fix cc.sys.os && audio downloading on Alipay iOS

common/engine/Loader.js

@@ -83,7 +83,7 @@ function downloadImage (item, callback, isCrossOrigin) {
 
 function downloadAudio (item, callback) {
     if (cc.sys.__audioSupport.format.length === 0) {
-        return new Error(debug.getError(4927));
+        return new Error(cc.debug.getError(4927));
     }
 
     var dom = document.createElement('audio');

common/engine/globalAdapter/BaseSystemInfo.js

@@ -14,13 +14,15 @@ let systemInfo = {
         sys.languageCode = env.language.toLowerCase();
         var system = env.system.toLowerCase();
 
-        if (env.platform === "android") {
+        let platform = env.platform;
+        platform = platform.toLowerCase();
+        if (platform === "android") {
             sys.os = sys.OS_ANDROID;
         }
-        else if (env.platform === "ios") {
+        else if (platform === "ios") {
             sys.os = sys.OS_IOS;
         }
-        else if (env.platform === 'devtools') {
+        else if (platform === 'devtools') {
             sys.isMobile = false;
             if (system.indexOf('android') > -1) {
                 sys.os = sys.OS_ANDROID;

platforms/alipay/wrapper/engine/Loader.js

@@ -7,4 +7,30 @@ cc.loader.downloader.loadSubpackage = function (name, completeCallback) {
         loadedSubPackages[name] = true;
     }
     completeCallback && completeCallback();
-};
+};
+
+function downloadAudio (item, callback) {
+    if (cc.sys.__audioSupport.format.length === 0) {
+        return new Error(cc.debug.getError(4927));
+    }
+
+    let audio = my.createInnerAudioContext();
+    audio.onCanPlay(() => {
+      callback(null, audio);
+    });
+    audio.onError(() => {
+      callback(new Error('load audio failed ' + item.url), null);
+    });
+    audio.src = item.url;
+}
+
+// FIX audio downlaod error on Alipay iOS 10.1.78
+if (cc.sys.os === cc.sys.OS_IOS) {
+    cc.loader.downloader.addHandlers({
+        // Audio
+        mp3 : downloadAudio,
+        ogg : downloadAudio,
+        wav : downloadAudio,
+        m4a : downloadAudio,
+    });
+}