Support edge-inclusive intersections in mapToVisibleRectInAncestorSpace

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

 /*
  * Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2007, 2008, 2009 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 330 matching lines @@
     // If the box is decorated or is overflowing, extend it to include the border-box and overflow.
     if (m_hasBoxDecorationBackground || hasOverflowModel()) {
         // The selectionRect can project outside of the overflowRect, so take their union
         // for paint invalidation to avoid selection painting glitches.
         LayoutRect decoratedPaintInvalidationRect = unionRect(localSelectionRect(), visualOverflowRect());
         paintInvalidationRect.unite(decoratedPaintInvalidationRect);
     }
 
     // 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.
 // Callers with local SVG viewport coordinates should first apply the localToBorderBoxTransform
 // to convert from SVG viewport coordinates to local CSS box coordinates.
 void LayoutSVGRoot::mapLocalToAncestor(const LayoutBoxModelObject* ancestor, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed, const PaintInvalidationState* paintInvalidationState) const
 {
     ASSERT(!(mode & IsFixed)); // We should have no fixed content in the SVG layout tree.
 
     LayoutReplaced::mapLocalToAncestor(ancestor, transformState, mode | ApplyContainerFlip, wasFixed, paintInvalidationState);
@@ skipping 45 matching lines @@
             updateHitTestResult(result, pointInBorderBox);
             if (result.addNodeToListBasedTestResult(node(), locationInContainer, boundsRect) == StopHitTesting)
                 return true;
         }
     }
 
     return false;
 }
 
 } // namespace blink