It is impossible to enforce an IP agreement if there is a previous agreement already in play. So before anyone of us gets a new job sign an IP agreement with your best friend that includes full access and distribution rights to anything you code for the rest of your life plus a non disclosure clause stating that the terms of the agreement can not be discussed. Then it is the responsibility of the employer to ask you if you are subject to any previous agreements. And if they don't ask you, you can't be held liable for not telling them because your previous agreement prevents you from offering that information to them.
Slashdot Mirror
It is impossible to enforce an IP agreement if there is a previous agreement already in play. So before anyone of us gets a new job sign an IP agreement with your best friend that includes full access and distribution rights to anything you code for the rest of your life plus a non disclosure clause stating that the terms of the agreement can not be discussed. Then it is the responsibility of the employer to ask you if you are subject to any previous agreements. And if they don't ask you, you can't be held liable for not telling them because your previous agreement prevents you from offering that information to them.