From Olivier: - Protection added in TPad::x3d in case there is no TView defined in the   current TPad. Trying to visualize a such TPad with a 3D viewer (ogl or   x3d) produced a segmentation fault.
From Olivier:
- Protection added in TPad::x3d in case there is no TView defined in the
  current TPad. Trying to visualize a such TPad with a 3D viewer (ogl or
  x3d) produced a segmentation fault.


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@10697 27541ba8-7e3a-0410-8455-c3a389f83636

bbannier/ROOT,dawehner/root,bbannier/ROOT,dawehner/root,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,bbannier/ROOT