[osg-users] PolygonMode::FRONT / BACK causes Warning

[Ariasgore]

Hello,

I am testing some Code and trying to look at some Wireframe Models, I use 
the following line of code, first using FRONT_AND_BACK PolygonMode

osg::PolygonMode * pm = new 
osg::PolygonMode(osg::PolygonMode::FRONT_AND_BACK, osg::PolygonMode::LINE);

That works, both sides are rendered as wireframe, but then I tried to use 
FRONT or BACK only with

osg::PolygonMode * pm = new osg::PolygonMode(osg::PolygonMode::FRONT, 
osg::PolygonMode::LINE);
osg::PolygonMode * pm = new osg::PolygonMode(osg::PolygonMode::BACK, 
osg::PolygonMode::LINE);
These are the valid modes I found in the documentation and they work, I see 
either only Front as Wireframe or the Back.

But my console window is flooded with following warning:
"Warning: detected OpenGL error  'invalid enumerant' after 
RenderBin::draw(,)"

Where is the problem here?

Greets