glLightModel vs GL_VERTEX_PROGRAM_TWO_SIDE

OpenGL OpenGL: Advanced Coding
1

Should the function:
glEnable(GL_VERTEX_PROGRAM_TWO_SIDE)
do something in a program that don’t use any shader ?

If YES, why ? And what do we do with
glLightModel(GL_LIGHT_MODEL_TWO_SIDE,1) ?

If NO, is this an nVIDIA driver bug ? See my example program here

2

I don’t know what happens when you have glEnable(GL_VERTEX_PROGRAM_TWO_SIDE) and not using a vertex shader.

With glLightModel(GL_LIGHT_MODEL_TWO_SIDE,1) , sounds like both tris should be white. Try using glMaterial instead of color tracking.