- std::vector<TopoDS_Wire> aTCurves;
- GetWires(aToolPolyline, aTCurves);
- append( aToolCurves, aTCurves);
+ if (!aToolPolyline.IsNull())
+ {
+ std::vector<TopoDS_Wire> aTCurves;
+ GetWires(aToolPolyline, aTCurves);
+ append( aToolCurves, aTCurves);
+ }