[Haml] Fix our monkeypatch of safe_concat.

doc-src/HAML_CHANGELOG.md

@@ -3,6 +3,11 @@
 * Table of contents
 {:toc}
 
+## 2.2.19 (Unreleased)
+
+* Fix a bug with the integration with Rails' XSS support.
+  In particular, correctly override `safe_concat`.
+
 ## 2.2.18
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/2.2.18).

lib/haml/helpers/xss_mods.rb

@@ -114,7 +114,7 @@ module ActionView
           if is_haml?
             haml_buffer.buffer.concat(string)
           else
-            concat_without_haml(string)
+            safe_concat_without_haml(string)
           end
         end
         alias_method :safe_concat_without_haml, :safe_concat