This time, nothing, because the cop just gave you a warning.
Now he knows you're driving around with a restricted license and isn't likely to give you a second chance.
Next time, plan on getting arrested, having your car towed and impounded (and sold, if it's your second offense), installing a breath alcohol device in your car, paying a couple of thousand dollars in fines and spending a week or so in jail.
Please understand that this is a general discussion of legal principles by a California lawyer and does not create an attorney/client relationship. It's impossible to give detailed, accurate advice based on a few sentences on a website (and you shouldn't provide too much specific information about your legal matter on a public forum like Avvo, anyway). You should always seek advice from an attorney licensed in your jurisdiction who can give you an informed opinion after reviewing all of the relevant information.
I agree with attorney Marshall's answer - I'm confused if you were driving on the restriction, within the restriction why he would give you a warning? Be very careful driving even if you think you are within the restriction.
I agree with the above attorneys. I want to also point out that the consequences to violating your restricted driving privilege will depend on how you got the restricted license in the first place. Most restricted licenses are a result of a DUI, and so violating the restricted license in that scenario will lead to the same penalties that you get for driving on a suspended license following a DUI -- VC 14601.2 -- 10 days jail minimum, a mandatory ignition interlock device being installed, fines, etc. However, if your restricted license is the result of negligent operator hearing, then violating that privilege is the equivalent of driving on a suspended license because of too many points -- VC 14601(a) -- which doesn't carry a mandatory minimum for jail time and doesn't require the ignition interlock device, but still may lead to jail time, fines, etc.
If you just received a warning, there are no adverse consequences. Generally, a restricted license includes driving to, from and in the course of your employment. Certainly, stopping for gas on your way home should be included.