diff --git a/ChangeLog b/ChangeLog
index 98bb7d24a5..fe2c9fa35a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-02-10  Sven Neumann  <sven@gimp.org>
+
+	* app/core/gimpcoords-interpolate.c
+	* app/core/gimpbrush-transform.c
+	* app/paint/gimppaintoptions.c
+	* app/display/gimpdisplayshell-coords.c: applied patch from Alexia
+	Death that fixes the direction of brush rotation (bug #520078).
+
 2009-02-10  Sven Neumann  <sven@gimp.org>
 
 	* app/display/gimpdisplayshell-coords.c
diff --git a/app/core/gimpbrush-transform.c b/app/core/gimpbrush-transform.c
index e25ff00ce4..56bbee85ee 100644
--- a/app/core/gimpbrush-transform.c
+++ b/app/core/gimpbrush-transform.c
@@ -205,7 +205,7 @@ gimp_brush_transform_matrix (GimpBrush   *brush,
 
   gimp_matrix3_identity (matrix);
   gimp_matrix3_translate (matrix, - center_x, - center_x);
-  gimp_matrix3_rotate (matrix, 2 * G_PI * angle);
+  gimp_matrix3_rotate (matrix, -2 * G_PI * angle);
   gimp_matrix3_translate (matrix, center_x, center_y);
   gimp_matrix3_scale (matrix, scale, scale);
 }
diff --git a/app/core/gimpcoords-interpolate.c b/app/core/gimpcoords-interpolate.c
index ae6062d8c3..657e38d3ec 100644
--- a/app/core/gimpcoords-interpolate.c
+++ b/app/core/gimpcoords-interpolate.c
@@ -40,11 +40,11 @@ static void     gimp_coords_interpolate_bezier_internal (const GimpCoords  bezie
                                                          GArray          **ret_coords,
                                                          GArray          **ret_params,
                                                          gint              depth);
-static gdouble  gimp_coords_get_catmull_spline_point    (gdouble           t,
-                                                         gdouble           p0,
-                                                         gdouble           p1,
-                                                         gdouble           p2,
-                                                         gdouble           p3);
+static gdouble  gimp_coords_get_catmull_spline_point    (const gdouble     t,
+                                                         const gdouble     p0,
+                                                         const gdouble     p1,
+                                                         const gdouble     p2,
+                                                         const gdouble     p3);
 
 /* Functions for bezier subdivision */
 
@@ -226,15 +226,15 @@ gimp_coords_interpolate_catmull (const GimpCoords   catmul_pt1,
                                  GArray           **ret_coords,
                                  GArray           **ret_params)
 {
-  gdouble        delta_x, delta_y;
-  gdouble        distance;
-  gint           num_points;
-  gint           n;
+  gdouble     delta_x, delta_y;
+  gdouble     distance;
+  gint        num_points;
+  gint        n;
 
-  GimpCoords     past_coords;
-  GimpCoords     start_coords;
-  GimpCoords     end_coords;
-  GimpCoords     future_coords;
+  GimpCoords  past_coords;
+  GimpCoords  start_coords;
+  GimpCoords  end_coords;
+  GimpCoords  future_coords;
 
   delta_x        = catmul_pt3.x - catmul_pt2.x;
   delta_y        = catmul_pt3.y - catmul_pt2.y;
@@ -323,7 +323,7 @@ gimp_coords_interpolate_catmull (const GimpCoords   catmul_pt1,
         }
       else
         {
-          res_coords.direction = atan (delta_y / delta_x) / (2 * G_PI);
+          res_coords.direction = atan ((- delta_y) / delta_x) / (2 * G_PI);
 
           if (delta_x > 0.0)
             res_coords.direction = res_coords.direction + 0.5;
@@ -337,11 +337,11 @@ gimp_coords_interpolate_catmull (const GimpCoords   catmul_pt1,
 }
 
 static gdouble
-gimp_coords_get_catmull_spline_point (gdouble  t,
-                                      gdouble  p0,
-                                      gdouble  p1,
-                                      gdouble  p2,
-                                      gdouble  p3)
+gimp_coords_get_catmull_spline_point (const gdouble  t,
+                                      const gdouble  p0,
+                                      const gdouble  p1,
+                                      const gdouble  p2,
+                                      const gdouble  p3)
 {
 
   return ((((-t + 2.0) * t - 1.0) * t / 2.0)        * p0 +
diff --git a/app/display/gimpdisplayshell-coords.c b/app/display/gimpdisplayshell-coords.c
index 8dece2373a..2d6f5621f8 100644
--- a/app/display/gimpdisplayshell-coords.c
+++ b/app/display/gimpdisplayshell-coords.c
@@ -298,12 +298,13 @@ gimp_display_shell_eval_event (GimpDisplayShell *shell,
         }
       else
         {
-          coords->direction = atan (delta_y / delta_x) / (2 * G_PI);
-          if (delta_x > 0.0)
+          coords->direction = atan ((- 1.0 * delta_y) / delta_x) / (2 * G_PI);
+          if (delta_x < 0.0)
             coords->direction = coords->direction + 0.5;
         }
 
        delta_dir = coords->direction - shell->last_coords.direction;
+
        if ((fabs (delta_dir) > 0.5) && (delta_dir < 0.0))
          coords->direction = 0.3 * coords->direction + 0.7 * (shell->last_coords.direction - 1.0);
        else if ((fabs (delta_dir) > 0.5) && (delta_dir > 0.0))
diff --git a/app/paint/gimppaintoptions.c b/app/paint/gimppaintoptions.c
index f45d5fd0e9..9c9b2e4e8b 100644
--- a/app/paint/gimppaintoptions.c
+++ b/app/paint/gimppaintoptions.c
@@ -503,7 +503,7 @@ gimp_paint_options_set_property (GObject      *object,
       break;
 
     case PROP_BRUSH_ANGLE:
-      options->brush_angle = g_value_get_double (value) / 360.0;
+      options->brush_angle = - 1.0 * g_value_get_double (value) / 360.0; /* let's make the angle mathematically correct */
       break;
 
     case PROP_APPLICATION_MODE:
@@ -742,7 +742,7 @@ gimp_paint_options_get_property (GObject    *object,
       break;
 
     case PROP_BRUSH_ANGLE:
-      g_value_set_double (value, options->brush_angle * 360.0);
+      g_value_set_double (value, - 1.0 * options->brush_angle * 360.0); /* mathematically correct -> intuitively correct */
       break;
 
     case PROP_APPLICATION_MODE: