From Bill Prendergast, "Found a typo in CameraRenderOrderSortOp in osg/GraphicsContext.cpp

(V2.6.0 and prior) as noted below:

struct CameraRenderOrderSortOp
{
   inline bool operator() (const Camera* lhs,const Camera* rhs) const
   {
       if (lhs->getRenderOrder()<rhs->getRenderOrder()) return true;
       if (rhs->getRenderOrder()<lhs->getRenderOrder()) return false;
--->    return lhs->getRenderOrderNum()<lhs->getRenderOrderNum();
              ^^^                      ^^^
   }
};

Corrected code attached."

src/osg/GraphicsContext.cpp

@@ -667,7 +667,7 @@ struct CameraRenderOrderSortOp
     {
         if (lhs->getRenderOrder()<rhs->getRenderOrder()) return true;
         if (rhs->getRenderOrder()<lhs->getRenderOrder()) return false;
-        return lhs->getRenderOrderNum()<lhs->getRenderOrderNum();
+        return lhs->getRenderOrderNum()<rhs->getRenderOrderNum();
     }
 };