Reland "Let SVGForeignObject's local SVG coordinates mean what it should"

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

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) Research In Motion Limited 2010. 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 81 matching lines @@
                                   : DescendantIsolationNeedsUpdate);
   }
 
   LayoutBlock::styleDidChange(diff, oldStyle);
   SVGResourcesCache::clientStyleChanged(this, diff, styleRef());
 }
 
 void LayoutSVGBlock::mapLocalToAncestor(const LayoutBoxModelObject* ancestor,
                                         TransformState& transformState,
                                         MapCoordinatesFlags flags) const {
+  // Convert from local HTML coordinates to local SVG coordinates.
+  transformState.move(locationOffset());
+  // Apply other mappings on local SVG coordinates.
   SVGLayoutSupport::mapLocalToAncestor(this, ancestor, transformState, flags);
 }
 
 void LayoutSVGBlock::mapAncestorToLocal(const LayoutBoxModelObject* ancestor,
                                         TransformState& transformState,
                                         MapCoordinatesFlags flags) const {
   if (this == ancestor)
     return;
 
+  // Map to local SVG coordinates.
   SVGLayoutSupport::mapAncestorToLocal(*this, ancestor, transformState, flags);
+  // Convert from local SVG coordinates to local HTML coordinates.
+  transformState.move(locationOffset());

[Xianzhu, 2017/03/28 17:45:09]

This is the fix. In the original patch, this was "-locationOffset()". The
TransformState is already in UnapplyInverseTransformDirection mode for
mapAncestorToLocal(), so we should just apply transforms and offsets in the
normal direction.

 }
 
 const LayoutObject* LayoutSVGBlock::pushMappingToContainer(
     const LayoutBoxModelObject* ancestorToStopAt,
     LayoutGeometryMap& geometryMap) const {
+  // Convert from local HTML coordinates to local SVG coordinates.
+  geometryMap.push(this, locationOffset());
+  // Apply other mappings on local SVG coordinates.
   return SVGLayoutSupport::pushMappingToContainer(this, ancestorToStopAt,
                                                   geometryMap);
 }
 
 LayoutRect LayoutSVGBlock::absoluteVisualRect() const {
   return SVGLayoutSupport::visualRectInAncestorSpace(*this, *view());
 }
 
 bool LayoutSVGBlock::mapToVisualRectInAncestorSpaceInternal(
     const LayoutBoxModelObject* ancestor,
     TransformState& transformState,
     VisualRectFlags) const {
   transformState.flatten();
   LayoutRect rect(transformState.lastPlanarQuad().boundingBox());
+  // Convert from local HTML coordinates to local SVG coordinates.
+  rect.moveBy(location());
+  // Apply other mappings on local SVG coordinates.
   bool retval = SVGLayoutSupport::mapToVisualRectInAncestorSpace(
       *this, ancestor, FloatRect(rect), rect);
   transformState.setQuad(FloatQuad(FloatRect(rect)));
   return retval;
 }
 
 bool LayoutSVGBlock::nodeAtPoint(HitTestResult&,
                                  const HitTestLocation&,
                                  const LayoutPoint&,
                                  HitTestAction) {
   NOTREACHED();
   return false;
 }
 
 }  // namespace blink