reset undo stack after setValue() calls

lib/ace/edit_session.js

@@ -94,8 +94,9 @@ var EditSession = function(text, mode) {
     };
 
     this.setValue = function(text) {
-      this.doc.setValue(text);
-      this.$deltas = [];
+        this.doc.setValue(text);
+        this.$deltas = [];
+        this.$undoManager.reset();
     };
 
     this.getValue =
@@ -130,7 +131,8 @@ var EditSession = function(text, mode) {
 
     this.$defaultUndoManager = {
         undo: function() {},
-        redo: function() {}
+        redo: function() {},
+        reset: function() {}
     };
 
     this.getUndoManager = function() {

lib/ace/undomanager.js

@@ -38,8 +38,7 @@
 define(function(require, exports, module) {
 
 var UndoManager = function() {
-    this.$undoStack = [];
-    this.$redoStack = [];
+    this.reset();
 };
 
 (function() {
@@ -65,6 +64,11 @@ var UndoManager = function() {
             this.$undoStack.push(deltas);
         }
     };
+    
+    this.reset = function() {
+        this.$undoStack = [];
+        this.$redoStack = [];
+    };
 
 }).call(UndoManager.prototype);