A plea to an indictment, on the ground that the grand jurors by whom it was found were not drawn in the presence of the officers designated by law must, if the accused has been arrested, be filed at the session at which the indictment is found, and, if the accused has not been arrested, it must be filed at the first session at which it is practicable after the defendant's arrest; and, in all cases before a plea to the merits, if sustained, the defendant must not be discharged but must be held in custody or bailed, as the case may be, to answer another indictment at the same or the next session of the court, and the time elapsing between the first and second indictments, in such case, must not be computed as a part of the period limited by law for the prosecution of the offense.