NVIDIA GPL violation

[Ryan S. Dancey]

Reading /. today about NVIDIA using some GPL'd code in their XFree86 driver
raised some questions for me.

>From the description given, it seems that NVIDIA used at most a handful of
lines of code from the middle of someone else's program; that program being
covered by the GPL.  The author of that code contacted the company and
informed them that they were violating the GPL and that they needed to
remedy their breach of contract.

I'm assuming that it is the stance of the community that the use of >any<
GPL'd code is sufficient to create a "derivative work" and thus trigger the
terms of the license itself.

I'm wondering if that is in fact an accurate interpretation of how a court
might rule on the matter.  Since the GPL is a copyright license, and
copyright covers the expression of ideas, not the ideas itself, the small
part of GPL'd code used by NVIDIA might not cross that line from
"expression" from "idea".

Is there any standard test the courts have used to determine when a software
program is derivative of another?  Is the test "any code re-use at all" or
is there some test of the ratio of new to recycled code?

Ryan