Change handling of N=1
Fixes #21865 (closed) - How to handle N=1
Old code failed an assert when trying to process the "factor" of 1
Prochaines maintenances programmées: lundi 06/05, lundi 03/06, lundi 01/07
Pour plus d'informations: https://doc-si.inria.fr/display/SU/Gitlab
Fixes #21865 (closed) - How to handle N=1
Old code failed an assert when trying to process the "factor" of 1