Merge pull request #2933 from evazion/feat-doc-cosplay-autotags

Fix #2931: mention automated implications on *_(cosplay) wikis.

app/logical/post_sets/post.rb

@@ -37,6 +37,11 @@ module PostSets
       end
     end
 
+    def tag
+      return nil if !is_single_tag?
+      @tag ||= Tag.find_by(name: Tag.normalize_name(tag_string))
+    end
+
     def has_artist?
       is_single_tag? && artist.present? && artist.visible?
     end