Freeglut 3, fgStructure.CurrentWindow is NULL

Tried to investigate the issue, why yade is crushing with the freeglut3. Looks like the crash is happening here:

GLint attribute_v_coord = fgStructure.CurrentWindow->Window.attribute_v_coord;

fgStructure.CurrentWindow is NULL, thus crash is happening.

In Yade crash happens in Gl1_Sphere::initGlutGlList() -> glutSolidSphere

Issue reported in the Freeglut tracker

https://sourceforge.net/p/freeglut/bugs/255/