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

WebCore/platform/graphics/skia/PlatformContextSkia.cpp

Index: WebCore/platform/graphics/skia/PlatformContextSkia.cpp
===================================================================
--- WebCore/platform/graphics/skia/PlatformContextSkia.cpp	(revision 33098)
+++ WebCore/platform/graphics/skia/PlatformContextSkia.cpp	(working copy)
@@ -343,6 +343,15 @@
     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);
@@ -351,10 +360,13 @@
     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);