Can a purchaser at a sale under a deed of trust bring a cross-complaint and affirmative defense in a proceeding in unlawful detainer?

Cheney v. Trauzettel, supra, was a proceeding in unlawful detainer brought under section 1161a of the Code of Civil Procedure by the purchaser at a sale under a deed of trust. The defendants answered and cross-complained, setting up a claim of title and several other defenses, including the pendency of a quiet title suit between the parties involving the same property. The trial court, on motion of the plaintiffs, struck out the cross-complaint and special defenses and gave judgment for the plaintiff. Defendants appealed and in affirming the judgment the court stated, 9 Cal.2d at pages 159-160, 69 P.2d at page 833: 'The trial court properly held that in the summary proceeding in unlawful detainer the right to possession alone was involved, and the broad question of title could not be raised and litigated by cross-complaint or affirmative defense. [Citing cases.] It is true that where the purchaser at a trustee's sale proceeds under section 1161a of the Code of Civil Procedure he must prove his acquisition of title by purchase at the sale; but it is only to this limited extent, as provided by the statute, that the title may be litigated in such a proceeding. [Citing cases.]