Still not a copyright infringement [LWN.net]

Still not a copyright infringement

Posted Sep 17, 2003 1:10 UTC (Wed) by Zakaelri (guest, #15087)
In reply to: Still not a copyright infringement by rjamestaylor
Parent article: Maybe SCO had a point

I would think this is (approximately) how the whole process wouold be
done:

1) Do a unified diff on Linux vs System V
2) Do a unified diff on Linux vs System 32
3) Compare the Diffs, remove any Duplicate lines (this would extract the
things that are identical between System V, System 32, and Linux...
leaving only the chnages.)
4) Inspect the remaining lines in the System V diff, then figure out where
they came from in the linux codebase (line numbers for each file).
5) Send the resultant line numbers/files/etc to the kernel list, so they
can investigate where they all came from, and change anything that should
be changed.

The only problem with this technique is that the files would have to have
the same names/etc for it to work... and in some of the cases (such as the
SGI code case, already dissected by Bruce Perens and (by this point)
probably numerous others, if I recall correctly) this is not the case.

If there are files that are renamed, or code that is copyrighted but used
elsewhere in the same code, then the algorithim will probably escalate
pretty quickly to be NP-complete.

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Still not a copyright infringement

Posted Sep 17, 2003 1:20 UTC (Wed) by Zakaelri (guest, #15087) [Link]

I am very sorry for the unreadability of the third and last paragraph in
the above post... Let's see if I can make sense of them:

The only problem with this technique is that the files would have to have
the same names/etc for it to work... If memory serves, there were some
cases (such as the SGI driver code, previously dissected and discussed by
Bruce Perens) where the copied code was actually in a different file than
it's System V equivalent. This makes the problem of finding copyright
infringement in the current codebase become unmanagable... the complexity
of the algorithim necessary to complete such a task might as well be
NP-complete.