I dissent. Mandate will issue against a public officer "to compel the performance of an act which the law specially enjoins, as a duty resulting from an office." (Code Civ. Proc., sec. 1085.) It is not the duty of a public officer to admit to a subordinate public office one who has no right to occupy such office. Under the terms of the Oakland charter the petitioner, by taking an indefinite leave of absence from his civil service position of captain of inspectors of the police department and by accepting the incompatible position of chief of police, relinquished his civil service standing in the former position. The office of captain of inspectors is governed by the civil *Page 437 service provisions of the charter. It is filled by examination, certification, and promotion. The office of chief of police is noncivil service. That one person cannot occupy both offices goes without question. That petitioner could not occupy one and keep a string on the other is equally clear, because the charter specifically limits the period of leaves of absence from the civil service positions and defines the purposes for which they may be granted. When petitioner accepted the position of chief of police the office of captain of inspectors became vacant and should have been filled by the one whose civil service standing entitled him to the appointment. Such person, whoever he may be, still has the legal right to such office. It is alleged in the petition, and not controverted, that another now occupies such office, and it is to be presumed that he is the one who is legally entitled to possession.
The situation is not changed by the action of the city officials in recognizing petitioner as captain of inspectors after he returned to that office. Estoppel does not run against the city in a case of this kind. That is to say, none of the city officials could defeat the plain provisions of the charter merely by failing to object to the unlawful occupancy of the office by petitioner or by recognizing him for a time as such.
Such being the case, the special defense interposed by respondents to the effect that petitioner was not entitled to be restored because he had voluntarily relinquished his civil service standing demands a denial of the writ prayed for.
The effect of the majority opinion is that when a petitioner seeks mandate against a public official, assigning certain reasons why he has been denied the right which he claims, such official may defend only upon such grounds as are laid out for him by the petitioner. With this rule I do not agree.
In this case no duty rests upon respondents to admit petitioner to the office of captain of inspectors unless he is entitled to occupy it. If his title is disputed and that cannot be tried by mandamus, then he, too, should proceed by quowarranto, as the majority opinion holds must be done by one who questions that title. If the question of title is merely incidental to the relief sought, then it may be tried in this case. (Bannerman v. Boyle, 160 Cal. 197, 203, *Page 438 [116 P. 732].) Petitioner has put his title in issue. Respondents have controverted it. The facts are undisputed and the law is not questioned. The petition should be denied.
A petition for a rehearing of this cause was denied by the district court of appeal on July 26, 1920, and a petition to have the cause heard in the supreme court, after judgment in the district court of appeal, was denied by the supreme court on September 2, 1920.
All the Justices concurred except Shaw, J., Wilbur, J., and Sloane, J., who were absent.