gdiplus: Reuse point when calling GdipAddPathArc on open figure.

dlls/gdiplus/graphicspath.c

@@ -241,7 +241,9 @@ static GpStatus extend_current_figure(GpPath *path, GDIPCONST PointF *points, IN
 GpStatus WINGDIPAPI GdipAddPathArc(GpPath *path, REAL x1, REAL y1, REAL x2,
     REAL y2, REAL startAngle, REAL sweepAngle)
 {
-    INT count, old_count, i;
+    GpPointF *points;
+    GpStatus status;
+    INT count;
 
     TRACE("(%p, %.2f, %.2f, %.2f, %.2f, %.2f, %.2f)\n",
           path, x1, y1, x2, y2, startAngle, sweepAngle);
@@ -250,26 +252,19 @@ GpStatus WINGDIPAPI GdipAddPathArc(GpPath *path, REAL x1, REAL y1, REAL x2,
         return InvalidParameter;
 
     count = arc2polybezier(NULL, x1, y1, x2, y2, startAngle, sweepAngle);
-
     if(count == 0)
         return Ok;
-    if(!lengthen_path(path, count))
+
+    points = heap_alloc_zero(sizeof(GpPointF)*count);
+    if(!points)
         return OutOfMemory;
 
-    old_count = path->pathdata.Count;
-    arc2polybezier(&path->pathdata.Points[old_count], x1, y1, x2, y2,
-                   startAngle, sweepAngle);
+    arc2polybezier(points, x1, y1, x2, y2, startAngle, sweepAngle);
 
-    for(i = 0; i < count; i++){
-        path->pathdata.Types[old_count + i] = PathPointTypeBezier;
-    }
-
-    path->pathdata.Types[old_count] =
-        (path->newfigure ? PathPointTypeStart : PathPointTypeLine);
-    path->newfigure = FALSE;
-    path->pathdata.Count += count;
+    status = extend_current_figure(path, points, count, PathPointTypeBezier);
 
-    return Ok;
+    heap_free(points);
+    return status;
 }
 
 /*******************************************************************************

dlls/gdiplus/tests/graphicspath.c

@@ -435,6 +435,13 @@ static path_test_t arc_path[] = {
     {450.9, 824.1, PathPointTypeBezier, 0, 0}, /*36*/
     {540.4, 676.9, PathPointTypeBezier | PathPointTypeCloseSubpath, 0, 1} /*37*/
     };
+static path_test_t arc_path2[] = {
+    {1.0, 0.0, PathPointTypeStart, 0, 0}, /*0*/
+    {1.0, 0.5, PathPointTypeLine, 0, 0}, /*1*/
+    {1.0, 0.776142, PathPointTypeBezier, 0, 0}, /*2*/
+    {0.776142, 1.0, PathPointTypeBezier, 0, 0}, /*3*/
+    {0.5, 1.0, PathPointTypeBezier, 0, 0} /*4*/
+    };
 
 static void test_arc(void)
 {
@@ -463,6 +470,13 @@ static void test_arc(void)
 
     ok_path(path, arc_path, ARRAY_SIZE(arc_path), FALSE);
 
+    GdipResetPath(path);
+    GdipAddPathLine(path, 1.0, 0.0, 1.0, 0.5);
+    status = GdipAddPathArc(path, 0.0, 0.0, 1.0, 1.0, 0.0, 90.0);
+    expect(Ok, status);
+
+    ok_path_fudge(path, arc_path2, ARRAY_SIZE(arc_path2), FALSE, 0.000005);
+
     GdipDeletePath(path);
 }