From cb79193effb61471611a2a540ca21d9dc21cf10d Mon Sep 17 00:00:00 2001
From: Julian Viereck <julian.viereck@gmail.com>
Date: Tue, 11 Jan 2011 09:13:03 +0100
Subject: [PATCH] Don't perform a replace operation in Document.replace if
 there is nothing to replace. Increases performance in wrapMode if inserting
 many lines

---
 lib/ace/document.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/ace/document.js b/lib/ace/document.js
index be1563a7..2138f234 100644
--- a/lib/ace/document.js
+++ b/lib/ace/document.js
@@ -688,6 +688,16 @@ var Document = function(text, mode) {
     },
 
     this.replace = function(range, text) {
+        // Shortcut: Nothing to replace in this case.
+        if (text.length == 0 && range.isEmpty()) {
+            return range.start;
+        } else
+        // Shortcut: If the text we want to insert is the same as it is already
+        // in the document, we don't have to replace anything.
+        if (text == this.getTextRange(range)) {
+            return range.end;
+        }
+
         this.$remove(range);
         if (text) {
             var end = this.$insert(range.start, text);