FIX: maintain category ordering when position is fixed for browsing

FEATURE: allow mods to set category ordering for topic creation dialog
  using fixed_category_positions_on_create

app/assets/javascripts/discourse/components/category-chooser.js.es6

@@ -26,7 +26,11 @@ export default ComboboxView.extend({
   }.property('scopedCategoryId', 'categories'),
 
   _setCategories: function() {
-    this.set('categories', this.get('categories') || Discourse.Category.list());
+    this.set('categories', this.get('categories') || (
+        Discourse.SiteSettings.fixed_category_positions_on_create ?
+          Discourse.Category.list() : Discourse.Category.listByActivity()
+        )
+    );
   }.on('init'),
 
   none: function() {

app/assets/javascripts/discourse/models/category.js

@@ -216,6 +216,14 @@ Discourse.Category.reopenClass({
   },
 
   list: function() {
+    if (Discourse.SiteSettings.fixed_category_positions) {
+      return Discourse.Site.currentProp('categories');
+    } else {
+      return Discourse.Site.currentProp('sortedCategories');
+    }
+  },
+
+  listByActivity: function() {
     return Discourse.Site.currentProp('sortedCategories');
   },
 

config/locales/server.en.yml

@@ -768,6 +768,7 @@ en:
     category_featured_topics: "Number of topics displayed per category on the /categories page. After changing this value, it takes up to 15 minutes for the categories page to update."
     show_subcategory_list: "Show subcategory list instead of topic list when entering a category."
     fixed_category_positions: "If checked, you will be able to arrange categories into a fixed order. If unchecked, categories are listed in order of activity."
+    fixed_category_positions_on_create: "If checked, category ordering will be maintained on topic creation dialog (requires fixed_category_positions)."
     add_rel_nofollow_to_user_content: "Add rel nofollow to all submitted user content, except for internal links (including parent domains). If you change this, you must rebake all posts with: \"rake posts:rebake\""
     exclude_rel_nofollow_domains: "A list of domains where nofollow should not be added to links. tld.com will automatically allow sub.tld.com as well. As a minimum, you should add the top-level domain of this site to help web crawlers find all content. If other parts of your website are at other domains, add those too."
 

config/site_settings.yml

@@ -168,6 +168,11 @@ basic:
   fixed_category_positions:
     client: true
     default: false
+
+  fixed_category_positions_on_create:
+    client: true
+    default: false
+
   show_subcategory_list:
     default: false
     client: true