Problem with Nvidia drivers for openGL

[Michael D Godfrey]

As you likely know,  Nvidia keeps the specs for their video
cards proprietary.  But, they allow distribution of their drivers
for Linux distributions.  The way that Fedora has made this
more convenient is to "recognize" a repository for "non-free"
software (i.e. software for which source is not available).  So,
many people whose machines have Nvidia cards use this
mechanism to get the "accelerated" drivers.  These include
Nvidia coded openGL libraries.

After this introduction, I have found that the fltk backend works
with the Nvidia openGL libraries except in one case: the use
of NX such that the NX server is running on a system with the
Nvidia openGL libraries installed. Plotting in an NX window
running on a client connected the an NX server on a Nvidia
machine with fltk works fine until you quit Octave.  Then you get
(if running Octave under gdb):

octave:1> plot([1:200])
octave:2> quit


Program received signal SIGSEGV, Segmentation fault.
0x0000003be7497210 in ?? () from /usr/lib64/nvidia/libGL.so.1

This can reasonably be classified as an NX problem.  Running
directly at the console on the machine works OK.  NX server is
supposed to give you a virtual console.  So, something that they
do causes the Nvidia library libGL.so.1 to seg fault.

I can try sending this in to the NX folks (I do have a paid for
server license), but I doubt if they will consider this to be very
high priority.  I will have to send them a copy of the current
development  Octave (or explain how to download it using hg).

Anyhow, the purpose of this email is to document the correct
facts about the seg fault problem that I have reported previously.

All other connection paths between Nvidia machines running Fedora
11 now work without problems (since I figured out the "leftover"
libraries problem, which was also causing seg faults).  And, by the
way, builds of the current development system work without problems
of FC11 x86_64 machines.

Michael