Debugger: Add more safety net for failing dumper

In case a dumper explicitly reports the presence of children
but fails to extract them, remove the model's desire to
see them by re-setting the 'wantsChildren' hint explicitly
after a full update.

Change-Id: I09d3d3dd67067d22d39f7685b57570ecb42984d2
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/watchhandler.cpp

@@ -1379,6 +1379,13 @@ void WatchHandler::notifyUpdateFinished()
     foreach (auto item, toRemove)
         m_model->destroyItem(item);
 
+    m_model->forAllItems([this](WatchItem *item) {
+        if (item->wantsChildren && isExpandedIName(item->iname)) {
+            m_model->m_engine->showMessage(QString("ADJUSTING CHILD EXPECTATION FOR " + item->iname));
+            item->wantsChildren = false;
+        }
+    });
+
     m_model->m_contentsValid = true;
     updateWatchersWindow();
     m_model->reexpandItems();