People v. Johnson (1978) 82 Cal. App. 3d 183 [147 Cal. Rptr. 55] was the first case to affirm the authority of the trial court to require a defendant to waive the custody credit provisions of section 2900.5. The defendant in Johnson had been placed on probation on condition that he serve one year in jail. He served the jail time and then violated probation. The defendant requested continued probation with additional jail time. the court thought it had no authority to grant the request because section 19a (now 19.2) limited jail time as a condition of probation to one year, and section 2900.5 required that the defendant be credited for all days in custody. As the Court of Appeal observed: "The net result of these two legislative efforts is that if a defendant has served a year in jail as a condition of probation, a violation means either a prison sentence or a fatherly (or motherly) lecture on the evils of crime." (82 Cal. App. 3d at p. 185.) After reviewing the legislative history of the provisions and finding that they were enacted for the benefit of the prisoners, the court determined that they could be waived by the defendant: "Thus, we conclude that where a defendant who has spent a year in the county jail as a condition of probation subsequently commits a probation violation, the sentencing judge should not be forced to choose between ignoring the violation or imposing sentence to state prison. The court should be free to choose either of these options in the exercise of its discretion but it should also have the power, with the consent of the defendant, to fashion an intermediate disposition by modifying probation to provide for additional time up to one year in jail." (Id. at p. 188.)