From 4483598166a708aeecbbaec7ff7b46b8130b6c8a Mon Sep 17 00:00:00 2001
From: Fabian Jakobs <fabian.jakobs@web.de>
Date: Tue, 4 May 2010 11:41:28 +0200
Subject: [PATCH] add additional checks

---
 src/ace/Document.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/ace/Document.js b/src/ace/Document.js
index 2df8ae7b..93a68f3d 100644
--- a/src/ace/Document.js
+++ b/src/ace/Document.js
@@ -304,6 +304,9 @@ ace.Document = function(text, mode) {
     };
 
     this.$insertLines = function(row, lines) {
+        if (lines.length == 0)
+            return;
+
         var args = [row, 0];
         args.push.apply(args, lines);
         this.lines.splice.apply(this.lines, args);
@@ -320,6 +323,9 @@ ace.Document = function(text, mode) {
     },
 
     this.$insert = function(position, text, fromUndo) {
+        if (text.length == 0)
+            return;
+
         this.modified = true;
         if (this.lines.length <= 1) {
             this.$detectNewLine(text);
@@ -383,6 +389,9 @@ ace.Document = function(text, mode) {
     };
 
     this.remove = function(range, fromUndo) {
+        if (range.isEmpty())
+            return;
+
         this.$remove(range, fromUndo);
 
         this.fireChangeEvent(range.start.row,
@@ -393,6 +402,9 @@ ace.Document = function(text, mode) {
     };
 
     this.$remove = function(range, fromUndo) {
+        if (range.isEmpty())
+            return;
+
         if (!fromUndo && this.$undoManager) {
             var nl = this.$getNewLineCharacter();
             this.$deltas.push({