Fix 2 minor warning compil (unused variables)

include/boost/polygon/detail/minkowski.hpp

@@ -24,13 +24,13 @@ struct minkowski_offset {
   static void convolve_two_point_sequences(polygon_set& result, itrT1 ab, itrT1 ae, itrT2 bb, itrT2 be) {
     if(ab == ae || bb == be)
       return;
-    point first_a = *ab;
+//    point first_a = *ab;      // seems unused
     point prev_a = *ab;
     std::vector<point> vec;
     polygon poly;
     ++ab;
     for( ; ab != ae; ++ab) {
-      point first_b = *bb;
+//      point first_b = *bb;      // seems unused
       point prev_b = *bb;
       itrT2 tmpb = bb;
       ++tmpb;
@@ -62,11 +62,11 @@ struct minkowski_offset {
     a.get(a_polygons);
     b.get(b_polygons);
     for(std::size_t ai = 0; ai < a_polygons.size(); ++ai) {
-      convolve_point_sequence_with_polygons(result, begin_points(a_polygons[ai]), 
+      convolve_point_sequence_with_polygons(result, begin_points(a_polygons[ai]),
                                             end_points(a_polygons[ai]), b_polygons);
       for(typename polygon_with_holes_traits<polygon>::iterator_holes_type itrh = begin_holes(a_polygons[ai]);
           itrh != end_holes(a_polygons[ai]); ++itrh) {
-        convolve_point_sequence_with_polygons(result, begin_points(*itrh), 
+        convolve_point_sequence_with_polygons(result, begin_points(*itrh),
                                               end_points(*itrh), b_polygons);
       }
       for(std::size_t bi = 0; bi < b_polygons.size(); ++bi) {
@@ -100,9 +100,9 @@ struct minkowski_offset {
       ::boost::polygon::bloat(rect, 10);
       (*this) = rect - (*this); //invert
     }
-    //make_arc(std::vector<point_data< T> >& return_points,  
+    //make_arc(std::vector<point_data< T> >& return_points,
     //point_data< double> start, point_data< double>  end,
-    //point_data< double> center,  double r, unsigned int num_circle_segments)      
+    //point_data< double> center,  double r, unsigned int num_circle_segments)
     std::vector<point_data<coordinate_type> > circle;
     point_data<double> center(0.0, 0.0), start(0.0, (double)resizing);
     make_arc(circle, start, start, center, std::abs((double)resizing),

polygon/PolyLine.cpp

@@ -339,17 +339,6 @@ int CPolyLine::MakeKboolPoly( int aStart_contour, int aEnd_contour, std::vector<
         for( int ic = ic_st; ic<=ic_end; ic++ )
         {
             int style = side_style[ic];
-            int x2, y2;
-            if( ic < ic_end )
-            {
-                x2 = corner[ic + 1].x;
-                y2 = corner[ic + 1].y;
-            }
-            else
-            {
-                x2 = corner[ic_st].x;
-                y2 = corner[ic_st].y;
-            }
             if( style == STRAIGHT )
                 n_vertices++;
             else