Hello,
I noticed a number of log messages like the following on the boxes
I use:

  [ 8368.413929] winduprobot[8149]: segfault at c01465130 ip 000000000041136a sp 00007fffa56dbf08 error 4 in winduprobot[400000+9c000]

After finding out that winduprobot is a newly added hack shipped in
package xscreensaver-gl, I tried to reproduce the issue by simply
running it in a dedicated window:

  $ /usr/lib/xscreensaver/winduprobot
  Segmentation fault

After a while, the hack segfaulted, as I expected.

I am under the impression that the bug is easily reproducible.

Please investigate and fix the bug and/or forward my report upstream.

Thanks for your time!
Bye.

What is the resolution and colour depth you are using? Which graphics
card?

Can you please try to get more information, for example running:
gdb /usr/lib/xscreensaver/winduprobot
(gdb) run
(gdb) where

Regards,
Tormod

On Sat, 1 Nov 2014 11:47:56 +0100 Tormod Volden wrote:

[...]

You're welcome, thanks to you for your reply.

I am experiencing the bug on a number of different boxes, at different
resolutions (for instance: 1600x900).
Color depth is always 24 bit.
Graphics cards are different models, but all of them are Intel
integrated chips (for instance: Intel Corporation 82G965 Integrated
Graphics Controller).
Starting program: /usr/lib/xscreensaver/winduprobot
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x000000000041136a in ?? ()
(gdb) where
#0  0x000000000041136a in ?? ()
#1  0x000000000040adbd in ?? ()
#2  0x000000000040ce01 in ?? ()
#3  0x000000000040f049 in ?? ()
#4  0x0000000000404b50 in ?? ()
#5  0x00007ffff5081b45 in __libc_start_main ()
   from /lib/x86_64-linux-gnu/libc.so.6
#6  0x000000000040552a in ?? ()


I hope this helps in pinpointing the problem.
Thanks for your time!