Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Donatist Controversy.: Chapter 33

Chapter 33.—64.  Donatulus of Capse 1847 said:  "I also have always entertained this opinion, that heretics, who have gained nothing outside the Church, should be baptized when they are converted to the Church." 1848

65.  To this the answer is:  They have, indeed, gained nothing outside the Church, but that is nothing towards salvation, not nothing towards the sacrament.  For salvation is peculiar to the good; but the sacraments are common to the good and bad alike.

Footnotes

Capse was in ecclesiastical province of Byzacene.  This Donatulus is probably to be identified with the one mentioned Cypr. Ep. lvi.

Conc. Carth. sec. 69.