The court is hereby granted large discretion and far reaching powers in the matter of establishing and fixing the validity of land patents issued by the state and title conveyed thereunder, and the sound discretion of the court in deciding all such cases shall be the controlling factor in settling the issues where only state interests are involved. No decree pro confesso shall be taken against the state, but on failure of the attorney general to answer within the time required by law, the cause shall be heard on the bill and proof thereon.