Solved a bug when saving the xodr file: the information from the previous...

Solved a bug when saving the xodr file: the information from the previous signal or object was concatenated to the new one.

OpenRoadEd/OpenDrive/OpenDriveXmlWriter.cpp

@@ -853,6 +853,7 @@ bool OpenDriveXmlWriter::WriteObjects (TiXmlElement *node, Road* road)
     TiXmlElement *object_node = new TiXmlElement("object");
     nodeObjects->LinkEndChild(object_node);
 
+    text.str("");
     text << setprecision(16) << setiosflags (ios_base::scientific) << object->GetS();
     object_node->SetAttribute("s",text.str());
     text.str("");
@@ -920,6 +921,7 @@ bool OpenDriveXmlWriter::WriteSignals (TiXmlElement *node, Road* road)
     TiXmlElement *signal_node = new TiXmlElement("signal");
     nodeSignals->LinkEndChild(signal_node);
 
+    text.str("");
     text << setprecision(16) << setiosflags (ios_base::scientific) << signal->GetS();
     signal_node->SetAttribute("s",text.str());
     text.str("");