On Mon, Nov 4, 2024 at 6:32 PM ron minnich <rminnich@gmail.com> wrote:

I had people relate to me, at least once, cases of utterly independent implementations of a function that were byte for byte the same, as found in one court case a friend of mine (now deceased) got pulled into. He had to prove he'd written his code from scratch. But these were pretty simple functions. I don't know if bmap qualifies ...

How could this happen? I don't know, but the court case that long predated SCO. The only conclusion I can reach
is that when enough techniques, ideas, mailling lists, discussions, and documents become part of a shared culture, the code which people create might be the same. A weird parallel evolution of code.

This is the legal principle of sene. a faire: some things are just endemic to the genre that they have no copyright protection. If there's no other way (or other sane way) to implement something, then two people can (and do) reimplement it w/o there being any copyright infringement. There's a complicated way to break down code into its parts, and see what was copied vs what's necessary to implement an algorithm (which has no copyright protection, and no patent protection in the era we're talking about).

It's what keeps the lawyers employed.

Warner

On Mon, Nov 4, 2024 at 5:09 PM Larry McVoy <lm@mcvoy.com> wrote:
The thing I never got a reasonable answer to was I found code in BSD that
was identical to code going back to at least V7. Find bmap() in the UFS
code and then find the same in V7. I might be wrong about V7, might be
32V, might be V6. I don't think it matters, it's the same in all of them.

bmap() is the code that maps a logical block to a phsyical block,
I'm quite familiar with it because I rewrote it to bmap_write() and
bmap_read() as part of making UFS do extents:

http://mcvoy.com/lm/papers/SunOS.ufs_clustering.pdf

When all the lawsuits were going on, since I knew that code really well,
I went off and looked and the BSD code at that time had bit for bit
identical bmap() implementations.

I never understood why BSD could claim they rewrote everything when they
clearly had not rewritten that.

I've raised this question before and I just went and looked, bmap() has
changed. I'm pretty sure I have Kirk's BSD source releases, if I do,
I'm 100% sure I can back up what I'm saying. Not sure I care enough to
do so, it's all water under the bridge at this point.
--
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Larry McVoy Retired to fishing http://www.mcvoy.com/lm/boat