diff --git a/lib/ace/edit_session.js b/lib/ace/edit_session.js
index b6d107d8789..bc0a1ac9efc 100644
--- a/lib/ace/edit_session.js
+++ b/lib/ace/edit_session.js
@@ -148,6 +148,7 @@ var EditSession = function(text, mode) {
     this.$undoSelect = true;
 
     this.$foldData = [];
+    this.id = "session" + (++EditSession.$uid);
     this.$foldData.toString = function() {
         return this.join("\n");
     };
diff --git a/lib/ace/edit_session/folding.js b/lib/ace/edit_session/folding.js
index fbab03fa16b..4e67fe4509d 100644
--- a/lib/ace/edit_session/folding.js
+++ b/lib/ace/edit_session/folding.js
@@ -772,7 +772,7 @@ function Folding() {
                 this.removeFold(fold);
             else
                 this.expandFold(fold);
-            return;
+            return fold;
         }
 
         var range = this.getFoldWidgetRange(row, true);
@@ -781,7 +781,7 @@ function Folding() {
             fold = this.getFoldAt(range.start.row, range.start.column, 1);
             if (fold && range.isEqual(fold.range)) {
                 this.removeFold(fold);
-                return;
+                return fold;
             }
         }
         
diff --git a/lib/ace/ext/modelist.js b/lib/ace/ext/modelist.js
index daf6e31bba5..a708ae0ffb6 100644
--- a/lib/ace/ext/modelist.js
+++ b/lib/ace/ext/modelist.js
@@ -137,7 +137,7 @@ var supportedModes = {
     Protobuf:    ["proto"],
     Python:      ["py"],
     R:           ["r"],
-    Razor:       ["cshtml"],
+    Razor:       ["cshtml|asp"],
     RDoc:        ["Rd"],
     RHTML:       ["Rhtml"],
     RST:         ["rst"],
diff --git a/lib/ace/keyboard/textinput.js b/lib/ace/keyboard/textinput.js
index 1a57b2e6dfb..e3ceb31420c 100644
--- a/lib/ace/keyboard/textinput.js
+++ b/lib/ace/keyboard/textinput.js
@@ -364,10 +364,11 @@ var TextInput = function(parentNode, host) {
             return;
         // console.log("onCompositionStart", inComposition)
         inComposition = {};
+        inComposition.canUndo = host.session.$undoManager;
         host.onCompositionStart();
         setTimeout(onCompositionUpdate, 0);
         host.on("mousedown", onCompositionEnd);
-        if (!host.selection.isEmpty()) {
+        if (inComposition.canUndo && !host.selection.isEmpty()) {
             host.insert("");
             host.session.markUndoGroup();
             host.selection.clearSelection();
@@ -385,7 +386,8 @@ var TextInput = function(parentNode, host) {
         host.onCompositionUpdate(val);
         if (inComposition.lastValue)
             host.undo();
-        inComposition.lastValue = val;
+        if (inComposition.canUndo)
+            inComposition.lastValue = val;
         if (inComposition.lastValue) {
             var r = host.selection.getRange();
             host.insert(inComposition.lastValue);
diff --git a/lib/ace/lib/dom.js b/lib/ace/lib/dom.js
index 01cf66bb840..dfc32079d47 100644
--- a/lib/ace/lib/dom.js
+++ b/lib/ace/lib/dom.js
@@ -37,7 +37,7 @@ exports.getDocumentHead = function(doc) {
     if (!doc)
         doc = document;
     return doc.head || doc.getElementsByTagName("head")[0] || doc.documentElement;
-};
+}
 
 exports.createElement = function(tag, ns) {
     return document.createElementNS ?
@@ -46,7 +46,7 @@ exports.createElement = function(tag, ns) {
 };
 
 exports.hasCssClass = function(el, name) {
-    var classes = (el.className || "").split(/\s+/g);
+    var classes = (el.className + "").split(/\s+/g);
     return classes.indexOf(name) !== -1;
 };
 
diff --git a/lib/ace/lib/lang.js b/lib/ace/lib/lang.js
index 921dee1de10..61fe8e0c705 100644
--- a/lib/ace/lib/lang.js
+++ b/lib/ace/lib/lang.js
@@ -74,7 +74,7 @@ exports.copyArray = function(array){
     var copy = [];
     for (var i=0, l=array.length; i<l; i++) {
         if (array[i] && typeof array[i] == "object")
-            copy[i] = this.copyObject( array[i] );
+            copy[i] = this.copyObject(array[i]);
         else 
             copy[i] = array[i];
     }
@@ -92,14 +92,12 @@ exports.deepCopy = function deepCopy(obj) {
         }
         return copy;
     }
-    var cons = obj.constructor;
-    if (cons === RegExp)
+    if (Object.prototype.toString.call(obj) !== "[object Object]")
         return obj;
     
-    copy = cons();
-    for (var key in obj) {
+    copy = {};
+    for (var key in obj)
         copy[key] = deepCopy(obj[key]);
-    }
     return copy;
 };
 
diff --git a/lib/ace/line_widgets.js b/lib/ace/line_widgets.js
index 6eaffc8810d..83b0af94155 100644
--- a/lib/ace/line_widgets.js
+++ b/lib/ace/line_widgets.js
@@ -214,7 +214,7 @@ function LineWidgets(session) {
         if (!w.coverGutter) {
             w.el.style.zIndex = 3;
         }
-        if (!w.pixelHeight) {
+        if (w.pixelHeight == null) {
             w.pixelHeight = w.el.offsetHeight;
         }
         if (w.rowCount == null) {
diff --git a/lib/ace/mouse/default_gutter_handler.js b/lib/ace/mouse/default_gutter_handler.js
index d70d0c0a3d7..db35a5085bc 100644
--- a/lib/ace/mouse/default_gutter_handler.js
+++ b/lib/ace/mouse/default_gutter_handler.js
@@ -88,6 +88,7 @@ function GutterHandler(mouseHandler) {
 
         tooltip.setHtml(tooltipAnnotation);
         tooltip.show();
+        editor._signal("showGutterTooltip", tooltip);
         editor.on("mousewheel", hideTooltip);
 
         if (mouseHandler.$tooltipFollowsMouse) {
@@ -107,6 +108,7 @@ function GutterHandler(mouseHandler) {
         if (tooltipAnnotation) {
             tooltip.hide();
             tooltipAnnotation = null;
+            editor._signal("hideGutterTooltip", tooltip);
             editor.removeEventListener("mousewheel", hideTooltip);
         }
     }
diff --git a/lib/ace/virtual_renderer.js b/lib/ace/virtual_renderer.js
index 6b8d08423e3..2482cc7d38d 100644
--- a/lib/ace/virtual_renderer.js
+++ b/lib/ace/virtual_renderer.js
@@ -245,6 +245,7 @@ var VirtualRenderer = function(container, theme) {
         
         this.$loop.schedule(this.CHANGE_FULL);
         this.session.$setFontMetrics(this.$fontMetrics);
+        this.scrollBarV.scrollLeft = this.scrollBarV.scrollTop = null;
         
         this.onChangeNewLineMode = this.onChangeNewLineMode.bind(this);
         this.onChangeNewLineMode()