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


git-svn-id: svn://10.0.0.236/trunk@94654 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/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);