When at the time of such withdrawal as aforesaid, valid preemption or homestead claims existed upon any lands within the limits of any such grants which afterward were abandoned, and, under the decisions and rulings of the Land Department, were reentered by preemption or homestead claimants who have complied with the laws governing preemption or homestead entries, and shall make the proper proofs required under such laws, such entries shall be deemed valid, and patents shall issue therefor to the person entitled thereto.