What is the effect of disclosing the name of an informer in a criminal proceeding?

The People's reliance upon People v. Hammond, 54 Cal.2d 846, 851--852, 9 Cal.Rptr. 233, 357 P.2d 289, is misplaced. In Hammond the name of the informer was disclosed to defendant at a preliminary hearing stage of the proceeding but his intervening death foreclosed his being called as a witness. The court, after concluding that the value of the informer's testimony was problematical, held the delay in being furnished the name was initiated by defendant and therefore such was not a basis for complaint. Hammond did not involve a second trial after an erroneous refusal to [35 Cal.App.3d 28] disclose and for that and other reasons is factually distinguishable and not controlling of our decision herein.