Unless otherwise provided by special statute, no injunction shall operate until the party obtaining the same shall give an undertaking, with sufficient surety, to be approved by the clerk of the court granting such injunction, in an amount to be fixed by the court or judge allowing the same, to secure the party injured the damages he may sustain, including reasonable attorney's fees, if it be finally decided that the injunction ought not to have been granted.
R.L. 1910, § 4877.