Bug 934156 - Make the SVG elements' BuildPath methods return nullptr when the element is disabled. r=dholbert

content/svg/content/src/SVGCircleElement.cpp

@@ -96,15 +96,17 @@ SVGCircleElement::ConstructPath(gfxContext *aCtx)
 TemporaryRef<Path>
 SVGCircleElement::BuildPath()
 {
-  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
-
   float x, y, r;
   GetAnimatedLengthValues(&x, &y, &r, nullptr);
 
-  if (r > 0.0f) {
-    pathBuilder->Arc(Point(x, y), r, 0, Float(2*M_PI));
+  if (r <= 0.0f) {
+    return nullptr;
   }
 
+  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
+
+  pathBuilder->Arc(Point(x, y), r, 0, Float(2*M_PI));
+
   return pathBuilder->Finish();
 }
 

content/svg/content/src/SVGEllipseElement.cpp

@@ -107,15 +107,17 @@ SVGEllipseElement::ConstructPath(gfxContext *aCtx)
 TemporaryRef<Path>
 SVGEllipseElement::BuildPath()
 {
-  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
-
   float x, y, rx, ry;
   GetAnimatedLengthValues(&x, &y, &rx, &ry, nullptr);
 
-  if (rx > 0.0f && ry > 0.0f) {
-    AppendEllipseToPath(pathBuilder, Point(x, y), Size(2.0*rx, 2.0*ry));
+  if (rx <= 0.0f || ry <= 0.0f) {
+    return nullptr;
   }
 
+  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
+
+  AppendEllipseToPath(pathBuilder, Point(x, y), Size(2.0*rx, 2.0*ry));
+
   return pathBuilder->Finish();
 }
 

content/svg/content/src/SVGImageElement.cpp

@@ -245,20 +245,22 @@ SVGImageElement::BuildPath()
   // We get called in order to get bounds for this element, and for
   // hit-testing against it. For that we just pretend to be a rectangle.
 
-  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
-
   float x, y, width, height;
   GetAnimatedLengthValues(&x, &y, &width, &height, nullptr);
 
   if (width <= 0 || height <= 0) {
-    Rect r(x, y, width, height);
-    pathBuilder->MoveTo(r.TopLeft());
-    pathBuilder->LineTo(r.TopRight());
-    pathBuilder->LineTo(r.BottomRight());
-    pathBuilder->LineTo(r.BottomLeft());
-    pathBuilder->Close();
+    return nullptr;
   }
 
+  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
+
+  Rect r(x, y, width, height);
+  pathBuilder->MoveTo(r.TopLeft());
+  pathBuilder->LineTo(r.TopRight());
+  pathBuilder->LineTo(r.BottomRight());
+  pathBuilder->LineTo(r.BottomLeft());
+  pathBuilder->Close();
+
   return pathBuilder->Finish();
 }
 

content/svg/content/src/SVGRectElement.cpp

@@ -155,44 +155,46 @@ SVGRectElement::ConstructPath(gfxContext *aCtx)
 TemporaryRef<Path>
 SVGRectElement::BuildPath()
 {
-  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
-
   float x, y, width, height, rx, ry;
   GetAnimatedLengthValues(&x, &y, &width, &height, &rx, &ry, nullptr);
 
-  if (width > 0 && height > 0) {
-    rx = std::max(rx, 0.0f);
-    ry = std::max(ry, 0.0f);
+  if (width <= 0 || height <= 0) {
+    return nullptr;
+  }
 
-    if (rx == 0 && ry == 0) {
-      // Optimization for the no rounded corners case.
-      Rect r(x, y, width, height);
-      pathBuilder->MoveTo(r.TopLeft());
-      pathBuilder->LineTo(r.TopRight());
-      pathBuilder->LineTo(r.BottomRight());
-      pathBuilder->LineTo(r.BottomLeft());
-      pathBuilder->Close();
-    } else {
-      // If either the 'rx' or the 'ry' attribute isn't set, then we have to
-      // set it to the value of the other:
-      bool hasRx = mLengthAttributes[ATTR_RX].IsExplicitlySet();
-      bool hasRy = mLengthAttributes[ATTR_RY].IsExplicitlySet();
-      MOZ_ASSERT(hasRx || hasRy);
+  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
 
-      if (hasRx && !hasRy) {
-        ry = rx;
-      } else if (hasRy && !hasRx) {
-        rx = ry;
-      }
+  rx = std::max(rx, 0.0f);
+  ry = std::max(ry, 0.0f);
 
-      // Clamp rx and ry to half the rect's width and height respectively:
-      rx = std::min(rx, width / 2);
-      ry = std::min(ry, height / 2);
+  if (rx == 0 && ry == 0) {
+    // Optimization for the no rounded corners case.
+    Rect r(x, y, width, height);
+    pathBuilder->MoveTo(r.TopLeft());
+    pathBuilder->LineTo(r.TopRight());
+    pathBuilder->LineTo(r.BottomRight());
+    pathBuilder->LineTo(r.BottomLeft());
+    pathBuilder->Close();
+  } else {
+    // If either the 'rx' or the 'ry' attribute isn't set, then we have to
+    // set it to the value of the other:
+    bool hasRx = mLengthAttributes[ATTR_RX].IsExplicitlySet();
+    bool hasRy = mLengthAttributes[ATTR_RY].IsExplicitlySet();
+    MOZ_ASSERT(hasRx || hasRy);
 
-      Size cornerRadii(rx, ry);
-      Size radii[] = { cornerRadii, cornerRadii, cornerRadii, cornerRadii };
-      AppendRoundedRectToPath(pathBuilder, Rect(x, y, width, height), radii);
+    if (hasRx && !hasRy) {
+      ry = rx;
+    } else if (hasRy && !hasRx) {
+      rx = ry;
     }
+
+    // Clamp rx and ry to half the rect's width and height respectively:
+    rx = std::min(rx, width / 2);
+    ry = std::min(ry, height / 2);
+
+    Size cornerRadii(rx, ry);
+    Size radii[] = { cornerRadii, cornerRadii, cornerRadii, cornerRadii };
+    AppendRoundedRectToPath(pathBuilder, Rect(x, y, width, height), radii);
   }
 
   return pathBuilder->Finish();

content/svg/content/src/nsSVGPathGeometryElement.h

@@ -62,7 +62,7 @@ public:
 
   /**
    * Returns a Path that can be used to paint, hit-test or calculate bounds for
-   * this element.
+   * this element. May return nullptr if there is no [valid] path.
    */
   virtual mozilla::TemporaryRef<Path> BuildPath() = 0;
 

content/svg/content/src/nsSVGPolyElement.cpp

@@ -125,15 +125,17 @@ nsSVGPolyElement::ConstructPath(gfxContext *aCtx)
 TemporaryRef<Path>
 nsSVGPolyElement::BuildPath()
 {
-  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
-
   const SVGPointList &points = mPoints.GetAnimValue();
 
-  if (!points.IsEmpty()) {
-    pathBuilder->MoveTo(points[0]);
-    for (uint32_t i = 1; i < points.Length(); ++i) {
-      pathBuilder->LineTo(points[i]);
-    }
+  if (points.IsEmpty()) {
+    return nullptr;
+  }
+
+  RefPtr<PathBuilder> pathBuilder = CreatePathBuilder();
+
+  pathBuilder->MoveTo(points[0]);
+  for (uint32_t i = 1; i < points.Length(); ++i) {
+    pathBuilder->LineTo(points[i]);
   }
 
   return pathBuilder->Finish();