fix(download): ensure rangefetcher loads before abstractfile; skip queryString for blob; add Range probe

public/src/js/assets.js

@@ -36,10 +36,10 @@ var assets = {
 		"account.js",
 		"lyrics.js",
 		"customsongs.js",
+		"rangefetcher.js",
 		"abstractfile.js",
 		"idb.js",
 		"plugins.js",
-		"rangefetcher.js",
 		"search.js"
 	],
 	"css": [

public/src/js/loader.js

@@ -576,7 +576,8 @@ class Loader{
 	}
 	loadScript(url){
 		var script = document.createElement("script")
-		var url = url + this.queryString
+		var isBlob = typeof url === "string" && (url.startsWith("blob:") || url.startsWith("data:"))
+		var url = isBlob ? url : (url + this.queryString)
 		var promise = pageEvents.load(script)
 		script.src = url
 		document.head.appendChild(script)

public/src/js/rangefetcher.js

@@ -47,11 +47,26 @@ var RangeFetcher = {
             r.send()
         })
     },
+    _probeRange: function(url){
+        return new Promise(function(resolve){
+            var r = new XMLHttpRequest()
+            r.open("GET", url)
+            r.responseType = "arraybuffer"
+            r.setRequestHeader("Range", "bytes=0-0")
+            r.onload = function(){
+                var ok = r.status === 206 && !!r.getResponseHeader("Content-Range")
+                resolve(ok)
+            }
+            r.onerror = function(){ resolve(false) }
+            r.send()
+        })
+    },
     _runConcurrent: function(tasks, limit){
         return new Promise(function(resolve, reject){
             var i = 0
             var running = 0
             var results = []
+            var done = 0
             function next(){
                 while(running < limit && i < tasks.length){
                     var idx = i++
@@ -59,7 +74,8 @@ var RangeFetcher = {
                     tasks[idx]().then(function(res){
                         results[idx] = res
                         running--
-                        if(results.length === tasks.length && results.every(function(v){return v !== undefined})){ resolve(results) }
+                        done++
+                        if(done === tasks.length){ resolve(results) }
                         else{ next() }
                     }, function(e){ reject(e) })
                 }
@@ -73,9 +89,17 @@ var RangeFetcher = {
         var minChunk = opts.chunkSize || 1048576
         var self = this
         return this._head(url).then(function(info){
-            if(!info.length || !info.acceptRanges || info.length < minChunk){
+            if(!info.length || info.length < minChunk){
                 return self._getAll(url, "arraybuffer")
             }
+            if(!info.acceptRanges){
+                return self._probeRange(url).then(function(supported){
+                    if(!supported){
+                        return self._getAll(url, "arraybuffer")
+                    }
+                    return supported
+                })
+            }
             var total = info.length
             var parts = Math.ceil(total / minChunk)
             parts = Math.max(1, Math.min(parts, 16))
@@ -103,4 +127,4 @@ var RangeFetcher = {
     fetchText: function(url, opts){
         return this.fetchBlob(url, opts).then(function(blob){ return blob.text() })
     }
-}
+}