Have ElementData::attributeItem() return a reference

Source/core/dom/ElementData.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 48 matching lines @@
     void setIdForStyleResolution(const AtomicString& newId) const { m_idForStyleResolution = newId; }
 
     const StylePropertySet* inlineStyle() const { return m_inlineStyle.get(); }
 
     const StylePropertySet* presentationAttributeStyle() const;
 
     // This is not a trivial getter and its return value should be cached for performance.
     size_t length() const;
     bool isEmpty() const { return !length(); }
 
-    const Attribute* attributeItem(unsigned index) const;
+    const Attribute& attributeItem(unsigned index) const;
     const Attribute* getAttributeItem(const QualifiedName&) const;
     size_t getAttributeItemIndex(const QualifiedName&, bool shouldIgnoreCase = false) const;
     size_t getAttributeItemIndex(const AtomicString& name, bool shouldIgnoreAttributeCase) const;
     size_t getAttrIndex(Attr*) const;
 
     bool hasID() const { return !m_idForStyleResolution.isNull(); }
     bool hasClass() const { return !m_classNames.isNull(); }
 
     bool isEquivalent(const ElementData* other) const;
 
@@ skipping 62 matching lines @@
 // attribute will have the same inline style.
 class UniqueElementData FINAL : public ElementData {
 public:
     static PassRefPtr<UniqueElementData> create();
     PassRefPtr<ShareableElementData> makeShareableCopy() const;
 
     // These functions do no error/duplicate checking.
     void addAttribute(const QualifiedName&, const AtomicString&);
     void removeAttribute(size_t index);
 
-    Attribute* attributeItem(unsigned index);
+    Attribute& attributeItem(unsigned index);
     Attribute* getAttributeItem(const QualifiedName&);
 
     UniqueElementData();
     explicit UniqueElementData(const ShareableElementData&);
     explicit UniqueElementData(const UniqueElementData&);
 
     // FIXME: We might want to support sharing element data for elements with
     // presentation attribute style. Lots of table cells likely have the same
     // attributes. Most modern pages don't use presentation attributes though
     // so this might not make sense.
@@ skipping 19 matching lines @@
 {
     if (!m_isUnique)
         return 0;
     return static_cast<const UniqueElementData*>(this)->m_presentationAttributeStyle.get();
 }
 
 inline const Attribute* ElementData::getAttributeItem(const AtomicString& name, bool shouldIgnoreAttributeCase) const
 {
     size_t index = getAttributeItemIndex(name, shouldIgnoreAttributeCase);
     if (index != kNotFound)
-        return attributeItem(index);
+        return &attributeItem(index);
     return 0;
 }
 
 inline const Attribute* ElementData::attributeBase() const
 {
     if (m_isUnique)
         return static_cast<const UniqueElementData*>(this)->m_attributeVector.begin();
     return static_cast<const ShareableElementData*>(this)->m_attributeArray;
 }
 
@@ skipping 42 matching lines @@
     const Attribute* begin = attributeBase();
     unsigned length = this->length();
     for (unsigned i = 0; i < length; ++i) {
         const Attribute& attribute = begin[i];
         if (attribute.name().matches(name))
             return &attribute;
     }
     return 0;
 }
 
-inline const Attribute* ElementData::attributeItem(unsigned index) const
+inline const Attribute& ElementData::attributeItem(unsigned index) const
 {
     RELEASE_ASSERT(index < length());
-    return attributeBase() + index;
+    ASSERT(attributeBase() + index);
+    return *(attributeBase() + index);
 }
 
 inline void UniqueElementData::addAttribute(const QualifiedName& attributeName, const AtomicString& value)
 {
     m_attributeVector.append(Attribute(attributeName, value));
 }
 
 inline void UniqueElementData::removeAttribute(size_t index)
 {
     m_attributeVector.remove(index);
 }
 
-inline Attribute* UniqueElementData::attributeItem(unsigned index)
+inline Attribute& UniqueElementData::attributeItem(unsigned index)
 {
-    return &m_attributeVector.at(index);
+    return m_attributeVector.at(index);
 }
 
 } // namespace WebCore
 
 #endif // ElementData_h