diff --git a/lib/ace/config.js b/lib/ace/config.js
index 4a7dc286..97a18954 100644
--- a/lib/ace/config.js
+++ b/lib/ace/config.js
@@ -93,22 +93,37 @@ exports.setModuleUrl = function(name, subst) {
     return options.$moduleUrls[name] = subst;
 };
 
+exports.$loading = {};
 exports.loadModule = function(moduleName, onLoad) {
     var module, moduleType;
     if (Array.isArray(moduleName)) {
         moduleType = moduleName[0];
         moduleName = moduleName[1];
     }
+
     try {
         module = require(moduleName);
     } catch (e) {};
-    if (module)
+    // require(moduleName) can return empty object if called after require([moduleName], callback)
+    if (module && !exports.$loading[moduleName])
         return onLoad && onLoad(module);
 
+    if (!exports.$loading[moduleName])
+        exports.$loading[moduleName] = [];
+
+    exports.$loading[moduleName].push(onLoad);
+
+    if (exports.$loading[moduleName].length > 1)
+        return;
+
     var afterLoad = function() {
         require([moduleName], function(module) {
             exports._emit("load.module", {name: moduleName, module: module});
-            onLoad && onLoad(module);
+            var listeners = exports.$loading[moduleName];
+            exports.$loading[moduleName] = null;
+            listeners.forEach(function(onLoad) {
+                onLoad && onLoad(module);
+            });
         });
     };
 
diff --git a/lib/ace/lib/event_emitter.js b/lib/ace/lib/event_emitter.js
index a359a9a7..5e4f6ec1 100644
--- a/lib/ace/lib/event_emitter.js
+++ b/lib/ace/lib/event_emitter.js
@@ -79,11 +79,10 @@ EventEmitter._signal = function(eventName, e) {
 
 EventEmitter.once = function(eventName, callback) {
     var _self = this;
-    var newCallback = function() {
-        fun && fun.apply(null, arguments);
-        _self.removeEventListener(event, newCallback);
-    };
-    this.addEventListener(event, newCallback);
+    callback && this.addEventListener(eventName, function newCallback() {
+        _self.removeEventListener(eventName, newCallback);
+        callback.apply(null, arguments);
+    });
 };
 
 
diff --git a/lib/ace/mouse/mouse_handler.js b/lib/ace/mouse/mouse_handler.js
index 74fc4872..4ff31b2f 100644
--- a/lib/ace/mouse/mouse_handler.js
+++ b/lib/ace/mouse/mouse_handler.js
@@ -121,6 +121,7 @@ var MouseHandler = function(editor) {
                 renderer.$moveTextAreaToCursor();
             }
             self.isMousePressed = false;
+            self.onMouseEvent("mouseup", e)
         };
 
         var onCaptureInterval = function() {
diff --git a/lib/ace/mouse/multi_select_handler.js b/lib/ace/mouse/multi_select_handler.js
index 8a6e2a11..2e0cda7b 100644
--- a/lib/ace/mouse/multi_select_handler.js
+++ b/lib/ace/mouse/multi_select_handler.js
@@ -106,7 +106,7 @@ function onMouseDown(e) {
 
         var oldRange = selection.rangeList.rangeAtPoint(pos);
 
-        event.capture(editor.container, function(){}, function() {
+        editor.once("mouseup", function() {
             var tmpSel = selection.toOrientedRange();
 
             if (oldRange && tmpSel.isEmpty() && isSamePoint(oldRange.cursor, tmpSel.cursor))
diff --git a/lib/ace/multi_select.js b/lib/ace/multi_select.js
index ee41f98a..fc07bd76 100644
--- a/lib/ace/multi_select.js
+++ b/lib/ace/multi_select.js
@@ -831,14 +831,10 @@ exports.onSessionChange = function(e) {
 
     var oldSession = e.oldSession;
     if (oldSession) {
-        // todo use events
-        if (oldSession.multiSelect && oldSession.multiSelect.editor == this)
-            oldSession.multiSelect.editor = null;
-
-        session.multiSelect.removeEventListener("addRange", this.$onAddRange);
-        session.multiSelect.removeEventListener("removeRange", this.$onRemoveRange);
-        session.multiSelect.removeEventListener("multiSelect", this.$onMultiSelect);
-        session.multiSelect.removeEventListener("singleSelect", this.$onSingleSelect);
+        oldSession.multiSelect.removeEventListener("addRange", this.$onAddRange);
+        oldSession.multiSelect.removeEventListener("removeRange", this.$onRemoveRange);
+        oldSession.multiSelect.removeEventListener("multiSelect", this.$onMultiSelect);
+        oldSession.multiSelect.removeEventListener("singleSelect", this.$onSingleSelect);
     }
 
     session.multiSelect.on("addRange", this.$onAddRange);
diff --git a/lib/ace/virtual_renderer.js b/lib/ace/virtual_renderer.js
index 775d16e6..a76ec222 100644
--- a/lib/ace/virtual_renderer.js
+++ b/lib/ace/virtual_renderer.js
@@ -326,6 +326,9 @@ var VirtualRenderer = function(container, theme) {
                 changes = changes | this.CHANGE_FULL;
         }
 
+        if (!this.$size.scrollerHeight)
+            return;
+
         if (force)
             this.$renderChanges(changes, true);
         else
@@ -1265,6 +1268,8 @@ var VirtualRenderer = function(container, theme) {
         }
 
         function afterLoad(theme) {
+            if (!theme.cssClass)
+                return;
             dom.importCssString(
                 theme.cssText,
                 theme.cssClass,