Fix for bug #75305: Doing Undo and Redo crashes browser

Added nsAutoUpdateViewBatch class, and use it in
nsPlaintexteditor::Undo()/Redo().

    editor/base/nsEditorUtils.h
    editor/base/nsPlaintextEditor.cpp

r=jfrancis@netscape.com   sr=sfraser@netscape.com

editor/base/nsEditorUtils.h

@@ -144,6 +144,31 @@ class nsAutoTxnsConserveSelection
   PRBool mOldState;
 };
 
+/***************************************************************************
+ * stack based helper class for batching reflow and paint requests.
+ */
+class nsAutoUpdateViewBatch
+{
+  public:
+  
+  nsAutoUpdateViewBatch(nsEditor *ed) : mEd(ed)
+  {
+    NS_ASSERTION(mEd, "null mEd pointer!");
+
+    if (mEd) 
+      mEd->BeginUpdateViewBatch();
+  }
+  
+  ~nsAutoUpdateViewBatch() 
+  {
+    if (mEd) 
+      mEd->EndUpdateViewBatch();
+  }
+  
+  protected:
+  nsEditor *mEd;
+};
+
 /******************************************************************************
  * some helper classes for iterating the dom tree
  *****************************************************************************/

editor/base/nsPlaintextEditor.cpp

@@ -1301,6 +1301,8 @@ nsPlaintextEditor::SetWrapWidth(PRInt32 aWrapColumn)
 NS_IMETHODIMP 
 nsPlaintextEditor::Undo(PRUint32 aCount)
 {
+  nsAutoUpdateViewBatch beginViewBatching(this);
+
   ForceCompositionEnd();
   nsresult result = NS_OK;
 
@@ -1327,6 +1329,7 @@ nsPlaintextEditor::Redo(PRUint32 aCount)
 {
   nsresult result = NS_OK;
 
+  nsAutoUpdateViewBatch beginViewBatching(this);
   nsAutoRules beginRulesSniffing(this, kOpRedo, nsIEditor::eNone);
 
   nsTextRulesInfo ruleInfo(nsTextEditRules::kRedo);

editor/libeditor/base/nsEditorUtils.h

@@ -144,6 +144,31 @@ class nsAutoTxnsConserveSelection
   PRBool mOldState;
 };
 
+/***************************************************************************
+ * stack based helper class for batching reflow and paint requests.
+ */
+class nsAutoUpdateViewBatch
+{
+  public:
+  
+  nsAutoUpdateViewBatch(nsEditor *ed) : mEd(ed)
+  {
+    NS_ASSERTION(mEd, "null mEd pointer!");
+
+    if (mEd) 
+      mEd->BeginUpdateViewBatch();
+  }
+  
+  ~nsAutoUpdateViewBatch() 
+  {
+    if (mEd) 
+      mEd->EndUpdateViewBatch();
+  }
+  
+  protected:
+  nsEditor *mEd;
+};
+
 /******************************************************************************
  * some helper classes for iterating the dom tree
  *****************************************************************************/

editor/libeditor/text/nsPlaintextEditor.cpp

@@ -1301,6 +1301,8 @@ nsPlaintextEditor::SetWrapWidth(PRInt32 aWrapColumn)
 NS_IMETHODIMP 
 nsPlaintextEditor::Undo(PRUint32 aCount)
 {
+  nsAutoUpdateViewBatch beginViewBatching(this);
+
   ForceCompositionEnd();
   nsresult result = NS_OK;
 
@@ -1327,6 +1329,7 @@ nsPlaintextEditor::Redo(PRUint32 aCount)
 {
   nsresult result = NS_OK;
 
+  nsAutoUpdateViewBatch beginViewBatching(this);
   nsAutoRules beginRulesSniffing(this, kOpRedo, nsIEditor::eNone);
 
   nsTextRulesInfo ruleInfo(nsTextEditRules::kRedo);