From 3e6be1cbe76a165bfff367cd88fa4968968035e7 Mon Sep 17 00:00:00 2001
From: "dholbert@cs.stanford.edu" <dholbert@cs.stanford.edu>
Date: Mon, 19 Nov 2007 18:01:19 -0800
Subject: [PATCH] Bug 391178 - Avoid walking frame tree when destroying
 nsTreeColFrame.  r+sr=roc, a=blocking1.9+

---
 layout/xul/base/src/tree/src/nsTreeColFrame.cpp | 16 +++++++++++++---
 layout/xul/base/src/tree/src/nsTreeColFrame.h   |  2 +-
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/layout/xul/base/src/tree/src/nsTreeColFrame.cpp b/layout/xul/base/src/tree/src/nsTreeColFrame.cpp
index 8f8f26baeafa..5b72ba8bff3c 100644
--- a/layout/xul/base/src/tree/src/nsTreeColFrame.cpp
+++ b/layout/xul/base/src/tree/src/nsTreeColFrame.cpp
@@ -45,6 +45,7 @@
 #include "nsIDOMNSDocument.h"
 #include "nsIDocument.h"
 #include "nsIBoxObject.h"
+#include "nsTreeBoxObject.h"
 #include "nsIDOMElement.h"
 #include "nsITreeBoxObject.h"
 #include "nsITreeColumns.h"
@@ -99,7 +100,7 @@ nsTreeColFrame::Init(nsIContent*      aContent,
 void                                                                
 nsTreeColFrame::Destroy()                          
 {
-  InvalidateColumns();
+  InvalidateColumns(PR_FALSE);
   nsBoxFrame::Destroy();
 }
 
@@ -220,12 +221,21 @@ nsTreeColFrame::GetTreeBoxObject()
 }
 
 void
-nsTreeColFrame::InvalidateColumns()
+nsTreeColFrame::InvalidateColumns(PRBool aCanWalkFrameTree)
 {
   nsITreeBoxObject* treeBoxObject = GetTreeBoxObject();
   if (treeBoxObject) {
     nsCOMPtr<nsITreeColumns> columns;
-    treeBoxObject->GetColumns(getter_AddRefs(columns));
+
+    if (aCanWalkFrameTree) {
+      treeBoxObject->GetColumns(getter_AddRefs(columns));
+    } else {
+      nsITreeBoxObject* body =
+        static_cast<nsTreeBoxObject*>(treeBoxObject)->GetCachedTreeBody();
+      if (body) {
+        body->GetColumns(getter_AddRefs(columns));
+      }
+    }
 
     if (columns)
       columns->InvalidateColumns();
diff --git a/layout/xul/base/src/tree/src/nsTreeColFrame.h b/layout/xul/base/src/tree/src/nsTreeColFrame.h
index 570676872bbf..26bf02604179 100644
--- a/layout/xul/base/src/tree/src/nsTreeColFrame.h
+++ b/layout/xul/base/src/tree/src/nsTreeColFrame.h
@@ -89,5 +89,5 @@ protected:
    * Helper method that gets the nsITreeColumns object this column belongs to
    * and calls InvalidateColumns() on it.
    */
-  void InvalidateColumns();
+  void InvalidateColumns(PRBool aCanWalkFrameTree = PR_TRUE);
 };