DAGNode: fixing traversal when a visitor is run from a node with a not up-to-date descendancy.
DAGNode: fixing traversal when a visitor is run from a node with a not up-to-date descendancy.

Former-commit-id: 6eef0ed3e9baf1eb8893e1ce5ef326dd45f7a909
Anatoscope/sofa,FabienPean/sofa,Anatoscope/sofa,Anatoscope/sofa,Anatoscope/sofa,FabienPean/sofa,hdeling/sofa,hdeling/sofa,Anatoscope/sofa,hdeling/sofa,Anatoscope/sofa,FabienPean/sofa,hdeling/sofa,hdeling/sofa,FabienPean/sofa,Anatoscope/sofa,Anatoscope/sofa,hdeling/sofa,FabienPean/sofa,hdeling/sofa,FabienPean/sofa,Anatoscope/sofa,FabienPean/sofa,FabienPean/sofa,hdeling/sofa,hdeling/sofa,hdeling/sofa,FabienPean/sofa,FabienPean/sofa