if (call->pending)
-        q_dbus_pending_call_unref(call->pending);
-    call->pending = 0;
-
-    if (call->autoDelete)
+    if (call->autoDelete) {
+        Q_ASSERT(!call->waitingForFinished); // can't wait on a call with autoDelete!
         delete call;
+    }
 }
 
 int QDBusConnectionPrivate::send(const QDBusMessage& message)
@@ -1879,17 +1899,14 @@
 {
     if (isServiceRegisteredByThread(message.service())) {
         // special case for local calls
-        QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate;
-        pcall->sentMessage = message;
+        QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate(message, this);
         pcall->replyMessage = sendWithReplyLocal(message);
-        pcall->connection = this;
 
         return pcall;
     }
 
     checkThread();
-    QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate;
-    pcall->sentMessage = message;
+    QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate(message, this);
     pcall->ref = 0;
 
     QDBusError error;
@@ -1913,7 +1930,6 @@
             q_dbus_message_unref(msg);
 
             pcall->pending = pending;
-            pcall->connection = this;
             q_dbus_pending_call_set_notify(pending, qDBusResultReceived, pcall, 0);
 
             return pcall;