SceneManager.start will now reset the SceneSystems.sceneUpdate reference to NOOP. This gets set back to the Scene update method again during bootScene (if it has one) and stops errors with external plugins and multi-part files that may trigger update before create has been called. Fix phaserjs#4629

Author: photonstorm

src/scene/SceneManager.js

@@ -20,7 +20,7 @@ var Systems = require('./Systems');
  *
  * The Scene Manager is a Game level system, responsible for creating, processing and updating all of the
  * Scenes in a Game instance.
- *
+ó *
  *
  * @class SceneManager
  * @memberof Phaser.Scenes
@@ -1156,33 +1156,39 @@ var SceneManager = new Class({
 
         if (scene)
         {
+            var sys = scene.sys;
+
             //  If the Scene is already running (perhaps they called start from a launched sub-Scene?)
             //  then we close it down before starting it again.
-            if (scene.sys.isActive() || scene.sys.isPaused())
+            if (sys.isActive() || sys.isPaused())
             {
-                scene.sys.shutdown();
+                sys.shutdown();
 
-                scene.sys.start(data);
+                sys.sceneUpdate = NOOP;
+
+                sys.start(data);
             }
             else
             {
-                scene.sys.start(data);
+                sys.sceneUpdate = NOOP;
+
+                sys.start(data);
 
                 var loader;
 
-                if (scene.sys.load)
+                if (sys.load)
                 {
-                    loader = scene.sys.load;
+                    loader = sys.load;
                 }
 
                 //  Files payload?
-                if (loader && scene.sys.settings.hasOwnProperty('pack'))
+                if (loader && sys.settings.hasOwnProperty('pack'))
                 {
                     loader.reset();
 
-                    if (loader.addPack({ payload: scene.sys.settings.pack }))
+                    if (loader.addPack({ payload: sys.settings.pack }))
                     {
-                        scene.sys.settings.status = CONST.LOADING;
+                        sys.settings.status = CONST.LOADING;
 
                         loader.once(LoaderEvents.COMPLETE, this.payloadComplete, this);