A covenant never to sue is equivalent to a release as is a bond to indemnify a debtor against his own debt. (Orig. Code 1863, § 2802; Code 1868, § 2810; Code 1873, § 2861; Code 1882, § 2861; Civil Code 1895, § 3714; Civil Code 1910, § 4308; Code 1933, § 20-909.)