Can a police officer search the pocket of a jacket that is not being worn?

In People v. Barnes (1983) 141 Cal.App.3d 854, a police officer asked a motorist stopped for a traffic violation for identification and the motorist replied it was in his sock. The officer did not permit the motorist to retrieve the identification from inside his sock, where the officer could not see, but himself placed his hand on the sock and discovered a large kitchen knife and a bottle that contained PCP. The court held there was a sufficient basis for a reasonable suspicion necessary to justify the search. While the officer's actions were described as a "pat-down search," that would seem to be virtually the only means to determine whether an object is secreted in a sock that a person is wearing. The same is not true of the pocket of a jacket that is not being worn. As the court in Barnes recognized, "`[t]he critical question remains, is this the kind of confrontation in which the officer can reasonably believe in the possibility that a weapon may be used against him?'" (Id. at p. 856.)