How has the joint-defense privilege been interpreted in the context of attorney-client privilege?

Generally, the attorney-client privilege shields certain communications between the attorney and the client. The joint-defense privilege widens this sphere. The most common application of the privilege is when attorneys representing different parties pool their information together. In Hunydee v. United States, 355 F.2d 183 (9th Cir.1965), the joint-defense privilege was interpreted so as to shield statements made in furtherance of a common defense by a defendant in front of his attorney, a codefendant and the codefendant's attorney. Courts and commentators have suggested that the Hunydee reasoning can be extended such that even inter-client communications in the presence of their attorneys are protected. See Matter of Grand Jury Subpoena, supra, 406 F.Supp. at 388.