diff --git a/cocos2d-x/cocos/audio/AudioEngine.cpp b/cocos2d-x/cocos/audio/AudioEngine.cpp
index 588c7010..5913b473 100644
--- a/cocos2d-x/cocos/audio/AudioEngine.cpp
+++ b/cocos2d-x/cocos/audio/AudioEngine.cpp
@@ -360,6 +360,7 @@ void AudioEngine::onPause(const CustomEvent &event) {
         if (it->second.state == AudioState::PLAYING)
         {
             _audioEngineImpl->pause(it->first);
+            it->second.state = AudioState::PAUSED;
             _breakAudioID.push_back(it->first);
         }
     }
@@ -374,7 +375,12 @@ void AudioEngine::onPause(const CustomEvent &event) {
 void AudioEngine::onResume(const CustomEvent &event) {
     auto itEnd = _breakAudioID.end();
     for (auto it = _breakAudioID.begin(); it != itEnd; ++it) {
-        _audioEngineImpl->resume(*it);
+        auto iter = _audioIDInfoMap.find(*it);
+        if (iter != _audioIDInfoMap.end() && iter->second.state == AudioState::PAUSED)
+        {
+            _audioEngineImpl->resume(*it);
+            iter->second.state = AudioState::PLAYING;
+        }
     }
     _breakAudioID.clear();
     
diff --git a/cocos2d-x/cocos/cocos2d.cpp b/cocos2d-x/cocos/cocos2d.cpp
index 8d9b7713..b551baff 100644
--- a/cocos2d-x/cocos/cocos2d.cpp
+++ b/cocos2d-x/cocos/cocos2d.cpp
@@ -32,7 +32,7 @@ NS_CC_BEGIN
 
 CC_DLL const char* cocos2dVersion()
 {
-    return "2.4.9";
+    return "2.4.10-rc.1";
 }
 
 NS_CC_END
diff --git a/cocos2d-x/cocos/network/WebSocket-libwebsockets.cpp b/cocos2d-x/cocos/network/WebSocket-libwebsockets.cpp
index 9de360e4..e9297aab 100644
--- a/cocos2d-x/cocos/network/WebSocket-libwebsockets.cpp
+++ b/cocos2d-x/cocos/network/WebSocket-libwebsockets.cpp
@@ -853,7 +853,10 @@ void WebSocketImpl::close()
 
 void WebSocketImpl::closeAsync(int code, const std::string &reason)
 {
-    lws_close_reason(_wsInstance, (lws_close_status)code, (unsigned char*)const_cast<char*>(reason.c_str()), reason.length());
+    if (_wsInstance) 
+    {
+        lws_close_reason(_wsInstance, (lws_close_status)code, (unsigned char*)const_cast<char*>(reason.c_str()), reason.length());
+    }
     closeAsync();
 }
 
diff --git a/cocos2d-x/cocos/platform/android/java/src/org/cocos2dx/lib/Cocos2dxHelper.java b/cocos2d-x/cocos/platform/android/java/src/org/cocos2dx/lib/Cocos2dxHelper.java
index 43827c5d..70fb379e 100644
--- a/cocos2d-x/cocos/platform/android/java/src/org/cocos2dx/lib/Cocos2dxHelper.java
+++ b/cocos2d-x/cocos/platform/android/java/src/org/cocos2dx/lib/Cocos2dxHelper.java
@@ -46,6 +46,7 @@ import android.os.Build;
 import android.os.Environment;
 import android.os.ParcelFileDescriptor;
 import android.os.Vibrator;
+import android.os.LocaleList;
 import android.preference.PreferenceManager.OnActivityResultListener;
 import android.util.DisplayMetrics;
 import android.util.Log;
@@ -304,11 +305,19 @@ public class Cocos2dxHelper {
     }
 
     public static String getCurrentLanguage() {
-        return Locale.getDefault().getLanguage();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            return LocaleList.getDefault().get(0).getLanguage();
+        } else {
+            return Locale.getDefault().getLanguage();
+        }
     }
 
     public static String getCurrentLanguageCode() {
-        return Locale.getDefault().toString();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            return LocaleList.getDefault().get(0).getLanguage();
+        } else {
+            return Locale.getDefault().getLanguage();
+        }
     }
 
     public static String getDeviceModel(){
diff --git a/cocos2d-x/cocos/scripting/js-bindings/manual/jsb_websocket.cpp b/cocos2d-x/cocos/scripting/js-bindings/manual/jsb_websocket.cpp
index e09b7071..575f020b 100644
--- a/cocos2d-x/cocos/scripting/js-bindings/manual/jsb_websocket.cpp
+++ b/cocos2d-x/cocos/scripting/js-bindings/manual/jsb_websocket.cpp
@@ -478,13 +478,32 @@ static bool WebSocket_close(se::State& s)
     }
     else if (argc == 2)
     {
-        assert(args[0].isNumber());
-        assert(args[1].isString());
-        int reasonCode;
-        std::string reasonString;
-        seval_to_int32(args[0], &reasonCode);
-        seval_to_std_string(args[1], &reasonString);
-        cobj->closeAsync(reasonCode, reasonString);
+        if (args[0].isNumber()) {
+            int reasonCode;
+            if (args[1].isString()) {
+                std::string reasonString;
+                seval_to_int32(args[0], &reasonCode);
+                seval_to_std_string(args[1], &reasonString);
+                cobj->closeAsync(reasonCode, reasonString);
+            } else if (args[1].isNullOrUndefined()) {
+                seval_to_int32(args[0], &reasonCode);
+                cobj->closeAsync(reasonCode, "no_reason");
+            } else {
+                assert(false);
+            }
+        } else if (args[0].isNullOrUndefined()) {
+            if (args[1].isString()) {
+                std::string reasonString;
+                seval_to_std_string(args[1], &reasonString);
+                cobj->closeAsync(1005, reasonString);
+            } else if (args[1].isNullOrUndefined()) {
+                cobj->closeAsync();
+            } else {
+                assert(false);
+            }
+        } else {
+            assert(false);
+        }
     }
     else 
     {
diff --git a/cocos2d-x/package.json b/cocos2d-x/package.json
index 4c88c6f4..3e548cb5 100644
--- a/cocos2d-x/package.json
+++ b/cocos2d-x/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cocos2d-x-lite",
-  "version": "2.4.9",
+  "version": "2.4.10-rc.1",
   "description": "Cocos2d-x, compact version",
   "main": "gulpfile.js",
   "devDependencies": {
diff --git a/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml b/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml
index 0a990736..b5770593 100755
--- a/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml
+++ b/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml
@@ -25,7 +25,6 @@
             android:label="@string/app_name"
             android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
             android:launchMode="singleTask"
-            android:taskAffinity=""
             android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
diff --git a/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java b/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java
index 2eb59547..2550d2be 100755
--- a/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java
+++ b/cocos2d-x/templates/js-template-default/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java
@@ -37,15 +37,6 @@ public class AppActivity extends Cocos2dxActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        // Workaround in
-        // https://stackoverflow.com/questions/16283079/re-launch-of-activity-on-home-button-but-only-the-first-time/16447508
-        if (!isTaskRoot()) {
-            // Android launched another instance of the root activity into an existing task
-            // so just quietly finish and go away, dropping the user back into the activity
-            // at the top of the stack (ie: the last state of this task)
-            // Don't need to finish it again since it's finished in super.onCreate .
-            return;
-        }
         // DO OTHER INITIALIZATION BELOW
         SDKWrapper.getInstance().init(this);
 
diff --git a/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml b/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml
index da9874ac..1d92adee 100755
--- a/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml
+++ b/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/AndroidManifest.xml
@@ -25,7 +25,6 @@
             android:label="@string/app_name"
             android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
             android:launchMode="singleTask"
-            android:taskAffinity="" 
             android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
diff --git a/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java b/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java
index 2eb59547..2550d2be 100755
--- a/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java
+++ b/cocos2d-x/templates/js-template-link/frameworks/runtime-src/proj.android-studio/app/src/org/cocos2dx/javascript/AppActivity.java
@@ -37,15 +37,6 @@ public class AppActivity extends Cocos2dxActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        // Workaround in
-        // https://stackoverflow.com/questions/16283079/re-launch-of-activity-on-home-button-but-only-the-first-time/16447508
-        if (!isTaskRoot()) {
-            // Android launched another instance of the root activity into an existing task
-            // so just quietly finish and go away, dropping the user back into the activity
-            // at the top of the stack (ie: the last state of this task)
-            // Don't need to finish it again since it's finished in super.onCreate .
-            return;
-        }
         // DO OTHER INITIALIZATION BELOW
         SDKWrapper.getInstance().init(this);
 
diff --git a/engine/README.md b/engine/README.md
index 43328c9d..06af0884 100644
--- a/engine/README.md
+++ b/engine/README.md
@@ -148,6 +148,6 @@ For details below:
 
 * [Official site](https://www.cocos.com/products#CocosCreator)
 * [Download](https://www.cocos.com/creator)
-* [Documentation](https://docs.cocos.com/creator/manual/)
-* [API References](https://docs.cocos.com/creator/api/)
+* [Documentation](https://docs.cocos.com/creator/2.4/manual/)
+* [API References](https://docs.cocos.com/creator/2.4/api/)
 * [Forum](https://discuss.cocos2d-x.org/c/creator)
diff --git a/engine/api.d.ts b/engine/api.d.ts
index e8e3210a..5d10c070 100644
--- a/engine/api.d.ts
+++ b/engine/api.d.ts
@@ -1,10 +1,21 @@
-
-declare let CC_JSB: boolean
-declare let CC_NATIVERENDERER: boolean
-declare let CC_EDITOR: boolean
-declare let CC_PREVIEW: boolean
-declare let CC_TEST: boolean
-declare let CC_DEBUG: boolean
+/** Running in the editor. */
+declare const CC_EDITOR: boolean;
+/** Preview in browser or simulator. */
+declare const CC_PREVIEW: boolean;
+/** Running in the editor or preview. */
+declare const CC_DEV: boolean;
+/** Running in the editor or preview, or build in debug mode. */
+declare const CC_DEBUG: boolean;
+/** Running in published project. */
+declare const CC_BUILD: boolean;
+/** Running in native platforms (mobile app, desktop app, or simulator). */
+declare const CC_JSB: boolean;
+/** Running in runtime environments. */
+declare const CC_RUNTIME: boolean;
+/** Running in the engine's unit test. */
+declare const CC_TEST: boolean;
+/** Running in the WeChat Mini Game. */
+declare const CC_WECHATGAME: boolean;
 
 declare let cc: {
     // polyfills: {
diff --git a/engine/cocos2d/actions/tween.js b/engine/cocos2d/actions/tween.js
index 0d947ef7..d3246ab5 100644
--- a/engine/cocos2d/actions/tween.js
+++ b/engine/cocos2d/actions/tween.js
@@ -218,7 +218,7 @@ Tween.stopAllByTarget = function (target) {
  * Insert an action or tween to this sequence
  * !#zh
  * 插入一个 action 或者 tween 到队列中
- * @method then 
+ * @method then
  * @param {Action|Tween} other
  * @return {Tween}
  * @typescript then(other: Action|Tween<T>): Tween<T>
@@ -294,6 +294,7 @@ Tween.prototype.start = function () {
 Tween.prototype.stop = function () {
     if (this._finalAction) {
         cc.director.getActionManager().removeAction(this._finalAction);
+        this._finalAction = null;
     }
     return this;
 };
@@ -414,7 +415,7 @@ Object.assign(Tween.prototype, {
      */
     flipX () {
         return this.call(() => { this._target.scaleX *= -1; }, this);
-        
+
     },
     /**
      * !#en Flips target's scaleY
@@ -703,4 +704,4 @@ cc.tween = function (target) {
 };
 
 cc.Tween = Tween;
-  
+
diff --git a/engine/cocos2d/core/CCDirector.js b/engine/cocos2d/core/CCDirector.js
index 5178401d..af4739f1 100644
--- a/engine/cocos2d/core/CCDirector.js
+++ b/engine/cocos2d/core/CCDirector.js
@@ -845,7 +845,7 @@ cc.Director.prototype = {
 
         // Update
         if (!this._paused) {
-            this.emit(cc.Director.EVENT_BEFORE_UPDATE);
+            this.emit(cc.Director.EVENT_BEFORE_UPDATE, deltaTime);
 
             this._compScheduler.startPhase();
             this._compScheduler.updatePhase(deltaTime);
@@ -856,15 +856,15 @@ cc.Director.prototype = {
 
             this._compScheduler.lateUpdatePhase(deltaTime);
 
-            this.emit(cc.Director.EVENT_AFTER_UPDATE);
+            this.emit(cc.Director.EVENT_AFTER_UPDATE, deltaTime);
         }
 
         // Render
-        this.emit(cc.Director.EVENT_BEFORE_DRAW);
+        this.emit(cc.Director.EVENT_BEFORE_DRAW, deltaTime);
         renderer.render(this._scene, deltaTime);
         
         // After draw
-        this.emit(cc.Director.EVENT_AFTER_DRAW);
+        this.emit(cc.Director.EVENT_AFTER_DRAW, deltaTime);
 
         this._totalFrames++;
 
@@ -877,35 +877,36 @@ cc.Director.prototype = {
             // calculate "global" dt
             this.calculateDeltaTime(now);
 
+            const deltaTime = this._deltaTime;
             // Update
             if (!this._paused) {
                 // before update
-                this.emit(cc.Director.EVENT_BEFORE_UPDATE);
+                this.emit(cc.Director.EVENT_BEFORE_UPDATE, deltaTime);
 
                 // Call start for new added components
                 this._compScheduler.startPhase();
 
                 // Update for components
-                this._compScheduler.updatePhase(this._deltaTime);
+                this._compScheduler.updatePhase(deltaTime);
                 // Engine update with scheduler
-                this._scheduler.update(this._deltaTime);
+                this._scheduler.update(deltaTime);
 
                 // Late update for components
-                this._compScheduler.lateUpdatePhase(this._deltaTime);
+                this._compScheduler.lateUpdatePhase(deltaTime);
 
                 // User can use this event to do things after update
-                this.emit(cc.Director.EVENT_AFTER_UPDATE);
+                this.emit(cc.Director.EVENT_AFTER_UPDATE, deltaTime);
                 
                 // Destroy entities that have been removed recently
                 Obj._deferredDestroy();
             }
 
             // Render
-            this.emit(cc.Director.EVENT_BEFORE_DRAW);
-            renderer.render(this._scene, this._deltaTime);
+            this.emit(cc.Director.EVENT_BEFORE_DRAW, deltaTime);
+            renderer.render(this._scene, deltaTime);
 
             // After draw
-            this.emit(cc.Director.EVENT_AFTER_DRAW);
+            this.emit(cc.Director.EVENT_AFTER_DRAW, deltaTime);
 
             eventManager.frameUpdateListeners();
             this._totalFrames++;
diff --git a/engine/cocos2d/core/asset-manager/cache-manager.ts b/engine/cocos2d/core/asset-manager/cache-manager.ts
index c1bb9876..5577867b 100644
--- a/engine/cocos2d/core/asset-manager/cache-manager.ts
+++ b/engine/cocos2d/core/asset-manager/cache-manager.ts
@@ -149,6 +149,7 @@ export abstract class CacheManager {
      * 通过原始 url 移除缓存
      * 
      * @method removeCache
+     * @param {string} originUrl
      */
     public abstract removeCache (originUrl: string): void;
 }
diff --git a/engine/cocos2d/core/asset-manager/deprecated.js b/engine/cocos2d/core/asset-manager/deprecated.js
index e94d779a..1d85b4d5 100644
--- a/engine/cocos2d/core/asset-manager/deprecated.js
+++ b/engine/cocos2d/core/asset-manager/deprecated.js
@@ -677,7 +677,7 @@ Object.defineProperties(cc, {
             if (CC_DEBUG) {
                 if (onceWarns.loader) {
                     onceWarns.loader = false;
-                    cc.log('cc.loader is deprecated, use cc.assetManager instead please. See https://docs.cocos.com/creator/manual/zh/release-notes/asset-manager-upgrade-guide.html');
+                    cc.log('cc.loader is deprecated, use cc.assetManager instead please. See https://docs.cocos.com/creator/2.4/manual/zh/release-notes/asset-manager-upgrade-guide.html');
                 }
             }
             return loader;
diff --git a/engine/cocos2d/core/assets/CCSpriteFrame.js b/engine/cocos2d/core/assets/CCSpriteFrame.js
index 61b1263f..efee970f 100644
--- a/engine/cocos2d/core/assets/CCSpriteFrame.js
+++ b/engine/cocos2d/core/assets/CCSpriteFrame.js
@@ -383,11 +383,11 @@ let SpriteFrame = cc.Class(/** @lends cc.SpriteFrame# */{
         }
 
         if (!self._originalSize) {
-            self.setOriginalSize(cc.size(w, h));
+            self._originalSize = cc.size(w, h);
         }
 
         if (!self._offset) {
-            self.setOffset(cc.v2(0, 0));
+            self._offset = cc.v2(0, 0);
         }
 
         self._calculateUV();
diff --git a/engine/cocos2d/core/components/CCLabel.js b/engine/cocos2d/core/components/CCLabel.js
index 1630a4b3..2404005a 100644
--- a/engine/cocos2d/core/components/CCLabel.js
+++ b/engine/cocos2d/core/components/CCLabel.js
@@ -674,6 +674,18 @@ let Label = cc.Class({
         this._super();
     },
 
+    onRestore: CC_EDITOR && function () {
+        // Because undo/redo will not call onEnable/onDisable,
+        // we need call onEnable/onDisable manually to active/disactive children nodes.
+        if (this.enabledInHierarchy) {
+            this.node._renderComponent = null;
+            this.onEnable();
+        }
+        else {
+            this.onDisable();
+        }
+    },
+
     _nodeSizeChanged () {
         // Because the content size is automatically updated when overflow is NONE.
         // And this will conflict with the alignment of the CCWidget.
diff --git a/engine/cocos2d/core/components/CCMotionStreak.js b/engine/cocos2d/core/components/CCMotionStreak.js
index a2fb140a..df3cd99c 100644
--- a/engine/cocos2d/core/components/CCMotionStreak.js
+++ b/engine/cocos2d/core/components/CCMotionStreak.js
@@ -62,6 +62,7 @@ var MotionStreak = cc.Class({
     ctor () {
         this._points = [];
         this._lastWPos = new cc.Vec2();
+        this._lastWPosUpdated = false;
     },
 
     properties: {
@@ -313,8 +314,7 @@ var MotionStreak = cc.Class({
     reset () {
         this._points.length = 0;
         this._assembler && this._assembler._renderData.clear();
-        this._lastWPos.x = 0;
-        this._lastWPos.y = 0;
+        this._lastWPosUpdated = false;
         if (CC_EDITOR) {
             cc.engine.repaintInEditMode();
         }
diff --git a/engine/cocos2d/core/physics/CCPolygonSeparator.js b/engine/cocos2d/core/physics/CCPolygonSeparator.js
index 036f7c8d..06c997c9 100644
--- a/engine/cocos2d/core/physics/CCPolygonSeparator.js
+++ b/engine/cocos2d/core/physics/CCPolygonSeparator.js
@@ -68,14 +68,14 @@ function ConvexPartition(vertices) {
     var list = [];
     var d, lowerDist, upperDist;
     var p;
-    var lowerInt = cc.v2();
-    var upperInt = cc.v2(); // intersection points
+    var lowerInt = null;
+    var upperInt = null; // intersection points
     var lowerIndex = 0, upperIndex = 0;
     var lowerPoly, upperPoly;
     
     for (var i = 0; i < vertices.length; ++i) {
         if (Reflex(i, vertices)) {
-            lowerDist = upperDist = 10e7; // std::numeric_limits<qreal>::max();
+            lowerDist = upperDist = Number.MAX_SAFE_INTEGER || 9999999999999; // std::numeric_limits<qreal>::max();
             for (var j = 0; j < vertices.length; ++j) {
                 // if line intersects with an edge
                 if (Left(At(i - 1, vertices), At(i, vertices), At(j, vertices)) &&
diff --git a/engine/cocos2d/core/platform/CCMacro.js b/engine/cocos2d/core/platform/CCMacro.js
index 037ee54a..d277c1d3 100644
--- a/engine/cocos2d/core/platform/CCMacro.js
+++ b/engine/cocos2d/core/platform/CCMacro.js
@@ -316,12 +316,12 @@ cc.macro = {
 
     /**
      * !#en
-     * Whether to clear the original image cache after uploaded a texture to GPU. If cleared, [Dynamic Atlas](https://docs.cocos.com/creator/manual/en/advanced-topics/dynamic-atlas.html) will not be supported.
+     * Whether to clear the original image cache after uploaded a texture to GPU. If cleared, [Dynamic Atlas](https://docs.cocos.com/creator/2.4/manual/en/advanced-topics/dynamic-atlas.html) will not be supported.
      * Normally you don't need to enable this option on the web platform, because Image object doesn't consume too much memory.
      * But on WeChat Game platform, the current version cache decoded data in Image object, which has high memory usage.
      * So we enabled this option by default on WeChat, so that we can release Image cache immediately after uploaded to GPU.
      * !#zh
-     * 是否在将贴图上传至 GPU 之后删除原始图片缓存，删除之后图片将无法进行 [动态合图](https://docs.cocos.com/creator/manual/zh/advanced-topics/dynamic-atlas.html)。
+     * 是否在将贴图上传至 GPU 之后删除原始图片缓存，删除之后图片将无法进行 [动态合图](https://docs.cocos.com/creator/2.4/manual/zh/advanced-topics/dynamic-atlas.html)。
      * 在 Web 平台，你通常不需要开启这个选项，因为在 Web 平台 Image 对象所占用的内存很小。
      * 但是在微信小游戏平台的当前版本，Image 对象会缓存解码后的图片数据，它所占用的内存空间很大。
      * 所以我们在微信平台默认开启了这个选项，这样我们就可以在上传 GL 贴图之后立即释放 Image 对象的内存，避免过高的内存占用。
diff --git a/engine/cocos2d/core/renderer/utils/dynamic-atlas/manager.js b/engine/cocos2d/core/renderer/utils/dynamic-atlas/manager.js
index ecaf5558..801337a6 100644
--- a/engine/cocos2d/core/renderer/utils/dynamic-atlas/manager.js
+++ b/engine/cocos2d/core/renderer/utils/dynamic-atlas/manager.js
@@ -32,8 +32,8 @@ function beforeSceneLoad() {
 let _enabled = false;
 
 /**
- * !#en Manage Dynamic Atlas Manager. Dynamic Atlas Manager is used for merging textures at runtime, see [Dynamic Atlas](https://docs.cocos.com/creator/manual/en/advanced-topics/dynamic-atlas.html) for details.
- * !#zh 管理动态图集。动态图集用于在运行时对贴图进行合并，详见 [动态合图](https://docs.cocos.com/creator/manual/zh/advanced-topics/dynamic-atlas.html)。
+ * !#en Manage Dynamic Atlas Manager. Dynamic Atlas Manager is used for merging textures at runtime, see [Dynamic Atlas](https://docs.cocos.com/creator/2.4/manual/en/advanced-topics/dynamic-atlas.html) for details.
+ * !#zh 管理动态图集。动态图集用于在运行时对贴图进行合并，详见 [动态合图](https://docs.cocos.com/creator/2.4/manual/zh/advanced-topics/dynamic-atlas.html)。
  * @class DynamicAtlasManager
  */
 let dynamicAtlasManager = {
@@ -41,8 +41,8 @@ let dynamicAtlasManager = {
     Rect: Rect,
 
     /**
-     * !#en Enable or disable the dynamic atlas, see [Dynamic Atlas](https://docs.cocos.com/creator/manual/en/advanced-topics/dynamic-atlas.html) for details.
-     * !#zh 开启或者关闭动态图集，详见 [动态合图](https://docs.cocos.com/creator/manual/zh/advanced-topics/dynamic-atlas.html)。
+     * !#en Enable or disable the dynamic atlas, see [Dynamic Atlas](https://docs.cocos.com/creator/2.4/manual/en/advanced-topics/dynamic-atlas.html) for details.
+     * !#zh 开启或者关闭动态图集，详见 [动态合图](https://docs.cocos.com/creator/2.4/manual/zh/advanced-topics/dynamic-atlas.html)。
      * @property enabled
      * @type {Boolean}
      */
@@ -192,6 +192,7 @@ let dynamicAtlasManager = {
      * !#zh 添加碎图进入动态图集。
      * @method insertSpriteFrame
      * @param {SpriteFrame} spriteFrame
+     * @return {Object} frame
      */
     insertSpriteFrame(spriteFrame) {
         if (CC_EDITOR) return null;
diff --git a/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak-multi.js b/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak-multi.js
index 98141b32..5c345578 100644
--- a/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak-multi.js
+++ b/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak-multi.js
@@ -25,6 +25,8 @@
 
 import MotionStreakAssembler from "./motion-streak";
 import { vfmtPosUvColorTexId } from '../../webgl/vertex-format';
+import Mat4 from '../../../value-types/mat4';
+
 const MotionStreak = require('../../../components/CCMotionStreak');
 const RenderFlow = require('../../render-flow');
 
@@ -47,6 +49,7 @@ Point.prototype.setDir = function (x, y) {
 
 let _normal = cc.v2();
 let _vec2 = cc.v2();
+let _worldMat = new Mat4();
 
 function normal (out, dir) {
     //get perpendicular
@@ -74,14 +77,14 @@ export default class MultiMotionStreakAssembler extends MotionStreakAssembler {
         let stroke = comp._stroke / 2;
 
         let node = comp.node;
-        let matrix = node._worldMatrix.m;
-        let tx = matrix[12], ty = matrix[13];
+        node.getWorldMatrix(_worldMat);
+        let tx = _worldMat.m[12], ty = _worldMat.m[13];
 
         let points = comp._points;
         let lastPos = comp._lastWPos;
         let fadeTime = comp._fadeTime;
 
-        let moved = lastPos.x !== tx || lastPos.y !== ty;
+        let moved = comp._lastWPosUpdated && (lastPos.x !== tx || lastPos.y !== ty);
         if (moved) {
             let cur;
             let newHead = false;
@@ -126,7 +129,8 @@ export default class MultiMotionStreakAssembler extends MotionStreakAssembler {
 
         lastPos.x = tx;
         lastPos.y = ty;
-
+        comp._lastWPosUpdated = true;
+        
         if (points.length < 2) {
             return;
         }
diff --git a/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak.js b/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak.js
index b15433c6..477ca7ea 100644
--- a/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak.js
+++ b/engine/cocos2d/core/renderer/webgl/assemblers/motion-streak.js
@@ -24,6 +24,7 @@
  ****************************************************************************/
 
 import Assembler2D from '../../assembler-2d';
+import Mat4 from '../../../value-types/mat4';
 
 const RenderFlow = require('../../render-flow');
 
@@ -48,6 +49,7 @@ let _tangent = cc.v2();
 let _miter = cc.v2();
 let _normal = cc.v2();
 let _vec2 = cc.v2();
+let _worldMat = new Mat4();
 
 function normal (out, dir) {
     //get perpendicular
@@ -91,14 +93,14 @@ export default class MotionStreakAssembler extends Assembler2D {
         let stroke = comp._stroke / 2;
 
         let node = comp.node;
-        let matrix = node._worldMatrix.m;
-        let tx = matrix[12], ty = matrix[13];
+        node.getWorldMatrix(_worldMat);
+        let tx = _worldMat.m[12], ty = _worldMat.m[13];
 
         let points = comp._points;
         let lastPos = comp._lastWPos;
         let fadeTime = comp._fadeTime;
 
-        let moved = lastPos.x !== tx || lastPos.y !== ty;
+        let moved = comp._lastWPosUpdated && (lastPos.x !== tx || lastPos.y !== ty);
         if (moved) {
             let cur;
             let newHead = false;
@@ -143,7 +145,8 @@ export default class MotionStreakAssembler extends Assembler2D {
 
         lastPos.x = tx;
         lastPos.y = ty;
-
+        comp._lastWPosUpdated = true;
+        
         if (points.length < 2) {
             return;
         }
diff --git a/engine/cocos2d/particle/CCParticleSystem.js b/engine/cocos2d/particle/CCParticleSystem.js
index f063ad26..a4f28fbe 100644
--- a/engine/cocos2d/particle/CCParticleSystem.js
+++ b/engine/cocos2d/particle/CCParticleSystem.js
@@ -820,6 +820,18 @@ var ParticleSystem = cc.Class({
         }
     },
 
+    onRestore: CC_EDITOR && function () {
+        // Because undo/redo will not call onEnable/onDisable,
+        // we need call onEnable/onDisable manually to active/disactive children nodes.
+        if (this.enabledInHierarchy) {
+            this.node._renderComponent = null;
+            this.onEnable();
+        }
+        else {
+            this.onDisable();
+        }
+    },
+
     _startPreview: CC_EDITOR && function () {
         if (this.preview) {
             this.resetSystem();
diff --git a/engine/editor/i18n/en/localization.js b/engine/editor/i18n/en/localization.js
index 6972d7cb..a28187a6 100755
--- a/engine/editor/i18n/en/localization.js
+++ b/engine/editor/i18n/en/localization.js
@@ -1,33 +1,33 @@
 module.exports = {
     'COMPONENT': {
         "help_url": {
-            "audiosource": "https://docs.cocos.com/creator/manual/en/components/audiosource.html",
-            "animation": "https://docs.cocos.com/creator/manual/en/components/animation.html",
-            "sprite": "https://docs.cocos.com/creator/manual/en/components/sprite.html",
-            "label": "https://docs.cocos.com/creator/manual/en/components/label.html",
-            "canvas": "https://docs.cocos.com/creator/manual/en/components/canvas.html",
-            "spine": "https://docs.cocos.com/creator/manual/en/components/spine.html",
-            "widget": "https://docs.cocos.com/creator/manual/en/components/widget.html",
-            "button": "https://docs.cocos.com/creator/manual/en/components/button.html",
-            "progressbar": "https://docs.cocos.com/creator/manual/en/components/progress.html",
-            "mask": "https://docs.cocos.com/creator/manual/en/components/mask.html",
-            "scrollview": "https://docs.cocos.com/creator/manual/en/components/scrollview.html",
-            "scrollbar": "https://docs.cocos.com/creator/manual/en/components/scrollbar.html",
-            "layout": "https://docs.cocos.com/creator/manual/en/components/layout.html",
-            "tiledmap": "https://docs.cocos.com/creator/manual/en/components/tiledmap.html",
-            "editbox": "https://docs.cocos.com/creator/manual/en/components/editbox.html",
-            "videoplayer": "https://docs.cocos.com/creator/manual/en/components/videoplayer.html",
-            "motionStreak": "https://docs.cocos.com/creator/manual/en/components/motion-streak.html",
-            "richtext": "https://docs.cocos.com/creator/manual/en/components/richtext.html",
-            "pageview": "https://docs.cocos.com/creator/manual/en/components/pageview.html",
-            "pageviewIndicator": "https://docs.cocos.com/creator/manual/en/components/pageviewindicator.html",
-            "toggle": "https://docs.cocos.com/creator/manual/en/components/toggle.html",
-            "toggleGroup": "https://docs.cocos.com/creator/manual/en/components/toggleGroup.html",
-            "toggleContainer": "https://docs.cocos.com/creator/manual/en/components/toggleContainer.html",
-            "slider": "https://docs.cocos.com/creator/manual/en/components/slider.html",
-            "block_input_events": "https://docs.cocos.com/creator/manual/en/components/block-input-events.html",
-            "subcontext_view": "https://docs.cocos.com/creator/manual/en/publish/publish-wechatgame-sub-domain.html",
-            "safe_area": "https://docs.cocos.com/creator/manual/en/components/safearea.html"
+            "audiosource": "https://docs.cocos.com/creator/2.4/manual/en/components/audiosource.html",
+            "animation": "https://docs.cocos.com/creator/2.4/manual/en/components/animation.html",
+            "sprite": "https://docs.cocos.com/creator/2.4/manual/en/components/sprite.html",
+            "label": "https://docs.cocos.com/creator/2.4/manual/en/components/label.html",
+            "canvas": "https://docs.cocos.com/creator/2.4/manual/en/components/canvas.html",
+            "spine": "https://docs.cocos.com/creator/2.4/manual/en/components/spine.html",
+            "widget": "https://docs.cocos.com/creator/2.4/manual/en/components/widget.html",
+            "button": "https://docs.cocos.com/creator/2.4/manual/en/components/button.html",
+            "progressbar": "https://docs.cocos.com/creator/2.4/manual/en/components/progress.html",
+            "mask": "https://docs.cocos.com/creator/2.4/manual/en/components/mask.html",
+            "scrollview": "https://docs.cocos.com/creator/2.4/manual/en/components/scrollview.html",
+            "scrollbar": "https://docs.cocos.com/creator/2.4/manual/en/components/scrollbar.html",
+            "layout": "https://docs.cocos.com/creator/2.4/manual/en/components/layout.html",
+            "tiledmap": "https://docs.cocos.com/creator/2.4/manual/en/components/tiledmap.html",
+            "editbox": "https://docs.cocos.com/creator/2.4/manual/en/components/editbox.html",
+            "videoplayer": "https://docs.cocos.com/creator/2.4/manual/en/components/videoplayer.html",
+            "motionStreak": "https://docs.cocos.com/creator/2.4/manual/en/components/motion-streak.html",
+            "richtext": "https://docs.cocos.com/creator/2.4/manual/en/components/richtext.html",
+            "pageview": "https://docs.cocos.com/creator/2.4/manual/en/components/pageview.html",
+            "pageviewIndicator": "https://docs.cocos.com/creator/2.4/manual/en/components/pageviewindicator.html",
+            "toggle": "https://docs.cocos.com/creator/2.4/manual/en/components/toggle.html",
+            "toggleGroup": "https://docs.cocos.com/creator/2.4/manual/en/components/toggleGroup.html",
+            "toggleContainer": "https://docs.cocos.com/creator/2.4/manual/en/components/toggleContainer.html",
+            "slider": "https://docs.cocos.com/creator/2.4/manual/en/components/slider.html",
+            "block_input_events": "https://docs.cocos.com/creator/2.4/manual/en/components/block-input-events.html",
+            "subcontext_view": "https://docs.cocos.com/creator/2.4/manual/en/publish/publish-wechatgame-sub-domain.html",
+            "safe_area": "https://docs.cocos.com/creator/2.4/manual/en/components/safearea.html"
         },
         "animation": {
             "default_clip": "When checking, the deault animation clip is automatically played.",
diff --git a/engine/editor/i18n/zh/localization.js b/engine/editor/i18n/zh/localization.js
index 18de7d07..5d8ba326 100755
--- a/engine/editor/i18n/zh/localization.js
+++ b/engine/editor/i18n/zh/localization.js
@@ -1,33 +1,33 @@
 module.exports = {
     'COMPONENT': {
         "help_url": {
-            "audiosource": "https://docs.cocos.com/creator/manual/zh/components/audiosource.html",
-            "animation": "https://docs.cocos.com/creator/manual/zh/components/animation.html",
-            "sprite": "https://docs.cocos.com/creator/manual/zh/components/sprite.html",
-            "label": "https://docs.cocos.com/creator/manual/zh/components/label.html",
-            "canvas": "https://docs.cocos.com/creator/manual/zh/components/canvas.html",
-            "spine": "https://docs.cocos.com/creator/manual/zh/components/spine.html",
-            "widget": "https://docs.cocos.com/creator/manual/zh/components/widget.html",
-            "button": "https://docs.cocos.com/creator/manual/zh/components/button.html",
-            "progressbar": "https://docs.cocos.com/creator/manual/zh/components/progress.html",
-            "mask": "https://docs.cocos.com/creator/manual/zh/components/mask.html",
-            "scrollview": "https://docs.cocos.com/creator/manual/zh/components/scrollview.html",
-            "scrollbar": "https://docs.cocos.com/creator/manual/zh/components/scrollbar.html",
-            "layout": "https://docs.cocos.com/creator/manual/zh/components/layout.html",
-            "tiledmap": "https://docs.cocos.com/creator/manual/zh/components/tiledmap.html",
-            "editbox": "https://docs.cocos.com/creator/manual/zh/components/editbox.html",
-            "videoplayer": "https://docs.cocos.com/creator/manual/zh/components/videoplayer.html",
-            "motionStreak": "https://docs.cocos.com/creator/manual/zh/components/motion-streak.html",
-            "richtext": "https://docs.cocos.com/creator/manual/zh/components/richtext.html",
-            "pageview": "https://docs.cocos.com/creator/manual/zh/components/pageview.html",
-            "pageviewIndicator": "https://docs.cocos.com/creator/manual/zh/components/pageviewindicator.html",
-            "toggle": "https://docs.cocos.com/creator/manual/zh/components/toggle.html",
-            "toggleGroup": "https://docs.cocos.com/creator/manual/zh/components/toggleGroup.html",
-            "toggleContainer": "https://docs.cocos.com/creator/manual/zh/components/toggleContainer.html",
-            "slider": "https://docs.cocos.com/creator/manual/zh/components/slider.html",
-            "block_input_events": "https://docs.cocos.com/creator/manual/zh/components/block-input-events.html",
-            "subcontext_view": "https://docs.cocos.com/creator/manual/zh/publish/publish-wechatgame-sub-domain.html",
-            "safe_area": "https://docs.cocos.com/creator/manual/zh/components/safearea.html",
+            "audiosource": "https://docs.cocos.com/creator/2.4/manual/zh/components/audiosource.html",
+            "animation": "https://docs.cocos.com/creator/2.4/manual/zh/components/animation.html",
+            "sprite": "https://docs.cocos.com/creator/2.4/manual/zh/components/sprite.html",
+            "label": "https://docs.cocos.com/creator/2.4/manual/zh/components/label.html",
+            "canvas": "https://docs.cocos.com/creator/2.4/manual/zh/components/canvas.html",
+            "spine": "https://docs.cocos.com/creator/2.4/manual/zh/components/spine.html",
+            "widget": "https://docs.cocos.com/creator/2.4/manual/zh/components/widget.html",
+            "button": "https://docs.cocos.com/creator/2.4/manual/zh/components/button.html",
+            "progressbar": "https://docs.cocos.com/creator/2.4/manual/zh/components/progress.html",
+            "mask": "https://docs.cocos.com/creator/2.4/manual/zh/components/mask.html",
+            "scrollview": "https://docs.cocos.com/creator/2.4/manual/zh/components/scrollview.html",
+            "scrollbar": "https://docs.cocos.com/creator/2.4/manual/zh/components/scrollbar.html",
+            "layout": "https://docs.cocos.com/creator/2.4/manual/zh/components/layout.html",
+            "tiledmap": "https://docs.cocos.com/creator/2.4/manual/zh/components/tiledmap.html",
+            "editbox": "https://docs.cocos.com/creator/2.4/manual/zh/components/editbox.html",
+            "videoplayer": "https://docs.cocos.com/creator/2.4/manual/zh/components/videoplayer.html",
+            "motionStreak": "https://docs.cocos.com/creator/2.4/manual/zh/components/motion-streak.html",
+            "richtext": "https://docs.cocos.com/creator/2.4/manual/zh/components/richtext.html",
+            "pageview": "https://docs.cocos.com/creator/2.4/manual/zh/components/pageview.html",
+            "pageviewIndicator": "https://docs.cocos.com/creator/2.4/manual/zh/components/pageviewindicator.html",
+            "toggle": "https://docs.cocos.com/creator/2.4/manual/zh/components/toggle.html",
+            "toggleGroup": "https://docs.cocos.com/creator/2.4/manual/zh/components/toggleGroup.html",
+            "toggleContainer": "https://docs.cocos.com/creator/2.4/manual/zh/components/toggleContainer.html",
+            "slider": "https://docs.cocos.com/creator/2.4/manual/zh/components/slider.html",
+            "block_input_events": "https://docs.cocos.com/creator/2.4/manual/zh/components/block-input-events.html",
+            "subcontext_view": "https://docs.cocos.com/creator/2.4/manual/zh/publish/publish-wechatgame-sub-domain.html",
+            "safe_area": "https://docs.cocos.com/creator/2.4/manual/zh/components/safearea.html",
         },
         'animation': {
             'default_clip': '在勾选自动播放或调用 play() 时默认播放的动画 clip。',
diff --git a/engine/package.json b/engine/package.json
index b174ca46..9d5cd85a 100644
--- a/engine/package.json
+++ b/engine/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cocos-creator-js",
-  "version": "2.4.9",
+  "version": "2.4.10",
   "description": "Cocos Creator is a complete package of game development tools and workflow, including a game engine, resource management, scene editing, game preview, debug and publish one project to multiple platforms.",
   "homepage": "https://www.cocos.com",
   "license": "MIT",
diff --git a/engine/predefine.js b/engine/predefine.js
index a385b894..1d6e9458 100644
--- a/engine/predefine.js
+++ b/engine/predefine.js
@@ -132,7 +132,7 @@ function defineDeprecatedMacroGetter (name, defaultValue) {
                     recommandedUsage = 'cc.sys.platform === cc.sys.WECHAT_GAME_SUB';
                 }
                 else if (name === 'CC_WECHATGAME') {
-                    recommandedUsage = 'cc.sys.platform === cc.sys.WECHAT_GAME';                    
+                    recommandedUsage = 'cc.sys.platform === cc.sys.WECHAT_GAME';
                 }
                 else if (name === 'CC_QQPLAY') {
                     recommandedUsage = 'cc.sys.platform === cc.sys.QQ_PLAY';
@@ -185,7 +185,7 @@ else {
     defineMacro('CC_JSB', defined('jsb') && !CC_RUNTIME);
 }
 
-// deprecated 
+// deprecated
 const WECHATGAMESUB = !!(defined('wx') && wx.getSharedCanvas);
 const WECHATGAME = !!(defined('wx') && (wx.getSystemInfoSync || wx.getSharedCanvas));
 const QQPLAY = defined('bk');
@@ -211,5 +211,5 @@ if (CC_DEV) {
  * If you post a bug to forum, please attach this flag.
  * @property {String} ENGINE_VERSION
  */
-const engineVersion = '2.4.9';
+const engineVersion = '2.4.10';
 _global['CocosEngine'] = cc.ENGINE_VERSION = engineVersion;
diff --git a/jsb-adapter/engine/assemblers/motion-streak-multi.js b/jsb-adapter/engine/assemblers/motion-streak-multi.js
index 1df4efc6..a42d3ec3 100644
--- a/jsb-adapter/engine/assemblers/motion-streak-multi.js
+++ b/jsb-adapter/engine/assemblers/motion-streak-multi.js
@@ -3,8 +3,6 @@ let proto = cc.MotionStreak.__assembler__.MultiMotionStreakAssembler.prototype;
 let _update = proto.update;
 cc.js.mixin(proto, {
     update (comp, dt) {
-        comp.node._updateWorldMatrix();
-        
         _update.call(this, comp, dt);
 
         let { iData, usedVertices } = this._renderData._flexBuffer;
diff --git a/jsb-adapter/engine/assemblers/motion-streak.js b/jsb-adapter/engine/assemblers/motion-streak.js
index 8ad9648a..fd076c06 100644
--- a/jsb-adapter/engine/assemblers/motion-streak.js
+++ b/jsb-adapter/engine/assemblers/motion-streak.js
@@ -11,8 +11,6 @@ cc.js.mixin(proto, {
         this.ignoreOpacityFlag();
     },
     update (comp, dt) {
-        comp.node._updateWorldMatrix();
-        
         _update.call(this, comp, dt);
 
         let { iData, usedVertices } = this._renderData._flexBuffer;