FIX: use separate site attribute for single category "top tags" list.

And use it only in the single category pages.
38dd184a16

app/assets/javascripts/discourse/routes/build-topic-route.js.es6

@@ -67,7 +67,11 @@ function findTopicList(store, tracking, filter, filterParams, extras) {
     }
     Session.currentProp("topicList", list);
     if (list.topic_list && list.topic_list.top_tags) {
-      Site.currentProp("top_tags", list.topic_list.top_tags);
+      if (list.filter.startsWith("c/")) {
+        Site.currentProp("category_top_tags", list.topic_list.top_tags);
+      } else {
+        Site.currentProp("top_tags", list.topic_list.top_tags);
+      }
     }
     return list;
   });

app/assets/javascripts/select-kit/components/tag-drop.js.es6

@@ -107,7 +107,19 @@ export default ComboBoxComponent.extend(TagsMixin, {
     return shortcuts;
   }),
 
-  topTags: readOnly("site.top_tags.[]"),
+  topTags: computed(
+    "firstCategory",
+    "secondCategory",
+    "site.category_top_tags.[]",
+    "site.top_tags.[]",
+    function() {
+      if (this.currentCategory && this.site.category_top_tags) {
+        return this.site.category_top_tags;
+      }
+
+      return this.site.top_tags;
+    }
+  ),
 
   content: computed("topTags.[]", "shortcuts.[]", function() {
     if (this.sortTagsAlphabetically && this.topTags) {