Whenever a temporary vacancy has been found to exist under s. 17.025 and the certificate of temporary incapacity filed in the office of the secretary of state remains in effect, the affected incumbent shall continue to be entitled to receive the incumbent’s full salary, and employer-paid fringe benefits, during the period of the temporary vacancy but not beyond the expiration of the incumbent’s term. The person selected or qualified under s. 17.025 (4) to replace the incumbent during the temporary vacancy shall be reimbursed for the actual and necessary expenses incurred in the performance of duties as temporary successor and shall as compensation for those services be entitled to receive a sum equal to the amount of salary the disabled incumbent receives during the temporary vacancy, but if the person serving as temporary successor is already a salaried officer or employee of this state, the amount payable to the temporary successor, in addition to the temporary successor’s regular salary, shall be the difference between the temporary successor’s regular salary and the salary of the incumbent in the position in which the temporary vacancy exists. Nothing in this section shall authorize a reduction in the salary of a state officer or employee appointed to fill a temporary vacancy.