We are using some of my pre-existing, personally copyrighted open source software libraries at my employer. Recently they have asked me to "fix" the copyright so that it is theirs.
I have no objection to them owning a version of the code, i.e. that they own the copyright to, however I want to retain the ownership and copyright of the original code as it existed before I came here.
Is there a reasonably painless way to achieve this?
Cross-posted from Open Source, per a commenter's suggestion. https://opensource.stackexchange.com/questions/6230/can-i-assign-a-2nd-copyright-to-my-employer