What is the ruling on one who masturbates while fasting outside of Ramadan, and is he required to make up that fast?

Masturbation is forbidden for both a fasting person and others. If it results in ejaculation, the fast is broken, and a make-up fast is obligatory if the fast was obligatory, such as making up for Ramadan, or a vow, or an expiation. However, if it was a voluntary fast, the preponderant opinion is that making up the fast is recommended, not obligatory, along with the necessity of repenting to Allah.