All actions and proceedings pending in the district court of any county at the time any judicial district is abolished and a new district established under the provisions of this act*, whether the issues are joined or not, shall proceed in the district court of the judicial district in which said county is placed by the provisions of this act in the same manner as if said actions and proceedings had been commenced in said district, except when an action or proceeding pending in such a district court has been tried by the judge of said court, and by him taken under advisement, and is still undecided at the time the judicial district is established, then it shall be the duty of the judge who tried said cause to make and render his findings and judgment thereon, and to determine all motions therein in all respects as though said county had not been placed in such judicial district.