Only update favorite icon if the operation was successful

Also shows a notification in case an error occured on updating the tags

apps/files/js/tagsplugin.js

@@ -105,12 +105,12 @@
 					} else {
 						tags.push(OC.TAG_FAVORITE);
 					}
-					toggleStar($actionEl, !isFavorite);
 
 					self.applyFileTags(
 						dir + '/' + fileName,
 						tags
 					).then(function(result) {
+						toggleStar($actionEl, !isFavorite);
 						// response from server should contain updated tags
 						var newTags = result.tags;
 						if (_.isUndefined(newTags)) {
@@ -171,6 +171,8 @@
 				}),
 				dataType: 'json',
 				type: 'POST'
+			}).fail(function() {
+				OC.Notification.showTemporary(t('files', 'An error occurred while trying to update the tags'));
 			});
 		}
 	};