FIX: tag input says tags are optional when they're required

app/assets/javascripts/discourse/app/controllers/topic.js

@@ -185,6 +185,13 @@ export default Controller.extend(bufferedProperty("model"), {
     );
   },
 
+  @discourseComputed("model.category")
+  minimumRequiredTags(category) {
+    return category && category.minimum_required_tags > 0
+      ? category.minimum_required_tags
+      : null;
+  },
+
   _forceRefreshPostStream() {
     this.appEvents.trigger("post-stream:refresh", { force: true });
   },

app/assets/javascripts/discourse/app/templates/topic.hbs

@@ -36,6 +36,7 @@
                 options=(hash
                   filterable=true
                   categoryId=buffered.category_id
+                  minimum=minimumRequiredTags
                 )
               }}
             {{/if}}