New approach to sorting file response, fixes #336 (take two)

src/js/helpers.js

@@ -1224,6 +1224,10 @@ export let createRange = function (indexes){
  **/
 export let sortItems = function (array, property, reverse = false, sort_map = null){
 
+	if (!array || array.length <= 0){
+		return [];
+	}
+
 	function compare(a,b){
 
 		var a_value = a;

src/js/services/mopidy/middleware.js

@@ -2262,10 +2262,8 @@ const MopidyMiddleware = (function(){
                         for (var item of response){
                             if (item.type === "track"){
                                 tracks_uris.push(item.uri);
-                                tracks_uris = helpers.sortItems(tracks_uris, 'name');
                             } else {
                                 subdirectories.push(item);
-                                subdirectories = helpers.sortItems(subdirectories, 'name');
                             }
                         }
                         

src/js/views/library/LibraryBrowse.js

@@ -152,7 +152,10 @@ class LibraryBrowse extends React.Component{
 		}
 
 		var tracks = (this.props.directory.tracks && this.props.directory.tracks.length > 0 ? this.props.directory.tracks : null);
+		tracks = helpers.sortItems(tracks, 'name');
+		
 		var subdirectories = (this.props.directory.subdirectories && this.props.directory.subdirectories.length > 0 ? this.props.directory.subdirectories : null);
+		subdirectories = helpers.sortItems(subdirectories, 'name');
 
 		var view_options = [
 			{