It would depend on the local laws and the wording of the contract. It would be highly unusual for an employer to claim ownership over pre-existing IP (unless th

It would depend on the local laws and the wording of the contract. It would be highly unusual for an employer to claim ownership over pre-existing IP (unless that was the reason they were hiring you). Of course even if pre-existing IP is owned you don't want to be in a position where contributions to the same project after date of new employment are owned by the company, creating a divide in ownership.