Support edge-inclusive intersections in mapToVisibleRectInAncestorSpace

third_party/WebKit/Source/core/layout/svg/LayoutSVGRoot.cpp

Index: third_party/WebKit/Source/core/layout/svg/LayoutSVGRoot.cpp
diff --git a/third_party/WebKit/Source/core/layout/svg/LayoutSVGRoot.cpp b/third_party/WebKit/Source/core/layout/svg/LayoutSVGRoot.cpp
index 3380513a74a27304b088a1eb25d50dd26dc5031a..5f3a18518421c41949a1ecba958c1b99b9a7a178 100644
--- a/third_party/WebKit/Source/core/layout/svg/LayoutSVGRoot.cpp
+++ b/third_party/WebKit/Source/core/layout/svg/LayoutSVGRoot.cpp
@@ -348,20 +348,26 @@ LayoutRect LayoutSVGRoot::clippedOverflowRectForPaintInvalidation(const LayoutBo
 
     // Compute the paint invalidation rect in the parent coordinate space.
     LayoutRect rect(enclosingIntRect(paintInvalidationRect));
-    LayoutReplaced::mapToVisibleRectInAncestorSpace(paintInvalidationContainer, rect, paintInvalidationState);
+    LayoutReplaced::mapToVisibleRectInAncestorSpace(paintInvalidationContainer, rect, paintInvalidationState, false);
     return rect;
 }
 
-void LayoutSVGRoot::mapToVisibleRectInAncestorSpace(const LayoutBoxModelObject* ancestor, LayoutRect& rect, const PaintInvalidationState* paintInvalidationState) const
+bool LayoutSVGRoot::mapToVisibleRectInAncestorSpace(const LayoutBoxModelObject* ancestor, LayoutRect& rect, const PaintInvalidationState* paintInvalidationState, int flags) const
 {
     // Note that we don't apply the border-box transform here - it's assumed
     // that whoever called us has done that already.
 
     // Apply initial viewport clip
-    if (shouldApplyViewportClip())
-        rect.intersect(LayoutRect(pixelSnappedBorderBoxRect()));
+    if (shouldApplyViewportClip()) {
+        if (flags & EdgeInclusive) {
+            if (!rect.inclusiveIntersect(LayoutRect(pixelSnappedBorderBoxRect())))
+                return false;
+        } else {
+            rect.intersect(LayoutRect(pixelSnappedBorderBoxRect()));

[chrishtr, 2016/03/22 17:25:49]

early out?

[szager1, 2016/03/22 19:42:24]

I'm hesitant to do that, because the call to
LayoutReplaced::mapToVisibleRectInAncestorSpace dispatches to
LayoutBox::mapVisibleRectToAncestorSpace, which does this at the top:

inflatePaintInvalidationRectForReflectionAndFilter(rect);

I'm concerned that this could take a zero-area rect and expand it to a non-zero
rect.  So an early out here might be incorrect behavior.

+        }
+    }
 
-    LayoutReplaced::mapToVisibleRectInAncestorSpace(ancestor, rect, paintInvalidationState);
+    return LayoutReplaced::mapToVisibleRectInAncestorSpace(ancestor, rect, paintInvalidationState, flags);
 }
 
 // This method expects local CSS box coordinates.