driver: trajectories where len(pos) != len(vel) != len(acc) lead to strange motions

[gavanderhoorn]

Observed this on our SIA20F+rail: if a JointTrajectory contains JointTrajectoryPoints with inconsistent position, velocity or acceleration lists (compared to the names field), the driver will accept the trajectory and send 'strange' values for the missing elements.

'strange' typically means: non-zero, which can lead to trajectories with non-zero start and end velocities and accelerations, which result in either wrong or 'alternative' motion for joints that are assigned those values.

[gavanderhoorn]

I've not investigated this further, but I guess there is some unitialised memory being used to set or copy values for the missing elements of the arrays.