change SkPoint::setLength to set itself to (0,0) if it starting length is degenerate

src/core/SkPath.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkBuffer.h"
@@ skipping 1269 matching lines @@
     DIRTY_AFTER_EDIT;
     SkDEBUGCODE(this->validate();)
 }
 
 /*
     Need to handle the case when the angle is sharp, and our computed end-points
     for the arc go behind pt1 and/or p2...
 */
 void SkPath::arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
                    SkScalar radius) {
-    SkVector    before, after;
+    if (radius == 0) {
+        this->lineTo(x1, y1);
+        return;
+    }
+
+    SkVector before, after;
 
     // need to know our prev pt so we can construct tangent vectors
     {
         SkPoint start;
         this->getLastPt(&start);
         // Handle degenerate cases by adding a line to the first point and
         // bailing out.
-        if ((x1 == start.fX && y1 == start.fY) ||
-            (x1 == x2 && y1 == y2) ||
-            radius == 0) {
-            this->lineTo(x1, y1);
-            return;
-        }
         before.setNormalize(x1 - start.fX, y1 - start.fY);
         after.setNormalize(x2 - x1, y2 - y1);
     }
 
     SkScalar cosh = SkPoint::DotProduct(before, after);
     SkScalar sinh = SkPoint::CrossProduct(before, after);
 
     if (SkScalarNearlyZero(sinh)) {   // angle is too tight
         this->lineTo(x1, y1);
         return;
@@ skipping 1565 matching lines @@
     switch (this->getFillType()) {
         case SkPath::kEvenOdd_FillType:
         case SkPath::kInverseEvenOdd_FillType:
             w &= 1;
             break;
         default:
             break;
     }
     return SkToBool(w);
 }