Merge WebKit 51319: Chromium Linux: Limit the stroke width and mitre limit....

WebCore/platform/graphics/skia/PlatformContextSkia.cpp

 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
  * 
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  * 
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 325 matching lines @@
     paint->setLooper(m_state->m_looper);
 }
 
 void PlatformContextSkia::setupPaintForFilling(SkPaint* paint) const
 {
     setupPaintCommon(paint);
     paint->setColor(m_state->applyAlpha(m_state->m_fillColor));
     paint->setShader(m_state->m_fillShader);
 }
 
+static SkScalar scalarBound(SkScalar v, SkScalar min, SkScalar max)
+{
+    if (v < min)
+        return min;
+    if (v > max)
+        return max;
+    return v;
+}
+
 float PlatformContextSkia::setupPaintForStroking(SkPaint* paint, SkRect* rect, int length) const
 {
     setupPaintCommon(paint);
     float width = m_state->m_strokeThickness;
 
     paint->setColor(m_state->applyAlpha(m_state->m_strokeColor));
     paint->setShader(m_state->m_strokeShader);
     paint->setStyle(SkPaint::kStroke_Style);
-    paint->setStrokeWidth(SkFloatToScalar(width));
+    // The limits here (512 and 256) were made up but are hopefully large
+    // enough to be reasonable. They are, empirically, small enough not to
+    // cause overflows in Skia.
+    paint->setStrokeWidth(scalarBound(SkFloatToScalar(width), 0, 512));
     paint->setStrokeCap(m_state->m_lineCap);
     paint->setStrokeJoin(m_state->m_lineJoin);
-    paint->setStrokeMiter(SkFloatToScalar(m_state->m_miterLimit));
+    paint->setStrokeMiter(scalarBound(SkFloatToScalar(m_state->m_miterLimit), 0, 256));
 
     if (m_state->m_dash)
         paint->setPathEffect(m_state->m_dash);
     else {
         switch (m_state->m_strokeStyle) {
         case WebCore::NoStroke:
         case WebCore::SolidStroke:
             break;
         case WebCore::DashedStroke:
             width = m_state->m_dashRatio * width;
@@ skipping 234 matching lines @@
     paint.setAntiAlias(true);
     paint.setStyle(SkPaint::kFill_Style);
 
     for (size_t i = paths.size() - 1; i < paths.size(); --i) {
         paths[i].setFillType(SkPath::kInverseWinding_FillType);
         m_canvas->drawPath(paths[i], paint);
     }
 
     m_canvas->restore();
 }