[ODE] stack pointers

[Russ Smith]

Shaul Kedem wrote:
> Reproducing the bug on my machine is very easy: simply
> compile with NUM 100 and press 'B' key without
> stopping, sooner or later the whole thing crash.

if you create boxes too quickly in the demo (pressing B too fast)
then some boxes are created inside other boxes - the collision
reaction can cause these boxes to pick up high velocity and
destabilize the sim. so a better test is to wait until the existing
boxes have settled down before adding a new box (or add something that
creates a new box every N steps).

are you running on a platform where numeric exceptions cause fatal
errors? on my platform (linux) you can have some body-joint islands
"crash" (i.e. the number go infinite) while the rest of the sim is 
fine. it's possible that numeric exceptions are causing your crash.

if there is an ODE problem, we'll have to capture the exact sim state
that causes the problem - i.e. things need to be reproducable before
they can be debugged. this has been an issue several times before.

russ.

--
Russell Smith
http://www.q12.org