Use the appropriate color based on visitedness for the color or fallback color parts of 'fill' and 'stroke'. (Bug 147777) r=jwatt

layout/style/nsStyleContext.cpp

@@ -730,13 +730,20 @@ nsStyleContext::GetVisitedDependentColor(nsCSSProperty aProperty)
 
   colors[1] = ExtractColor(aProperty, visitedStyle);
 
+  return nsStyleContext::CombineVisitedColors(colors,
+                                              this->RelevantLinkVisited());
+}
+
+/* static */ nscolor
+nsStyleContext::CombineVisitedColors(nscolor *aColors, PRBool aLinkIsVisited)
+{
   // NOTE: We want this code to have as little timing dependence as
   // possible on whether this->RelevantLinkVisited() is true.
   const ColorIndexSet &set =
-    gVisitedIndices[this->RelevantLinkVisited() ? 1 : 0];
+    gVisitedIndices[aLinkIsVisited ? 1 : 0];
 
-  nscolor colorColor = colors[set.colorIndex];
+  nscolor colorColor = aColors[set.colorIndex];
-  nscolor alphaColor = colors[set.alphaIndex];
+  nscolor alphaColor = aColors[set.alphaIndex];
   return NS_RGBA(NS_GET_R(colorColor), NS_GET_G(colorColor),
                  NS_GET_B(colorColor), NS_GET_A(alphaColor));
 }

layout/style/nsStyleContext.h

@@ -261,6 +261,16 @@ public:
    */
   NS_HIDDEN_(nscolor) GetVisitedDependentColor(nsCSSProperty aProperty);
 
+  /**
+   * aColors should be a two element array of nscolor in which the first
+   * color is the unvisited color and the second is the visited color.
+   *
+   * Combine the R, G, and B components of whichever of aColors should
+   * be used based on aLinkIsVisited with the A component of aColors[0].
+   */
+  static nscolor CombineVisitedColors(nscolor *aColors,
+                                      PRBool aLinkIsVisited);
+
 #ifdef DEBUG
   NS_HIDDEN_(void) List(FILE* out, PRInt32 aIndent);
 #endif

layout/svg/base/src/nsSVGGeometryFrame.cpp

@@ -191,6 +191,37 @@ SetupCairoColor(gfxContext *aContext, nscolor aRGB, float aOpacity)
                              NS_GET_A(aRGB)/255.0 * aOpacity));
 }
 
+static void
+SetupFallbackOrPaintColor(gfxContext *aContext, nsStyleContext *aStyleContext,
+                          nsStyleSVGPaint nsStyleSVG::*aFillOrStroke,
+                          float aOpacity)
+{
+  const nsStyleSVGPaint &paint = aStyleContext->GetStyleSVG()->*aFillOrStroke;
+  nsStyleContext *styleIfVisited = aStyleContext->GetStyleIfVisited();
+  PRBool isServer = paint.mType == eStyleSVGPaintType_Server;
+  nscolor color = isServer ? paint.mFallbackColor : paint.mPaint.mColor;
+  if (styleIfVisited) {
+    const nsStyleSVGPaint &paintIfVisited =
+      styleIfVisited->GetStyleSVG()->*aFillOrStroke;
+    // To prevent Web content from detecting if a user has visited a URL
+    // (via URL loading triggered by paint servers or performance
+    // differences between paint servers or between a paint server and a
+    // color), we do not allow whether links are visited to change which
+    // paint server is used or switch between paint servers and simple
+    // colors.  A :visited style may only override a simple color with
+    // another simple color.
+    if (paintIfVisited.mType == eStyleSVGPaintType_Color &&
+        paint.mType == eStyleSVGPaintType_Color) {
+      nscolor colorIfVisited = paintIfVisited.mPaint.mColor;
+      nscolor colors[2] = { color, colorIfVisited };
+      color = nsStyleContext::CombineVisitedColors(colors,
+                                         aStyleContext->RelevantLinkVisited());
+    }
+  }
+
+  SetupCairoColor(aContext, color, aOpacity);
+}
+
 float
 nsSVGGeometryFrame::MaybeOptimizeOpacity(float aFillOrStrokeOpacity)
 {
@@ -223,14 +254,8 @@ nsSVGGeometryFrame::SetupCairoFill(gfxContext *aContext)
   // On failure, use the fallback colour in case we have an
   // objectBoundingBox where the width or height of the object is zero.
   // See http://www.w3.org/TR/SVG11/coords.html#ObjectBoundingBox
-  if (style->mFill.mType == eStyleSVGPaintType_Server) {
+  SetupFallbackOrPaintColor(aContext, GetStyleContext(),
-    SetupCairoColor(aContext,
+                            &nsStyleSVG::mFill, opacity);
-                    GetStyleSVG()->mFill.mFallbackColor,
-                    opacity);
-  } else
-    SetupCairoColor(aContext,
-                    GetStyleSVG()->mFill.mPaint.mColor,
-                    opacity);
 
   return PR_TRUE;
 }
@@ -314,14 +339,8 @@ nsSVGGeometryFrame::SetupCairoStroke(gfxContext *aContext)
   // On failure, use the fallback colour in case we have an
   // objectBoundingBox where the width or height of the object is zero.
   // See http://www.w3.org/TR/SVG11/coords.html#ObjectBoundingBox
-  if (style->mStroke.mType == eStyleSVGPaintType_Server) {
+  SetupFallbackOrPaintColor(aContext, GetStyleContext(),
-    SetupCairoColor(aContext,
+                            &nsStyleSVG::mStroke, opacity);
-                    GetStyleSVG()->mStroke.mFallbackColor,
-                    opacity);
-  } else
-    SetupCairoColor(aContext,
-                    GetStyleSVG()->mStroke.mPaint.mColor,
-                    opacity);
 
   return PR_TRUE;
 }