Bug 737724 - make IsDefunct() inline, r=surkov, f=tbsaunde

accessible/src/base/nsAccessNode.cpp

@@ -116,12 +116,6 @@ void nsAccessNode::LastRelease()
 ////////////////////////////////////////////////////////////////////////////////
 // nsAccessNode public
 
-bool
-nsAccessNode::IsDefunct() const
-{
-  return !mContent;
-}
-
 bool
 nsAccessNode::Init()
 {
@@ -218,7 +212,7 @@ void nsAccessNode::ShutdownXPAccessibility()
 // nsAccessNode protected
 nsPresContext* nsAccessNode::GetPresContext()
 {
-  if (IsDefunct())
+  if (!mDoc)
     return nsnull;
 
   nsIPresShell* presShell(mDoc->PresShell());
@@ -262,7 +256,7 @@ nsAccessNode::IsPrimaryForNode() const
 void
 nsAccessNode::ScrollTo(PRUint32 aScrollType)
 {
-  if (IsDefunct())
+  if (!mDoc)
     return;
 
   nsIPresShell* shell = mDoc->PresShell();
@@ -288,7 +282,7 @@ nsAccessNode::Language(nsAString& aLanguage)
 {
   aLanguage.Truncate();
 
-  if (IsDefunct())
+  if (!mDoc)
     return;
 
   nsCoreUtils::GetLanguageFor(mContent, nsnull, aLanguage);

accessible/src/base/nsAccessNode.h

@@ -105,11 +105,6 @@ public:
    */
   virtual void Shutdown();
 
-  /**
-   * Returns true when the accessible is defunct.
-   */
-  virtual bool IsDefunct() const;
-
   /**
    * Return frame for the given access node object.
    */

accessible/src/base/nsAccessible.cpp

@@ -2519,8 +2519,10 @@ nsAccessible::AppendTextTo(nsAString& aText, PRUint32 aStartOffset,
 void
 nsAccessible::Shutdown()
 {
-  // Invalidate the child count and pointers to other accessibles, also make
-  // sure none of its children point to this parent
+  // Mark the accessible as defunct, invalidate the child count and pointers to 
+  // other accessibles, also make sure none of its children point to this parent
+  mFlags |= eIsDefunct;
+
   InvalidateChildren();
   if (mParent)
     mParent->RemoveChild(this);

accessible/src/base/nsAccessible.h

@@ -643,6 +643,11 @@ public:
    */
   static void TranslateString(const nsAString& aKey, nsAString& aStringOut);
 
+  /**
+   * Return true if the accessible is defunct.
+   */
+  bool IsDefunct() const { return mFlags & eIsDefunct; }
+
 protected:
 
   //////////////////////////////////////////////////////////////////////////////
@@ -687,25 +692,33 @@ protected:
     { mFlags = (mFlags & ~kChildrenFlagsMask) | aFlag; }
 
   /**
-   * Flags describing the accessible itself.
+   * Flags used to describe the state of this accessible.
    * @note keep these flags in sync with ChildrenFlags
    */
+  enum StateFlags {
+    eIsDefunct = 1 << 2 // accessible is defunct
+  };
+
+  /**
+   * Flags describing the type of this accessible.
+   * @note keep these flags in sync with ChildrenFlags and StateFlags
+   */
   enum AccessibleTypes {
-    eApplicationAccessible = 1 << 2,
-    eAutoCompleteAccessible = 1 << 3,
-    eAutoCompletePopupAccessible = 1 << 4,
-    eComboboxAccessible = 1 << 5,
-    eDocAccessible = 1 << 6,
-    eHyperTextAccessible = 1 << 7,
-    eHTMLFileInputAccessible = 1 << 8,
-    eHTMLListItemAccessible = 1 << 9,
-    eImageAccessible = 1 << 10,
-    eImageMapAccessible = 1 << 11,
-    eListControlAccessible = 1 << 12,
-    eMenuButtonAccessible = 1 << 13,
-    eMenuPopupAccessible = 1 << 14,
-    eRootAccessible = 1 << 15,
-    eTextLeafAccessible = 1 << 16
+    eApplicationAccessible = 1 << 3,
+    eAutoCompleteAccessible = 1 << 4,
+    eAutoCompletePopupAccessible = 1 << 5,
+    eComboboxAccessible = 1 << 6,
+    eDocAccessible = 1 << 7,
+    eHyperTextAccessible = 1 << 8,
+    eHTMLFileInputAccessible = 1 << 9,
+    eHTMLListItemAccessible = 1 << 10,
+    eImageAccessible = 1 << 11,
+    eImageMapAccessible = 1 << 12,
+    eListControlAccessible = 1 << 13,
+    eMenuButtonAccessible = 1 << 14,
+    eMenuPopupAccessible = 1 << 15,
+    eRootAccessible = 1 << 16,
+    eTextLeafAccessible = 1 << 17
   };
 
   //////////////////////////////////////////////////////////////////////////////

accessible/src/base/nsApplicationAccessible.cpp

@@ -309,12 +309,6 @@ nsApplicationAccessible::GetPlatformVersion(nsAString& aVersion)
 ////////////////////////////////////////////////////////////////////////////////
 // nsAccessNode public methods
 
-bool
-nsApplicationAccessible::IsDefunct() const
-{
-  return nsAccessibilityService::IsShutdown();
-}
-
 bool
 nsApplicationAccessible::Init()
 {

accessible/src/base/nsApplicationAccessible.h

@@ -98,7 +98,6 @@ public:
   NS_DECL_NSIACCESSIBLEAPPLICATION
 
   // nsAccessNode
-  virtual bool IsDefunct() const;
   virtual bool Init();
   virtual void Shutdown();
   virtual bool IsPrimaryForNode() const;

accessible/src/base/nsDocAccessible.cpp

@@ -693,12 +693,6 @@ nsDocAccessible::GetFrame() const
   return root;
 }
 
-bool
-nsDocAccessible::IsDefunct() const
-{
-  return nsHyperTextAccessibleWrap::IsDefunct() || !mDocument;
-}
-
 // nsDocAccessible protected member
 void nsDocAccessible::GetBoundsRect(nsRect& aBounds, nsIFrame** aRelativeFrame)
 {

accessible/src/base/nsDocAccessible.h

@@ -116,7 +116,6 @@ public:
   virtual bool Init();
   virtual void Shutdown();
   virtual nsIFrame* GetFrame() const;
-  virtual bool IsDefunct() const;
   virtual nsINode* GetNode() const { return mDocument; }
   virtual nsIDocument* GetDocumentNode() const { return mDocument; }
 

accessible/src/msaa/nsAccessNodeWrap.cpp

@@ -215,10 +215,11 @@ __try{
   *aNodeName = nsnull;
   *aNodeValue = nsnull;
 
-  if (IsDefunct())
+  nsINode* node = GetNode();
+  if (!node)
     return E_FAIL;
 
-  nsCOMPtr<nsIDOMNode> DOMNode(do_QueryInterface(GetNode()));
+  nsCOMPtr<nsIDOMNode> DOMNode(do_QueryInterface(node));
 
   PRUint16 nodeType = 0;
   DOMNode->GetNodeType(&nodeType);
@@ -244,7 +245,7 @@ __try{
   // data nodes in their internal object model.
   *aUniqueID = - NS_PTR_TO_INT32(UniqueID());
 
-  *aNumChildren = GetNode()->GetChildCount();
+  *aNumChildren = node->GetChildCount();
 
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
   return S_OK;
@@ -262,7 +263,7 @@ STDMETHODIMP nsAccessNodeWrap::get_attributes(
 __try{
   *aNumAttribs = 0;
 
-  if (IsDefunct() || IsDocumentNode())
+  if (!mContent || IsDocumentNode())
     return E_FAIL;
 
   PRUint32 numAttribs = mContent->GetAttrCount();
@@ -293,7 +294,7 @@ STDMETHODIMP nsAccessNodeWrap::get_attributesForNames(
     /* [length_is][size_is][retval] */ BSTR __RPC_FAR *aAttribValues)
 {
 __try {
-  if (IsDefunct() || !IsElement())
+  if (!mContent || !IsElement())
     return E_FAIL;
 
   nsCOMPtr<nsIDOMElement> domElement(do_QueryInterface(mContent));
@@ -335,7 +336,7 @@ STDMETHODIMP nsAccessNodeWrap::get_computedStyle(
 __try{
   *aNumStyleProperties = 0;
 
-  if (IsDefunct() || IsDocumentNode())
+  if (!mContent || IsDocumentNode())
     return E_FAIL;
 
   nsCOMPtr<nsIDOMCSSStyleDeclaration> cssDecl =
@@ -370,7 +371,7 @@ STDMETHODIMP nsAccessNodeWrap::get_computedStyleForProperties(
     /* [length_is][size_is][out] */ BSTR __RPC_FAR *aStyleValues)
 {
 __try {
-  if (IsDefunct() || IsDocumentNode())
+  if (!mContent || IsDocumentNode())
     return E_FAIL;
  
   nsCOMPtr<nsIDOMCSSStyleDeclaration> cssDecl =
@@ -442,10 +443,11 @@ nsAccessNodeWrap::MakeAccessNode(nsINode *aNode)
 STDMETHODIMP nsAccessNodeWrap::get_parentNode(ISimpleDOMNode __RPC_FAR *__RPC_FAR *aNode)
 {
 __try {
-  if (IsDefunct())
+  nsINode* node = GetNode();
+  if (!node)
     return E_FAIL;
 
-  *aNode = MakeAccessNode(GetNode()->GetNodeParent());
+  *aNode = MakeAccessNode(node->GetNodeParent());
 
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 
@@ -455,10 +457,11 @@ __try {
 STDMETHODIMP nsAccessNodeWrap::get_firstChild(ISimpleDOMNode __RPC_FAR *__RPC_FAR *aNode)
 {
 __try {
-  if (IsDefunct())
+  nsINode* node = GetNode();
+  if (!node)
     return E_FAIL;
 
-  *aNode = MakeAccessNode(GetNode()->GetFirstChild());
+  *aNode = MakeAccessNode(node->GetFirstChild());
 
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 
@@ -468,10 +471,11 @@ __try {
 STDMETHODIMP nsAccessNodeWrap::get_lastChild(ISimpleDOMNode __RPC_FAR *__RPC_FAR *aNode)
 {
 __try {
-  if (IsDefunct())
+  nsINode* node = GetNode();
+  if (!node)
     return E_FAIL;
 
-  *aNode = MakeAccessNode(GetNode()->GetLastChild());
+  *aNode = MakeAccessNode(node->GetLastChild());
 
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 
@@ -481,10 +485,11 @@ __try {
 STDMETHODIMP nsAccessNodeWrap::get_previousSibling(ISimpleDOMNode __RPC_FAR *__RPC_FAR *aNode)
 {
 __try {
-  if (IsDefunct())
+  nsINode* node = GetNode();
+  if (!node)
     return E_FAIL;
 
-  *aNode = MakeAccessNode(GetNode()->GetPreviousSibling());
+  *aNode = MakeAccessNode(node->GetPreviousSibling());
 
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 
@@ -494,10 +499,11 @@ __try {
 STDMETHODIMP nsAccessNodeWrap::get_nextSibling(ISimpleDOMNode __RPC_FAR *__RPC_FAR *aNode)
 {
 __try {
-  if (IsDefunct())
+  nsINode* node = GetNode();
+  if (!node)
     return E_FAIL;
 
-  *aNode = MakeAccessNode(GetNode()->GetNextSibling());
+  *aNode = MakeAccessNode(node->GetNextSibling());
 
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 
@@ -511,10 +517,11 @@ nsAccessNodeWrap::get_childAt(unsigned aChildIndex,
 __try {
   *aNode = nsnull;
 
-  if (IsDefunct())
+  nsINode* node = GetNode();
+  if (!node)
     return E_FAIL;
 
-  *aNode = MakeAccessNode(GetNode()->GetChildAt(aChildIndex));
+  *aNode = MakeAccessNode(node->GetChildAt(aChildIndex));
 
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 

accessible/src/xul/nsXULTreeAccessible.cpp

@@ -124,6 +124,9 @@ nsXULTreeAccessible::NativeState()
   state |= states::READONLY;
 
   // multiselectable state.
+  if (!mTreeView)
+    return state;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   NS_ENSURE_TRUE(selection, state);
@@ -145,7 +148,7 @@ nsXULTreeAccessible::GetValue(nsAString& aValue)
 
   aValue.Truncate();
 
-  if (IsDefunct())
+  if (IsDefunct() || !mTreeView)
     return NS_ERROR_FAILURE;
 
   nsCOMPtr<nsITreeSelection> selection;
@@ -173,12 +176,6 @@ nsXULTreeAccessible::GetValue(nsAString& aValue)
 ////////////////////////////////////////////////////////////////////////////////
 // nsXULTreeAccessible: nsAccessNode implementation
 
-bool
-nsXULTreeAccessible::IsDefunct() const
-{
-  return nsAccessibleWrap::IsDefunct() || !mTree || !mTreeView;
-}
-
 void
 nsXULTreeAccessible::Shutdown()
 {
@@ -270,6 +267,9 @@ nsXULTreeAccessible::IsSelect()
 nsAccessible*
 nsXULTreeAccessible::CurrentItem()
 {
+  if (!mTreeView)
+    return nsnull;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (selection) {
@@ -291,6 +291,9 @@ nsXULTreeAccessible::SetCurrentItem(nsAccessible* aItem)
 already_AddRefed<nsIArray>
 nsXULTreeAccessible::SelectedItems()
 {
+  if (!mTreeView)
+    return nsnull;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (!selection)
@@ -321,6 +324,9 @@ nsXULTreeAccessible::SelectedItems()
 PRUint32
 nsXULTreeAccessible::SelectedItemCount()
 {
+  if (!mTreeView)
+    return 0;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (selection) {
@@ -335,6 +341,9 @@ nsXULTreeAccessible::SelectedItemCount()
 bool
 nsXULTreeAccessible::AddItemToSelection(PRUint32 aIndex)
 {
+  if (!mTreeView)
+    return false;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (selection) {
@@ -351,6 +360,9 @@ nsXULTreeAccessible::AddItemToSelection(PRUint32 aIndex)
 bool
 nsXULTreeAccessible::RemoveItemFromSelection(PRUint32 aIndex)
 {
+  if (!mTreeView)
+    return false;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (selection) {
@@ -367,6 +379,9 @@ nsXULTreeAccessible::RemoveItemFromSelection(PRUint32 aIndex)
 bool
 nsXULTreeAccessible::IsItemSelected(PRUint32 aIndex)
 {
+  if (!mTreeView)
+    return false;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (selection) {
@@ -380,6 +395,9 @@ nsXULTreeAccessible::IsItemSelected(PRUint32 aIndex)
 bool
 nsXULTreeAccessible::UnselectAll()
 {
+  if (!mTreeView)
+    return false;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (!selection)
@@ -392,6 +410,9 @@ nsXULTreeAccessible::UnselectAll()
 nsAccessible*
 nsXULTreeAccessible::GetSelectedItem(PRUint32 aIndex)
 {
+  if (!mTreeView)
+    return nsnull;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (!selection)
@@ -418,6 +439,9 @@ bool
 nsXULTreeAccessible::SelectAll()
 {
   // see if we are multiple select if so set ourselves as such
+  if (!mTreeView)
+    return false;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   if (selection) {
@@ -453,8 +477,8 @@ nsXULTreeAccessible::GetChildCount()
 {
   // tree's children count is row count + treecols count.
   PRInt32 childCount = nsAccessible::GetChildCount();
-  if (childCount == -1)
-    return -1;
+  if (childCount == -1 || !mTreeView)
+    return childCount;
 
   PRInt32 rowCount = 0;
   mTreeView->GetRowCount(&rowCount);
@@ -536,7 +560,7 @@ nsXULTreeAccessible::ContainerWidget() const
 nsAccessible*
 nsXULTreeAccessible::GetTreeItemAccessible(PRInt32 aRow)
 {
-  if (aRow < 0 || IsDefunct())
+  if (aRow < 0 || IsDefunct() || !mTreeView)
     return nsnull;
 
   PRInt32 rowCount = 0;
@@ -793,7 +817,7 @@ nsXULTreeItemAccessibleBase::GetBounds(PRInt32 *aX, PRInt32 *aY,
 NS_IMETHODIMP
 nsXULTreeItemAccessibleBase::SetSelected(bool aSelect)
 {
-  if (IsDefunct())
+  if (IsDefunct() || !mTreeView)
     return NS_ERROR_FAILURE;
 
   nsCOMPtr<nsITreeSelection> selection;
@@ -811,7 +835,7 @@ nsXULTreeItemAccessibleBase::SetSelected(bool aSelect)
 NS_IMETHODIMP
 nsXULTreeItemAccessibleBase::TakeFocus()
 {
-  if (IsDefunct())
+  if (IsDefunct() || !mTreeView)
     return NS_ERROR_FAILURE;
 
   nsCOMPtr<nsITreeSelection> selection;
@@ -826,10 +850,13 @@ nsXULTreeItemAccessibleBase::TakeFocus()
 Relation
 nsXULTreeItemAccessibleBase::RelationByType(PRUint32 aType)
 {
+  if (!mTreeView)
+    return Relation();
+
   if (aType != nsIAccessibleRelation::RELATION_NODE_CHILD_OF)
     return Relation();
 
-    PRInt32 parentIndex;
+  PRInt32 parentIndex = -1;
   if (!NS_SUCCEEDED(mTreeView->GetParentIndex(mRow, &parentIndex)))
     return Relation();
 
@@ -890,12 +917,6 @@ nsXULTreeItemAccessibleBase::DoAction(PRUint8 aIndex)
 ////////////////////////////////////////////////////////////////////////////////
 // nsXULTreeItemAccessibleBase: nsAccessNode implementation
 
-bool
-nsXULTreeItemAccessibleBase::IsDefunct() const
-{
-  return nsAccessibleWrap::IsDefunct() || !mTree || !mTreeView || mRow < 0;
-}
-
 void
 nsXULTreeItemAccessibleBase::Shutdown()
 {
@@ -930,7 +951,7 @@ nsXULTreeItemAccessibleBase::GroupPosition(PRInt32 *aGroupLevel,
   NS_ENSURE_ARG_POINTER(aPositionInGroup);
   *aPositionInGroup = 0;
 
-  if (IsDefunct())
+  if (IsDefunct() || !mTreeView)
     return NS_ERROR_FAILURE;
 
   PRInt32 level;
@@ -978,6 +999,9 @@ nsXULTreeItemAccessibleBase::GroupPosition(PRInt32 *aGroupLevel,
 PRUint64
 nsXULTreeItemAccessibleBase::NativeState()
 {
+  if (!mTreeView)
+    return states::DEFUNCT;
+
   // focusable and selectable states
   PRUint64 state = states::FOCUSABLE | states::SELECTABLE;
 
@@ -1075,6 +1099,9 @@ nsXULTreeItemAccessibleBase::GetSiblingAtOffset(PRInt32 aOffset,
 bool
 nsXULTreeItemAccessibleBase::IsExpandable()
 {
+  if (!mTreeView)
+    return false;
+
   bool isContainer = false;
   mTreeView->IsContainer(mRow, &isContainer);
   if (isContainer) {
@@ -1100,6 +1127,9 @@ void
 nsXULTreeItemAccessibleBase::GetCellName(nsITreeColumn* aColumn,
                                          nsAString& aName)
 {
+  if (!mTreeView)
+    return;
+
   mTreeView->GetCellText(mRow, aColumn, aName);
 
   // If there is still no name try the cell value:
@@ -1164,12 +1194,6 @@ nsXULTreeItemAccessible::GetName(nsAString& aName)
 ////////////////////////////////////////////////////////////////////////////////
 // nsXULTreeItemAccessible: nsAccessNode implementation
 
-bool
-nsXULTreeItemAccessible::IsDefunct() const
-{
-  return nsXULTreeItemAccessibleBase::IsDefunct() || !mColumn;
-}
-
 bool
 nsXULTreeItemAccessible::Init()
 {

accessible/src/xul/nsXULTreeAccessible.h

@@ -78,7 +78,6 @@ public:
   NS_IMETHOD GetValue(nsAString& aValue);
 
   // nsAccessNode
-  virtual bool IsDefunct() const;
   virtual void Shutdown();
 
   // nsAccessible
@@ -204,7 +203,6 @@ public:
   NS_IMETHOD DoAction(PRUint8 aIndex);
 
   // nsAccessNode
-  virtual bool IsDefunct() const;
   virtual void Shutdown();
   virtual bool IsPrimaryForNode() const;
 
@@ -287,7 +285,6 @@ public:
   NS_IMETHOD GetName(nsAString& aName);
 
   // nsAccessNode
-  virtual bool IsDefunct() const;
   virtual bool Init();
   virtual void Shutdown();
 

accessible/src/xul/nsXULTreeGridAccessible.cpp

@@ -93,15 +93,18 @@ nsXULTreeGridAccessible::GetColumnCount(PRInt32 *aColumnCount)
 }
 
 NS_IMETHODIMP
-nsXULTreeGridAccessible::GetRowCount(PRInt32 *arowCount)
+nsXULTreeGridAccessible::GetRowCount(PRInt32* aRowCount)
 {
-  NS_ENSURE_ARG_POINTER(arowCount);
-  *arowCount = nsnull;
+  NS_ENSURE_ARG_POINTER(aRowCount);
+  *aRowCount = 0;
 
   if (IsDefunct())
     return NS_ERROR_FAILURE;
 
-  return mTreeView->GetRowCount(arowCount);
+  if (!mTreeView)
+    return NS_OK;
+
+  return mTreeView->GetRowCount(aRowCount);
 }
 
 NS_IMETHODIMP
@@ -176,6 +179,9 @@ nsXULTreeGridAccessible::GetSelectedCells(nsIArray **aCells)
   NS_ENSURE_ARG_POINTER(aCells);
   *aCells = nsnull;
 
+  if (!mTreeView)
+    return NS_OK;
+
   nsCOMPtr<nsIMutableArray> selCells = do_CreateInstance(NS_ARRAY_CONTRACTID);
   NS_ENSURE_TRUE(selCells, NS_ERROR_FAILURE);
 
@@ -220,6 +226,9 @@ nsXULTreeGridAccessible::GetSelectedCellIndices(PRUint32 *aCellsCount,
   NS_ENSURE_ARG_POINTER(aCells);
   *aCells = nsnull;
 
+  if (!mTreeView)
+    return NS_OK;
+
   PRInt32 selectedrowCount = 0;
   nsresult rv = GetSelectionCount(&selectedrowCount);
   NS_ENSURE_SUCCESS(rv, rv);
@@ -309,6 +318,9 @@ nsXULTreeGridAccessible::GetSelectedRowIndices(PRUint32 *arowCount,
   if (IsDefunct())
     return NS_ERROR_FAILURE;
 
+  if (!mTreeView)
+    return NS_OK;
+
   PRInt32 selectedrowCount = 0;
   nsresult rv = GetSelectionCount(&selectedrowCount);
   NS_ENSURE_SUCCESS(rv, rv);
@@ -515,6 +527,9 @@ nsXULTreeGridAccessible::IsRowSelected(PRInt32 aRowIndex, bool *aIsSelected)
   if (IsDefunct())
     return NS_ERROR_FAILURE;
 
+  if (!mTreeView)
+    return NS_ERROR_INVALID_ARG;
+
   nsCOMPtr<nsITreeSelection> selection;
   nsresult rv = mTreeView->GetSelection(getter_AddRefs(selection));
   NS_ENSURE_SUCCESS(rv, rv);
@@ -532,6 +547,9 @@ nsXULTreeGridAccessible::IsCellSelected(PRInt32 aRowIndex, PRInt32 aColumnIndex,
 NS_IMETHODIMP
 nsXULTreeGridAccessible::SelectRow(PRInt32 aRowIndex)
 {
+  if (!mTreeView)
+    return NS_ERROR_INVALID_ARG;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   NS_ENSURE_STATE(selection);
@@ -548,6 +566,9 @@ nsXULTreeGridAccessible::SelectColumn(PRInt32 aColumnIndex)
 NS_IMETHODIMP
 nsXULTreeGridAccessible::UnselectRow(PRInt32 aRowIndex)
 {
+  if (!mTreeView)
+    return NS_ERROR_INVALID_ARG;
+
   nsCOMPtr<nsITreeSelection> selection;
   mTreeView->GetSelection(getter_AddRefs(selection));
   NS_ENSURE_STATE(selection);
@@ -854,7 +875,7 @@ nsXULTreeGridCellAccessible::GetName(nsAString& aName)
 {
   aName.Truncate();
 
-  if (IsDefunct())
+  if (IsDefunct() || !mTreeView)
     return NS_ERROR_FAILURE;
 
   mTreeView->GetCellText(mRow, mColumn, aName);
@@ -936,7 +957,7 @@ nsXULTreeGridCellAccessible::GetActionName(PRUint8 aIndex, nsAString& aName)
   if (aIndex != eAction_Click)
     return NS_ERROR_INVALID_ARG;
 
-  if (IsDefunct())
+  if (IsDefunct() || !mTreeView)
     return NS_ERROR_FAILURE;
 
   bool isCycler = false;
@@ -1103,7 +1124,7 @@ nsXULTreeGridCellAccessible::IsSelected(bool *aIsSelected)
   NS_ENSURE_ARG_POINTER(aIsSelected);
   *aIsSelected = false;
 
-  if (IsDefunct())
+  if (IsDefunct() || !mTreeView)
     return NS_ERROR_FAILURE;
 
   nsCOMPtr<nsITreeSelection> selection;
@@ -1116,17 +1137,10 @@ nsXULTreeGridCellAccessible::IsSelected(bool *aIsSelected)
 ////////////////////////////////////////////////////////////////////////////////
 // nsXULTreeGridCellAccessible: nsAccessNode implementation
 
-bool
-nsXULTreeGridCellAccessible::IsDefunct() const
-{
-  return nsLeafAccessible::IsDefunct() || !mParent || !mTree || !mTreeView ||
-    !mColumn;
-}
-
 bool
 nsXULTreeGridCellAccessible::Init()
 {
-  if (!nsLeafAccessible::Init())
+  if (!nsLeafAccessible::Init() || !mTreeView)
     return false;
 
   PRInt16 type;
@@ -1196,6 +1210,9 @@ nsXULTreeGridCellAccessible::NativeRole()
 PRUint64
 nsXULTreeGridCellAccessible::NativeState()
 {
+  if (!mTreeView)
+    return states::DEFUNCT;
+
   // selectable/selected state
   PRUint64 states = states::SELECTABLE;
 
@@ -1255,6 +1272,9 @@ nsXULTreeGridCellAccessible::GetColumnIndex() const
 void
 nsXULTreeGridCellAccessible::CellInvalidated()
 {
+  if (!mTreeView)
+    return;
+
   nsAutoString textEquiv;
 
   PRInt16 type;
@@ -1326,6 +1346,9 @@ nsXULTreeGridCellAccessible::DispatchClickEvent(nsIContent *aContent,
 bool
 nsXULTreeGridCellAccessible::IsEditable() const
 {
+  if (!mTreeView)
+    return false;
+
   // XXX: logic corresponds to tree.xml, it's preferable to have interface
   // method to check it.
   bool isEditable = false;

accessible/src/xul/nsXULTreeGridAccessible.h

@@ -161,7 +161,6 @@ public:
   NS_DECL_NSIACCESSIBLETABLECELL
 
   // nsAccessNode
-  virtual bool IsDefunct() const;
   virtual bool Init();
   virtual bool IsPrimaryForNode() const;