(1) No presiding officer or member of a court-martial, no judge advocate, no party to any proceeding before a court-martial, or his legal practitioner or agent, and no witness acting in obedience to a summons to attend a court-martial shall, while proceeding to, attending or returning from, a court-martial, be liable to arrest under civil or revenue process.
     (2) If any such person is arrested under any such process, he may be discharged by order of the courtmartial.