Fix song previews

public/src/js/songselect.js

@@ -3,7 +3,7 @@ function SongSelect(){
 	var _songs;
 	var _selectedSong = {title:'', folder:'', difficulty:''};
 	var _preview;
-	var _preview_ended
+	var _preview_id = 0
 	var _diffNames={
 		easy:"かんたん",
 		normal:"ふつう",
@@ -14,7 +14,7 @@ function SongSelect(){
 	this.startPreview = function(id, prvtime, first_open=true) {
 		_this.endPreview();
 		var startLoad = +new Date
-		_preview_ended = false
+		var current_id = _preview_id
 		if(first_open){
 			snd.musicGain.fadeOut(0.4)
 		}
@@ -30,7 +30,7 @@ function SongSelect(){
 			this.previewLoaded(startLoad, prvtime, first_open)
 		}else{
 			snd.previewGain.load("/songs/" + id + "/main.mp3").then(sound => {
-				if(!_preview_ended){
+				if(current_id == _preview_id){
 					songObj.sound = sound
 					_preview = sound
 					this.previewLoaded(startLoad, prvtime, first_open)
@@ -48,7 +48,7 @@ function SongSelect(){
 	}
 	
 	this.endPreview = function() {
-		_preview_ended = true
+		_preview_id++
 		if (_preview) {
 			_preview.stop();
 		};

public/src/js/soundbuffer.js

@@ -124,7 +124,9 @@ class Sound{
 	playLoop(time, absolute, seek1, seek2, until){
 		time = this.convertTime(time, absolute)
 		seek1 = seek1 || 0
-		seek2 = seek2 || 0
+		if(typeof seek2 == "undefined"){
+			seek2 = seek1
+		}
 		until = until || this.duration
 		this.loop = {
 			started: time + until - seek1,