(2) No suit shall be maintained to set aside, cancel, annul or otherwise affect a patent to lands issued by the United States or this state, or to compel any person claiming or holding under such patent to convey the lands described therein, or any portion of them, to the plaintiff in such suit, or to hold the same in trust for, or to the use and benefit of such plaintiff, or on account of any matter, thing or transaction which was had, done, suffered or transpired prior to the date of such patent, unless such suit is commenced within 10 years from the date of such patent.

(3) This section shall not bar an equitable owner in possession of real property from defending possession by means of the equitable title; and in any action for the recovery of any real property, or the possession thereof, by any person or persons claiming or holding the legal title to the same under such patent against any person or persons in possession of such real property under any equitable title, or having in equity the right to the possession thereof as against the plaintiff in such action, such equitable right of possession may be pleaded by answer in such action, or set up by bill in equity to enjoin such action or execution upon any judgment rendered therein; and the right of such equitable owner to defend possession in such action, or by bill for injunction, shall not be barred by lapse of time while an action for the possession of such real property is not barred.

(4) In a suit upon a new promise, fraud or mistake, the limitation shall only be deemed to commence from the making of the new promise or the discovery of the fraud or mistake.