limit the number of points in SkDashPathEffect::asPoints

tests/DashPathEffectTest.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 
 #include "SkDashPathEffect.h"
 #include "SkWriteBuffer.h"
 #include "SkStrokeRec.h"
+#include "SkCanvas.h"
+#include "SkSurface.h"
 
 // crbug.com/348821 was rooted in SkDashPathEffect refusing to flatten and unflatten itself when
 // the effect is nonsense.  Here we test that it fails when passed nonsense parameters.
 
 DEF_TEST(DashPathEffectTest_crbug_348821, r) {
     SkScalar intervals[] = { 1.76934361e+36f, 2.80259693e-45f };  // Values from bug.
     const int count = 2;
     SkScalar phase = SK_ScalarInfinity;  // Used to force a nonsense effect.
     sk_sp<SkPathEffect> dash(SkDashPathEffect::Make(intervals, count, phase));
 
@@ skipping 69 matching lines @@
     SkScalar intervals[2] = { 1, 1 };
     sk_sp<SkPathEffect> dash(SkDashPathEffect::Make(intervals, 2, 0));
 
     SkPaint paint;
     paint.setStyle(SkPaint::kStroke_Style);
     paint.setPathEffect(dash);
 
     SkPath fill;
     paint.getFillPath(path, &fill);
 }
+
+// Verify that long lines with many dashes don't cause overflows/OOMs.
+DEF_TEST(DashPathEffectTest_asPoints_limit, r) {
+    sk_sp<SkSurface> surface(SkSurface::MakeRaster(SkImageInfo::MakeN32Premul(256, 256)));
+    SkCanvas* canvas = surface->getCanvas();
+
+    SkPaint p;
+    p.setStyle(SkPaint::kStroke_Style);
+    // force the bounds to outset by a large amount
+    p.setStrokeWidth(5.0e10f);
+    const SkScalar intervals[] = { 1, 1 };
+    p.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
+    canvas->drawLine(1, 1, 1, 5.0e10f, p);
+}