Tags: don't allow deprecation of tags without wiki

app/policies/tag_policy.rb

@@ -8,13 +8,14 @@ class TagPolicy < ApplicationPolicy
   end
 
   def can_change_deprecated_status?
+    return false if record.wiki_page.blank? && !record.is_deprecated?
     user.is_admin? || (record.post_count == 0 && !record.is_deprecated?)
   end
 
   def permitted_attributes
-    [
-      (:category if can_change_category?),
-      (:is_deprecated if can_change_deprecated_status?),
-    ].compact
+    permitted = []
+    permitted << :category if can_change_category?
+    permitted << :is_deprecated if can_change_deprecated_status?
+    permitted
   end
 end