FIX: default user preferenced categories are not updating in admin site setting UI.

app/assets/javascripts/admin/components/site-setting.js.es6

@@ -6,16 +6,24 @@ import showModal from "discourse/lib/show-modal";
 import AboutRoute from "discourse/routes/about";
 
 export default Component.extend(BufferedContent, SettingComponent, {
+  updateExistingUsers: null,
+
   _save() {
+    const setting = this.buffered;
+    return SiteSetting.update(setting.get("setting"), setting.get("value"), {
+      updateExistingUsers: this.updateExistingUsers
+    });
+  },
+
+  actions: {
+    update() {
       const defaultCategoriesSettings = [
         "default_categories_watching",
         "default_categories_tracking",
         "default_categories_muted",
         "default_categories_watching_first_post"
       ];
-    const setting = this.buffered;
+      const key = this.buffered.get("setting");
-    const key = setting.get("setting");
-    const value = setting.get("value");
 
       if (defaultCategoriesSettings.includes(key)) {
         AboutRoute.create()
@@ -30,13 +38,13 @@ export default Component.extend(BufferedContent, SettingComponent, {
             });
 
             controller.set("onClose", () => {
-            return SiteSetting.update(key, value, {
+              this.updateExistingUsers = controller.updateExistingUsers;
-              updateExistingUsers: controller.updateExistingUsers
+              this.send("save");
-            });
             });
           });
       } else {
-      return SiteSetting.update(key, value);
+        this.send("save");
+      }
     }
   }
 });

app/assets/javascripts/admin/templates/components/site-setting.hbs

@@ -6,7 +6,7 @@
 </div>
 {{#if dirty}}
   <div class='setting-controls'>
-    {{d-button class="ok" action=(action "save") icon="check"}}
+    {{d-button class="ok" action=(action "update") icon="check"}}
     {{d-button class="cancel" action=(action "cancel") icon="times"}}
   </div>
 {{else if setting.overridden}}