Do not add empty traces, they contain no value.
@@ -1036,7 +1036,9 @@ public class MessageBusVisitorSession implements VisitorSession {
params.getControlHandler().onProgress(progress.getToken());
statistics.add(reply.getVisitorStatistics());
params.getControlHandler().onVisitorStatistics(statistics);
+ if ( ! reply.getTrace().getRoot().isEmpty() ) {
trace.getRoot().addChild(reply.getTrace().getRoot());
+ }
if (params.getDynamicallyIncreaseMaxBucketsPerVisitor()
&& (reply.getVisitorStatistics().getDocumentsReturned()
