Prototype function gives error if it returns not void

[Neill3d]

For example, this code returns error

GLSLShader
{

//
// Prototypes
//
vec3 Blend(in vec3 base, in vec3 blend);

}

GLSLShader global BlendNormal
{
vec3 Blend(in vec3 base, in vec3 blend) {
return blend;
}
}

This is one code works

GLSLShader
{

//
// Prototypes
//
void something();  // !! needs this function to make it work
vec3 Blend(in vec3 base, in vec3 blend);

}

GLSLShader global BlendNormal
{
vec3 Blend(in vec3 base, in vec3 blend) {
return blend;
}
}