> On Nov 5, 2024, at 18:58, Warner Losh <imp@bsdimp.com> wrote:
…
> These days, most open source authors would
> replace the copyright statement with their own for such an extensive rewrite
> since the diff was over 2x the size of the original file (another very imperfect
> measure). Though the comments remaining identical is troublesome because
> they are the parts of the code that are the most creative and subject to the
> most freedom while the for loops and such are largely dictated by the problem
> or C language and customary style.
This was interesting to me. I’ve been writing various open source for 20+ years and I think maybe I was given a much stricter rule to follow when I started out and which I’ve followed since — it may very well be wrong but it’s what I’ve followed.
If I started with some code with a copyright at the top, and I rewrote every line I would not replace the copyright but add mine to the file. I was told this was the correct action b/c you aren’t allowed to use the previous code as an aide to writing your new code and consider it only your own, it’s derivative in that case.
If you rewrote everything, that's an original work. There's nothing in copyright law that talks about process only the end result. While it is nice to leave yhe original copyright, it's not necessary when there's no original material left. And there is some incentive to remove it because you don't want to incorrectly represent who has IP in the file.
Maybe this is just overly careful, but it’s what I’ve done in all my projects (starting back in the 90s with NetBSD and on to contributing to many other open source projects over time).
Yea. While many would replace the copyright for the scenario I described, many would add their copyright. It's a judgment call: are the changes transformative to the work or not? There are several creators that take old Disney film footage and legally remox it into something new. The original is clearly there, but changed enough to be outside copyright protection. Sadly, there are no simple, universal rules that let you do this analysis completely mechanically.
Warner