FIX: Some errors that only appear in Ember 1.13

app/assets/javascripts/discourse-common/lib/helpers.js.es6

@@ -3,8 +3,11 @@ import { get } from 'discourse-common/lib/raw-handlebars';
 // `Ember.Helper` is only available in versions after 1.12
 export function htmlHelper(fn) {
   if (Ember.Helper) {
-    return Ember.Helper.helper(function() {
-      return new Handlebars.SafeString(fn.apply(this, Array.prototype.slice.call(arguments)) || '');
+    return Ember.Helper.helper(function(...args) {
+      if (args.length > 1) {
+        args[1] = { hash: args[1] };
+      }
+      return new Handlebars.SafeString(fn.apply(this, args) || '');
     });
   } else {
     return Ember.Handlebars.makeBoundHelper(function() {

app/assets/javascripts/discourse/controllers/discovery/categories.js.es6

@@ -20,7 +20,10 @@ export default DiscoveryController.extend({
   @computed("model.parentCategory")
   categoryPageStyle(parentCategory) {
     const style = this.siteSettings.desktop_category_page_style;
-    return parentCategory && style === "categories_and_latest_topics" ? "categories_only" : style;
+    const componentName = (parentCategory && style === "categories_and_latest_topics") ?
+                          "categories_only" :
+                          style;
+    return Ember.String.dasherize(componentName);
   }
 
 });

app/assets/javascripts/discourse/helpers/user-status.js.es6

@@ -6,8 +6,8 @@ export default htmlHelper((user, args) => {
   if (!user) { return; }
 
   const name = escapeExpression(user.get('name'));
-  let currentUser = args.currentUser;
-  if (!currentUser && args.hash) {
+  let currentUser;
+  if (args && args.hash) {
     currentUser = args.hash.currentUser;
   }