As far as I was told, this is not enough, you have to add extra legal care, even more if you are on an 'executive' type job contract, and you have to double that if there is "too much" connection/"look-a-like", between the software at work and the open source software you contribute to "at home".

On an french executive like contract, the boundary between "at home" and "at work" is very, very blurry.