Any such corporate authorities, or judge, holding the title to any such lands in trust, as declared in said acts of congress, must, by a good and sufficient conveyance, grant and convey the title to each and every block, lot, share or parcel of the same to the person entitled thereto, according to his rights or interest in the same as they exist, in law or equity, at the time of the entry of such lands, and when any parcel or share of such lands is occupied or possessed by one or more persons, claiming the same by grant, lease or sale, the respective rights and interests of such persons, in relation to each other in the same, are not changed or impaired by any such conveyance. Every conveyance, by such corporate authorities or judge, pursuant to the provisions of this chapter, must be executed and acknowledged as to admit the same to be recorded, and if made previous to the issuing of the patent for such lands, it must contain a covenant that the grantor will, after the issuing of such patent, execute, acknowledge and deliver to the grantee, his heirs or assigns, such further conveyance as may be or become necessary to fully vest and perfect the title to the lands therein described in the grantee, his heirs or assigns.