If, upon calculation of the value of advantages thus given, and of the other effects remaining in the succession, such remaining part should prove insufficient to give to the other children their legitimate portion, the donee would then be obliged to collate the sum by him received, as far as necessary to complete such portion, though he would wish to keep the donation, and renounce the inheritance; and in this calculation of the legitimate portion, the property given or bequeathed by the ascendants, not only to their children, but even to all other persons, whether relations or strangers, must be included.