Don't drop type information returned from locateRenderSVGTextAncestor

Source/core/layout/svg/LayoutSVGText.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2006 Alexander Kellett <lypanov@kde.org>
  * Copyright (C) 2006 Oliver Hunt <ojh16@student.canterbury.ac.nz>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved.
  * Copyright (C) 2012 Google Inc.
  *
@@ skipping 36 matching lines @@
 #include "core/svg/SVGTransformList.h"
 #include "core/svg/SVGURIReference.h"
 #include "platform/FloatConversion.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/fonts/SimpleFontData.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/TransformState.h"
 
 namespace blink {
 
+namespace {
+
+const LayoutSVGText* findTextRoot(const LayoutObject* start)
+{
+    ASSERT(start);
+    for (; start; start = start->parent()) {
+        if (start->isSVGText())
+            return toLayoutSVGText(start);
+    }
+    return nullptr;
+}
+
+}
+
 LayoutSVGText::LayoutSVGText(SVGTextElement* node)
     : LayoutSVGBlock(node)
     , m_needsReordering(false)
     , m_needsPositioningValuesUpdate(false)
     , m_needsTransformUpdate(true)
     , m_needsTextMetricsUpdate(false)
 {
 }
 
 LayoutSVGText::~LayoutSVGText()
 {
     ASSERT(m_layoutAttributes.isEmpty());
 }
 
 bool LayoutSVGText::isChildAllowed(LayoutObject* child, const ComputedStyle&) const
 {
     return child->isSVGInline() || (child->isText() && SVGLayoutSupport::isLayoutableTextNode(child));
 }
 
 LayoutSVGText* LayoutSVGText::locateLayoutSVGTextAncestor(LayoutObject* start)
 {
-    ASSERT(start);
-    while (start && !start->isSVGText())
-        start = start->parent();
-    if (!start || !start->isSVGText())
-        return nullptr;
-    return toLayoutSVGText(start);
+    return const_cast<LayoutSVGText*>(findTextRoot(start));
 }
 
 const LayoutSVGText* LayoutSVGText::locateLayoutSVGTextAncestor(const LayoutObject* start)
 {
-    ASSERT(start);
-    while (start && !start->isSVGText())
-        start = start->parent();
-    if (!start || !start->isSVGText())
-        return nullptr;
-    return toLayoutSVGText(start);
+    return findTextRoot(start);
 }
 
 static inline void collectLayoutAttributes(LayoutObject* text, Vector<SVGTextLayoutAttributes*>& attributes)
 {
     for (LayoutObject* descendant = text; descendant; descendant = descendant->nextInPreOrder(text)) {
         if (descendant->isSVGInlineText())
             attributes.append(toLayoutSVGInlineText(descendant)->layoutAttributes());
     }
 }
 
@@ skipping 402 matching lines @@
     SVGResourcesCache::clientWillBeRemovedFromTree(child);
 
     Vector<SVGTextLayoutAttributes*, 2> affectedAttributes;
     FontCachePurgePreventer fontCachePurgePreventer;
     subtreeChildWillBeRemoved(child, affectedAttributes);
     LayoutSVGBlock::removeChild(child);
     subtreeChildWasRemoved(affectedAttributes);
 }
 
 }