setDesiredOrientation method not working in C++

[mjoshi07]

if only setDesiredOrientation() method is called, then the current pose (turtlesim_pose.theta) does not update its value and is always 0. Therefore if I repeatedly run, let's say setDesiredOrientation(degrees2radians(90)) the turtle rotates by 90 degrees counter-clockwise every time I run it, instead of rotating only once.