CCP 3657     

Art. 3657.  Same; cumulation with petitory action prohibited; conversion into or separate petitory action by defendant

The plaintiff may not cumulate the petitory and the possessory actions in the same suit or plead them in the alternative, and when he does so he waives the possessory action.  If the plaintiff brings the possessory action, and without dismissing it and prior to judgment therein institutes the petitory action, the possessory action is abated.

When, except as provided in Article 3661(1)-(3), the defendant in a possessory action asserts title in himself, in the alternative or otherwise, he thereby converts the suit into a petitory action, and judicially confesses the possession of the plaintiff in the possessory action.

If, before executory judgment in a possessory action, the defendant therein institutes a petitory action in a separate suit against the plaintiff in the possessory action, the plaintiff in the petitory action judicially confesses the possession of the defendant therein.