diff --git a/agg/include/agg_scanline_boolean_algebra.h b/agg/include/agg_scanline_boolean_algebra.h
index ad359e61b..bc2e9c9d5 100644
--- a/agg/include/agg_scanline_boolean_algebra.h
+++ b/agg/include/agg_scanline_boolean_algebra.h
@@ -850,8 +850,8 @@ namespace agg
         unsigned num1 = sl1.num_spans();
         unsigned num2 = sl2.num_spans();
 
-        typename Scanline1::const_iterator span1;
-        typename Scanline2::const_iterator span2;
+        typename Scanline1::const_iterator span1;// = sl1.begin();
+        typename Scanline2::const_iterator span2;// = sl2.begin();
 
         enum invalidation_e 
         { 
@@ -1046,7 +1046,11 @@ namespace agg
 
         // Calculate the union of the bounding boxes
         //-----------------
-        rect_i ur = unite_rectangles(r1, r2);
+        rect_i ur(1,1,0,0);
+             if(flag1 && flag2) ur = unite_rectangles(r1, r2);
+        else if(flag1)          ur = r1;
+        else if(flag2)          ur = r2;
+
         if(!ur.is_valid()) return;
 
         ren.prepare();
@@ -1176,7 +1180,7 @@ namespace agg
         ren.prepare();
 
         // A fake span2 processor
-        sbool_add_span_empty<Scanline1, Scanline> add_span2;
+        sbool_add_span_empty<Scanline2, Scanline> add_span2;
 
         // The main loop
         // Here we synchronize the scanlines with 
diff --git a/agg/include/agg_scanline_storage_aa.h b/agg/include/agg_scanline_storage_aa.h
index 4ea187e35..033e3291e 100644
--- a/agg/include/agg_scanline_storage_aa.h
+++ b/agg/include/agg_scanline_storage_aa.h
@@ -196,6 +196,7 @@ namespace agg
                     const T* covers;
                 };
 
+                const_iterator() : m_storage(0) {}
                 const_iterator(const embedded_scanline& sl) :
                     m_storage(sl.m_storage),
                     m_span_idx(sl.m_scanline.start_span)
@@ -554,6 +555,7 @@ namespace agg
                     const T* covers; 
                 };
 
+                const_iterator() : m_ptr(0) {}
                 const_iterator(const embedded_scanline& sl) :
                     m_ptr(sl.m_ptr),
                     m_dx(sl.m_dx)
@@ -721,9 +723,8 @@ namespace agg
                 m_min_y = read_int32() + m_dy;
                 m_max_x = read_int32() + m_dx;
                 m_max_y = read_int32() + m_dy;
-                return true;
             }
-            return false;
+            return m_ptr < m_end;
         }
 
         //--------------------------------------------------------------------
diff --git a/agg/include/agg_scanline_storage_bin.h b/agg/include/agg_scanline_storage_bin.h
index 07ea2ee36..d76001697 100644
--- a/agg/include/agg_scanline_storage_bin.h
+++ b/agg/include/agg_scanline_storage_bin.h
@@ -63,6 +63,7 @@ namespace agg
             class const_iterator
             {
             public:
+                const_iterator() : m_storage(0) {}
                 const_iterator(const embedded_scanline& sl) :
                     m_storage(sl.m_storage),
                     m_span_idx(sl.m_scanline.start_span)
@@ -360,6 +361,7 @@ namespace agg
                     int32 len;
                 };
 
+                const_iterator() : m_ptr(0) {}
                 const_iterator(const embedded_scanline& sl) :
                     m_ptr(sl.m_ptr),
                     m_dx(sl.m_dx)
@@ -503,9 +505,8 @@ namespace agg
                 m_min_y = read_int32() + m_dy;
                 m_max_x = read_int32() + m_dx;
                 m_max_y = read_int32() + m_dy;
-                return true;
             }
-            return false;
+            return m_ptr < m_end;
         }
 
         //--------------------------------------------------------------------
diff --git a/agg/include/agg_span_image_filter_gray.h b/agg/include/agg_span_image_filter_gray.h
index bdc30e342..002234498 100644
--- a/agg/include/agg_span_image_filter_gray.h
+++ b/agg/include/agg_span_image_filter_gray.h
@@ -123,7 +123,6 @@ namespace agg
                 int x_lr = x_hr >> image_subpixel_shift;
                 int y_lr = y_hr >> image_subpixel_shift;
 
-                unsigned weight;
                 fg = image_subpixel_scale * image_subpixel_scale / 2;
 
                 x_hr &= image_subpixel_mask;
@@ -139,7 +138,7 @@ namespace agg
                 fg    += *fg_ptr * (image_subpixel_scale - x_hr) * y_hr;
 
                 fg_ptr = (const value_type*)base_type::source().next_x();
-                fg    += fg_ptr * x_hr * y_hr;
+                fg    += *fg_ptr * x_hr * y_hr;
 
                 span->v = value_type(fg >> (image_subpixel_shift * 2));
                 span->a = base_mask;
diff --git a/agg/src/agg_curves.cpp b/agg/src/agg_curves.cpp
index 5cdf65eff..ae8cb5b9e 100644
--- a/agg/src/agg_curves.cpp
+++ b/agg/src/agg_curves.cpp
@@ -262,9 +262,9 @@ namespace agg
         double dx3 = x4 - x3;
         double dy3 = y4 - y3;
 
-        double len = sqrt(dx1 * dx1 + dy1 * dy1) + 
-                     sqrt(dx2 * dx2 + dy2 * dy2) + 
-                     sqrt(dx3 * dx3 + dy3 * dy3) * 0.25 * m_scale;
+        double len = (sqrt(dx1 * dx1 + dy1 * dy1) + 
+                      sqrt(dx2 * dx2 + dy2 * dy2) + 
+                      sqrt(dx3 * dx3 + dy3 * dy3)) * 0.25 * m_scale;
 
 #if defined(_MSC_VER) && _MSC_VER <= 1200
         m_num_steps = uround(MSC60_fix_ICE(len));